[lyx.git] / src / Buffer.cpp

/**
 * \file Buffer.cpp
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author Lars Gullik Bjønnes
 * \author Stefan Schimanski
 *
 * Full author contact details are available in file CREDITS.
 */

#include <config.h>

#include "Buffer.h"

#include "Author.h"
#include "BiblioInfo.h"
#include "BranchList.h"
#include "buffer_funcs.h"
#include "BufferList.h"
#include "BufferParams.h"
#include "Bullet.h"
#include "Chktex.h"
#include "ColorSet.h"
#include "Converter.h"
#include "Counters.h"
#include "Cursor.h"
#include "CutAndPaste.h"
#include "DispatchResult.h"
#include "DocIterator.h"
#include "BufferEncodings.h"
#include "ErrorList.h"
#include "Exporter.h"
#include "Format.h"
#include "FuncRequest.h"
#include "FuncStatus.h"
#include "IndicesList.h"
#include "InsetIterator.h"
#include "InsetList.h"
#include "Language.h"
#include "LaTeXFeatures.h"
#include "LaTeX.h"
#include "Layout.h"
#include "Lexer.h"
#include "LyXAction.h"
#include "LyX.h"
#include "LyXRC.h"
#include "LyXVC.h"
#include "output.h"
#include "output_latex.h"
#include "output_docbook.h"
#include "output_plaintext.h"
#include "output_xhtml.h"
#include "Paragraph.h"
#include "ParagraphParameters.h"
#include "ParIterator.h"
#include "PDFOptions.h"
#include "Session.h"
#include "SpellChecker.h"
#include "xml.h"
#include "texstream.h"
#include "TexRow.h"
#include "Text.h"
#include "TextClass.h"
#include "TocBackend.h"
#include "Undo.h"
#include "VCBackend.h"
#include "version.h"
#include "WordLangTuple.h"

#include "insets/InsetBranch.h"
#include "insets/InsetInclude.h"
#include "insets/InsetText.h"

#include "mathed/InsetMathHull.h"
#include "mathed/MacroTable.h"
#include "mathed/InsetMathMacroTemplate.h"
#include "mathed/MathSupport.h"

#include "graphics/PreviewLoader.h"

#include "frontends/Application.h"
#include "frontends/alert.h"
#include "frontends/Delegates.h"
#include "frontends/WorkAreaManager.h"

#include "support/lassert.h"
#include "support/convert.h"
#include "support/debug.h"
#include "support/docstring_list.h"
#include "support/ExceptionMessage.h"
#include "support/FileMonitor.h"
#include "support/FileName.h"
#include "support/FileNameList.h"
#include "support/filetools.h"
#include "support/gettext.h"
#include "support/gzstream.h"
#include "support/lstrings.h"
#include "support/mutex.h"
#include "support/os.h"
#include "support/Package.h"
#include "support/PathChanger.h"
#include "support/Systemcall.h"
#include "support/TempFile.h"
#include "support/textutils.h"
#include "support/types.h"

#include <algorithm>
#include <fstream>
#include <iomanip>
#include <map>
#include <memory>
#include <set>
#include <sstream>
#include <vector>

using namespace std;
using namespace lyx::support;
using namespace lyx::graphics;

namespace lyx {

namespace Alert = frontend::Alert;
namespace os = support::os;

namespace {

int const LYX_FORMAT = LYX_FORMAT_LYX;

typedef map<string, bool> DepClean;

// Information about labels and their associated refs
struct LabelInfo {
        /// label string
        docstring label;
        /// label inset
        InsetLabel const * inset;
        /// associated references cache
        Buffer::References references;
        /// whether this label is active (i.e., not deleted)
        bool active;
};

typedef vector<LabelInfo> LabelCache;

typedef map<docstring, Buffer::References> RefCache;

// A storehouse for the cloned buffers.
typedef list<CloneList_ptr> CloneStore;
CloneStore cloned_buffers;

} // namespace



class Buffer::Impl
{
public:
        Impl(Buffer * owner, FileName const & file, bool readonly, Buffer const * cloned_buffer);

        ~Impl()
        {
                delete preview_loader_;
                if (wa_) {
                        wa_->closeAll();
                        delete wa_;
                }
                delete inset;
        }

        /// search for macro in local (buffer) table or in children
        MacroData const * getBufferMacro(docstring const & name,
                DocIterator const & pos) const;

        /// Update macro table starting with position of it \param it in some
        /// text inset.
        void updateMacros(DocIterator & it, DocIterator & scope);
        ///
        void setLabel(ParIterator & it, UpdateType utype) const;

        /** If we have branches that use the file suffix
            feature, return the file name with suffix appended.
        */
        FileName exportFileName() const;

        Buffer * owner_;

        BufferParams params;
        LyXVC lyxvc;
        FileName temppath;
        mutable TexRow texrow;

        /// need to regenerate .tex?
        DepClean dep_clean;

        /// name of the file the buffer is associated with.
        FileName filename;

        ///
        mutable TocBackend toc_backend;

        /// macro tables
        struct ScopeMacro {
                ScopeMacro() {}
                ScopeMacro(DocIterator const & s, MacroData const & m)
                        : scope(s), macro(m) {}
                DocIterator scope;
                MacroData macro;
        };
        typedef map<DocIterator, ScopeMacro> PositionScopeMacroMap;
        typedef map<docstring, PositionScopeMacroMap> NamePositionScopeMacroMap;
        /// map from the macro name to the position map,
        /// which maps the macro definition position to the scope and the MacroData.
        NamePositionScopeMacroMap macros;

        /// positions of child buffers in the buffer
        typedef map<Buffer const * const, DocIterator> BufferPositionMap;
        struct ScopeBuffer {
                ScopeBuffer() : buffer(nullptr) {}
                ScopeBuffer(DocIterator const & s, Buffer const * b)
                        : scope(s), buffer(b) {}
                DocIterator scope;
                Buffer const * buffer;
        };
        typedef map<DocIterator, ScopeBuffer> PositionScopeBufferMap;
        /// position of children buffers in this buffer
        BufferPositionMap children_positions;
        /// map from children inclusion positions to their scope and their buffer
        PositionScopeBufferMap position_to_children;

        /// Contains the old buffer filePath() while saving-as, or the
        /// directory where the document was last saved while loading.
        string old_position;

        /** Keeps track of the path of local layout files.
         *  If possible, it is always relative to the buffer path.
         *  Empty for layouts in system or user directory.
         */
        string layout_position;

        /// Container for all sort of Buffer dependant errors.
        map<string, ErrorList> errorLists;

        /// checksum used to test if the file has been externally modified.  Used to
        /// double check whether the file had been externally modified when saving.
        unsigned long checksum_;

        ///
        frontend::WorkAreaManager * wa_;
        ///
        frontend::GuiBufferDelegate * gui_;

        ///
        Undo undo_;

        /// A cache for the bibfiles (including bibfiles of loaded child
        /// documents), needed for appropriate update of natbib labels.
        mutable docstring_list bibfiles_cache_;

        // FIXME The caching mechanism could be improved. At present, we have a
        // cache for each Buffer, that caches all the bibliography info for that
        // Buffer. A more efficient solution would be to have a global cache per
        // file, and then to construct the Buffer's bibinfo from that.
        /// A cache for bibliography info
        mutable BiblioInfo bibinfo_;
        /// Cache of timestamps of .bib files
        map<FileName, time_t> bibfile_status_;

        /// These two hold the file name and format, written to by
        /// Buffer::preview and read from by LFUN_BUFFER_VIEW_CACHE.
        FileName preview_file_;
        string preview_format_;

        /// Cache the references associated to a label and their positions
        /// in the buffer.
        mutable RefCache ref_cache_;
        /// Cache the label insets and their activity status.
        mutable LabelCache label_cache_;

        /// our Text that should be wrapped in an InsetText
        InsetText * inset;

        ///
        PreviewLoader * preview_loader_;

        /// If non zero, this buffer is a clone of existing buffer \p cloned_buffer_
        /// This one is useful for preview detached in a thread.
        Buffer const * cloned_buffer_;
        ///
        CloneList_ptr clone_list_;

        ///
        std::list<Buffer const *> include_list_;
private:
        /// So we can force access via the accessors.
        mutable Buffer const * parent_buffer;

        FileMonitorPtr file_monitor_;

/// ints and bools are all listed last so as to avoid alignment issues
public:
        /// original format of loaded file
        int file_format;

        /// are we in the process of exporting this buffer?
        mutable bool doing_export;

        /// If there was an error when previewing, on the next preview we do
        /// a fresh compile (e.g. in case the user installed a package that
        /// was missing).
        bool require_fresh_start_;

        /// Indicates whether the bibinfo has changed since the last time
        /// we ran updateBuffer(), i.e., whether citation labels may need
        /// to be updated.
        mutable bool cite_labels_valid_;
        /// Do we have a bibliography environment?
        mutable bool have_bibitems_;

        /// is save needed?
        mutable bool lyx_clean;

        /// is autosave needed?
        mutable bool bak_clean;

        /// is this an unnamed file (New...)?
        bool unnamed;

        /// is this an internal bufffer?
        bool internal_buffer;

        /// buffer is r/o
        bool read_only;

        /** Set to true only when the file is fully loaded.
         *  Used to prevent the premature generation of previews
         *  and by the citation inset.
         */
        bool file_fully_loaded;

        /// if the file was originally loaded from an older format, do
        /// we need to back it up still?
        bool need_format_backup;

        /// Ignore the parent (e.g. when exporting a child standalone)?
        bool ignore_parent;

        /// This seem to change the way Buffer::getMacro() works
        mutable bool macro_lock;

        /// has been externally modified? Can be reset by the user.
        mutable bool externally_modified_;

        /// whether the bibinfo cache is valid
        mutable bool bibinfo_cache_valid_;

        ///
        mutable bool need_update;

private:
        int word_count_;
        int char_count_;
        int blank_count_;

public:
        /// This is here to force the test to be done whenever parent_buffer
        /// is accessed.
        Buffer const * parent() const
        {
                // ignore_parent temporarily "orphans" a buffer
                // (e.g. if a child is compiled standalone)
                if (ignore_parent)
                        return nullptr;
                // if parent_buffer is not loaded, then it has been unloaded,
                // which means that parent_buffer is an invalid pointer. So we
                // set it to null in that case.
                // however, the BufferList doesn't know about cloned buffers, so
                // they will always be regarded as unloaded. in that case, we hope
                // for the best.
                if (!cloned_buffer_ && !theBufferList().isLoaded(parent_buffer))
                        parent_buffer = nullptr;
                return parent_buffer;
        }

        ///
        void setParent(Buffer const * pb)
        {
                if (parent_buffer == pb)
                        // nothing to do
                        return;
                if (!cloned_buffer_ && parent_buffer && pb)
                        LYXERR0("Warning: a buffer should not have two parents!");
                parent_buffer = pb;
                if (!cloned_buffer_ && parent_buffer)
                        parent_buffer->invalidateBibinfoCache();
        }

        /// compute statistics
        /// \p from initial position
        /// \p to points to the end position
        void updateStatistics(DocIterator & from, DocIterator & to,
                              bool skipNoOutput = true);
        /// statistics accessor functions
        int wordCount() const
        {
                return word_count_;
        }
        int charCount(bool with_blanks) const
        {
                return char_count_
                + (with_blanks ? blank_count_ : 0);
        }

        // Make sure the file monitor monitors the good file.
        void refreshFileMonitor();

        /// Notify or clear of external modification
        void fileExternallyModified(bool exists);

        ///Binding LaTeX lines with buffer positions.
        //Common routine for LaTeX and Reference errors listing.
        void traverseErrors(TeXErrors::Errors::const_iterator err,
                TeXErrors::Errors::const_iterator end,
                ErrorList & errorList) const;
};


/// Creates the per buffer temporary directory
static FileName createBufferTmpDir()
{
        // FIXME This would be the ideal application for a TempDir class (like
        //       TempFile but for directories)
        string counter;
        {
                static int count;
                static Mutex mutex;
                Mutex::Locker locker(&mutex);
                counter = convert<string>(count++);
        }
        // We are in our own directory.  Why bother to mangle name?
        // In fact I wrote this code to circumvent a problematic behaviour
        // (bug?) of EMX mkstemp().
        FileName tmpfl(package().temp_dir().absFileName() + "/lyx_tmpbuf" +
                counter);

        if (!tmpfl.createDirectory(0777)) {
                throw ExceptionMessage(WarningException, _("Disk Error: "), bformat(
                        _("LyX could not create the temporary directory '%1$s' (Disk is full maybe?)"),
                        from_utf8(tmpfl.absFileName())));
        }
        return tmpfl;
}


Buffer::Impl::Impl(Buffer * owner, FileName const & file, bool readonly_,
        Buffer const * cloned_buffer)
        : owner_(owner), filename(file), toc_backend(owner), checksum_(0),
          wa_(nullptr),  gui_(nullptr), undo_(*owner), inset(nullptr),
          preview_loader_(nullptr), cloned_buffer_(cloned_buffer),
          clone_list_(nullptr), parent_buffer(nullptr), file_format(LYX_FORMAT),
          doing_export(false), require_fresh_start_(false), cite_labels_valid_(false),
          have_bibitems_(false), lyx_clean(true), bak_clean(true), unnamed(false),
          internal_buffer(false), read_only(readonly_), file_fully_loaded(false),
          need_format_backup(false), ignore_parent(false), macro_lock(false),
          externally_modified_(false), bibinfo_cache_valid_(false),
          need_update(false), word_count_(0), char_count_(0), blank_count_(0)
{
        refreshFileMonitor();
        if (!cloned_buffer_) {
                temppath = createBufferTmpDir();
                lyxvc.setBuffer(owner_);
                Language const * inplang = theApp() ?
                                        languages.getFromCode(theApp()->inputLanguageCode())
                                      : nullptr;
                if (inplang)
                        params.language = inplang;
                if (use_gui)
                        wa_ = new frontend::WorkAreaManager;
                return;
        }
        temppath = cloned_buffer_->d->temppath;
        file_fully_loaded = true;
        params = cloned_buffer_->d->params;
        bibfiles_cache_ = cloned_buffer_->d->bibfiles_cache_;
        bibinfo_ = cloned_buffer_->d->bibinfo_;
        bibinfo_cache_valid_ = cloned_buffer_->d->bibinfo_cache_valid_;
        bibfile_status_ = cloned_buffer_->d->bibfile_status_;
        cite_labels_valid_ = cloned_buffer_->d->cite_labels_valid_;
        have_bibitems_ = cloned_buffer_->d->have_bibitems_;
        unnamed = cloned_buffer_->d->unnamed;
        internal_buffer = cloned_buffer_->d->internal_buffer;
        layout_position = cloned_buffer_->d->layout_position;
        preview_file_ = cloned_buffer_->d->preview_file_;
        preview_format_ = cloned_buffer_->d->preview_format_;
        require_fresh_start_ = cloned_buffer_->d->require_fresh_start_;
}


Buffer::Buffer(string const & file, bool readonly, Buffer const * cloned_buffer)
        : d(new Impl(this, FileName(file), readonly, cloned_buffer))
{
        LYXERR(Debug::INFO, "Buffer::Buffer()");
        if (cloned_buffer) {
                d->inset = new InsetText(*cloned_buffer->d->inset);
                d->inset->setBuffer(*this);
                // FIXME: optimize this loop somewhat, maybe by creating a new
                // general recursive Inset::setId().
                DocIterator it = doc_iterator_begin(this);
                DocIterator cloned_it = doc_iterator_begin(cloned_buffer);
                for (; !it.atEnd(); it.forwardPar(), cloned_it.forwardPar())
                        it.paragraph().setId(cloned_it.paragraph().id());
        } else
                d->inset = new InsetText(this);
        d->inset->getText(0)->setMacrocontextPosition(par_iterator_begin());
}


Buffer::~Buffer()
{
        LYXERR(Debug::INFO, "Buffer::~Buffer()");
        // here the buffer should take care that it is
        // saved properly, before it goes into the void.

        // GuiView already destroyed
        d->gui_ = nullptr;

        if (isInternal()) {
                // No need to do additional cleanups for internal buffer.
                delete d;
                return;
        }

        if (isClone()) {
                // this is in case of recursive includes: we won't try to delete
                // ourselves as a child.
                d->clone_list_->erase(this);
                // loop over children
                for (auto const & p : d->children_positions) {
                        Buffer * child = const_cast<Buffer *>(p.first);
                        if (d->clone_list_->erase(child))
                                delete child;
                }
                // if we're the master buffer, then we should get rid of the list
                // of clones
                if (!parent()) {
                        // If this is not empty, we have leaked something. Worse, one of the
                        // children still has a reference to this list. But we will try to
                        // continue, rather than shut down.
                        LATTEST(d->clone_list_->empty());
                        // The clone list itself is empty, but it's still referenced in our list
                        // of clones. So let's find it and remove it.
                        CloneStore::iterator it =
                                find(cloned_buffers.begin(), cloned_buffers.end(), d->clone_list_);
                        if (it == cloned_buffers.end()) {
                                // We will leak in this case, but it is safe to continue.
                                LATTEST(false);
                        } else
                                cloned_buffers.erase(it);
                }
                // FIXME Do we really need to do this right before we delete d?
                // clear references to children in macro tables
                d->children_positions.clear();
                d->position_to_children.clear();
        } else {
                // loop over children
                for (auto const & p : d->children_positions) {
                        Buffer * child = const_cast<Buffer *>(p.first);
                        if (theBufferList().isLoaded(child)) {
                                if (theBufferList().isOthersChild(this, child))
                                        child->setParent(nullptr);
                                else
                                        theBufferList().release(child);
                        }
                }

                if (!isClean()) {
                        docstring msg = _("LyX attempted to close a document that had unsaved changes!\n");
                        try {
                                msg += emergencyWrite();
                        } catch (...) {
                                msg += "  " + _("Save failed! Document is lost.");
                        }
                        Alert::warning(_("Attempting to close changed document!"), msg);
                }

                // FIXME Do we really need to do this right before we delete d?
                // clear references to children in macro tables
                d->children_positions.clear();
                d->position_to_children.clear();

                if (!d->temppath.destroyDirectory()) {
                        LYXERR0(bformat(_("Could not remove the temporary directory %1$s"),
                                from_utf8(d->temppath.absFileName())));
                }
                removePreviews();
        }

        delete d;
}


Buffer * Buffer::cloneWithChildren() const
{
        BufferMap bufmap;
        cloned_buffers.emplace_back(new CloneList);
        CloneList_ptr clones = cloned_buffers.back();

        cloneWithChildren(bufmap, clones);

        // make sure we got cloned
        BufferMap::const_iterator bit = bufmap.find(this);
        LASSERT(bit != bufmap.end(), return nullptr);
        Buffer * cloned_buffer = bit->second;

        return cloned_buffer;
}


void Buffer::cloneWithChildren(BufferMap & bufmap, CloneList_ptr clones) const
{
        // have we already been cloned?
        if (bufmap.find(this) != bufmap.end())
                return;

        Buffer * buffer_clone = new Buffer(fileName().absFileName(), false, this);

        // The clone needs its own DocumentClass, since running updateBuffer() will
        // modify it, and we would otherwise be sharing it with the original Buffer.
        buffer_clone->params().makeDocumentClass(true);
        cap::switchBetweenClasses(
                        params().documentClassPtr(), buffer_clone->params().documentClassPtr(),
                        static_cast<InsetText &>(buffer_clone->inset()));

        bufmap[this] = buffer_clone;
        clones->insert(buffer_clone);
        buffer_clone->d->clone_list_ = clones;
        buffer_clone->d->macro_lock = true;
        buffer_clone->d->children_positions.clear();

        // FIXME (Abdel 09/01/2010): this is too complicated. The whole children_positions and
        // math macro caches need to be rethought and simplified.
        // I am not sure wether we should handle Buffer cloning here or in BufferList.
        // Right now BufferList knows nothing about buffer clones.
        for (auto const & p : d->position_to_children) {
                DocIterator dit = p.first.clone(buffer_clone);
                dit.setBuffer(buffer_clone);
                Buffer * child = const_cast<Buffer *>(p.second.buffer);

                child->cloneWithChildren(bufmap, clones);
                BufferMap::iterator const bit = bufmap.find(child);
                LASSERT(bit != bufmap.end(), continue);
                Buffer * child_clone = bit->second;

                Inset * inset = dit.nextInset();
                LASSERT(inset && inset->lyxCode() == INCLUDE_CODE, continue);
                InsetInclude * inset_inc = static_cast<InsetInclude *>(inset);
                inset_inc->setChildBuffer(child_clone);
                child_clone->d->setParent(buffer_clone);
                // FIXME Do we need to do this now, or can we wait until we run updateMacros()?
                buffer_clone->setChild(dit, child_clone);
        }
        buffer_clone->d->macro_lock = false;
}


Buffer * Buffer::cloneBufferOnly() const {
        cloned_buffers.emplace_back(new CloneList);
        CloneList_ptr clones = cloned_buffers.back();
        Buffer * buffer_clone = new Buffer(fileName().absFileName(), false, this);

        // The clone needs its own DocumentClass, since running updateBuffer() will
        // modify it, and we would otherwise be sharing it with the original Buffer.
        buffer_clone->params().makeDocumentClass(true);
        cap::switchBetweenClasses(
                        params().documentClassPtr(), buffer_clone->params().documentClassPtr(),
                        static_cast<InsetText &>(buffer_clone->inset()));

        clones->insert(buffer_clone);
        buffer_clone->d->clone_list_ = clones;

        // we won't be cloning the children
        buffer_clone->d->children_positions.clear();
        return buffer_clone;
}


bool Buffer::isClone() const
{
        return d->cloned_buffer_;
}


void Buffer::changed(bool update_metrics) const
{
        if (d->wa_)
                d->wa_->redrawAll(update_metrics);
}


frontend::WorkAreaManager & Buffer::workAreaManager() const
{
        LBUFERR(d->wa_);
        return *d->wa_;
}


Text & Buffer::text() const
{
        return d->inset->text();
}


Inset & Buffer::inset() const
{
        return *d->inset;
}


BufferParams & Buffer::params()
{
        return d->params;
}


BufferParams const & Buffer::params() const
{
        return d->params;
}


BufferParams const & Buffer::masterParams() const
{
        if (masterBuffer() == this)
                return params();

        BufferParams & mparams = const_cast<Buffer *>(masterBuffer())->params();
        // Copy child authors to the params. We need those pointers.
        for (Author const & a : params().authors())
                mparams.authors().record(a);
        return mparams;
}


double Buffer::fontScalingFactor() const
{
        return isExporting() ? 75.0 * params().html_math_img_scale
                : 0.01 * lyxrc.dpi * lyxrc.currentZoom * lyxrc.preview_scale_factor * params().display_pixel_ratio;
}


ParagraphList & Buffer::paragraphs()
{
        return text().paragraphs();
}


ParagraphList const & Buffer::paragraphs() const
{
        return text().paragraphs();
}


LyXVC & Buffer::lyxvc()
{
        return d->lyxvc;
}


LyXVC const & Buffer::lyxvc() const
{
        return d->lyxvc;
}


string const Buffer::temppath() const
{
        return d->temppath.absFileName();
}


TexRow & Buffer::texrow()
{
        return d->texrow;
}


TexRow const & Buffer::texrow() const
{
        return d->texrow;
}


TocBackend & Buffer::tocBackend() const
{
        return d->toc_backend;
}


Undo & Buffer::undo()
{
        return d->undo_;
}


void Buffer::setChild(DocIterator const & dit, Buffer * child)
{
        d->children_positions[child] = dit;
}


string Buffer::latexName(bool const no_path) const
{
        FileName latex_name =
                makeLatexName(d->exportFileName());
        return no_path ? latex_name.onlyFileName()
                : latex_name.absFileName();
}


FileName Buffer::Impl::exportFileName() const
{
        docstring const branch_suffix =
                params.branchlist().getFileNameSuffix();
        if (branch_suffix.empty())
                return filename;

        string const name = addExtension(filename.onlyFileNameWithoutExt()
                        + to_utf8(branch_suffix), filename.extension());
        FileName res(filename.onlyPath().absFileName() + "/" + name);

        return res;
}


string Buffer::logName(LogType * type) const
{
        string const filename = latexName(false);

        if (filename.empty()) {
                if (type)
                        *type = latexlog;
                return string();
        }

        string const path = temppath();

        FileName const fname(addName(temppath(),
                                     onlyFileName(changeExtension(filename,
                                                                  ".log"))));

        // FIXME: how do we know this is the name of the build log?
        FileName const bname(
                addName(path, onlyFileName(
                        changeExtension(filename,
                                        theFormats().extension(params().bufferFormat()) + ".out"))));

        // Also consider the master buffer log file
        FileName masterfname = fname;
        LogType mtype = latexlog;
        if (masterBuffer() != this) {
                string const mlogfile = masterBuffer()->logName(&mtype);
                masterfname = FileName(mlogfile);
        }

        // If no Latex log or Build log is newer, show Build log
        if (bname.exists() &&
            ((!fname.exists() && !masterfname.exists())
             || (fname.lastModified() < bname.lastModified()
                 && masterfname.lastModified() < bname.lastModified()))) {
                LYXERR(Debug::FILES, "Log name calculated as: " << bname);
                if (type)
                        *type = buildlog;
                return bname.absFileName();
        // If we have a newer master file log or only a master log, show this
        } else if (fname != masterfname
                   && (!fname.exists() && (masterfname.exists()
                   || fname.lastModified() < masterfname.lastModified()))) {
                LYXERR(Debug::FILES, "Log name calculated as: " << masterfname);
                if (type)
                        *type = mtype;
                return masterfname.absFileName();
        }
        LYXERR(Debug::FILES, "Log name calculated as: " << fname);
        if (type)
                        *type = latexlog;
        return fname.absFileName();
}


void Buffer::setReadonly(bool const flag)
{
        if (d->read_only != flag) {
                d->read_only = flag;
                changed(false);
        }
}


void Buffer::setFileName(FileName const & fname)
{
        bool const changed = fname != d->filename;
        d->filename = fname;
        d->refreshFileMonitor();
        if (changed)
                lyxvc().file_found_hook(fname);
        setReadonly(d->filename.isReadOnly());
        saveCheckSum();
        updateTitles();
}


int Buffer::readHeader(Lexer & lex)
{
        int unknown_tokens = 0;
        int line = -1;
        int begin_header_line = -1;

        // Initialize parameters that may be/go lacking in header:
        params().branchlist().clear();
        params().preamble.erase();
        params().options.erase();
        params().master.erase();
        params().float_placement.erase();
        params().float_alignment.erase();
        params().paperwidth.erase();
        params().paperheight.erase();
        params().leftmargin.erase();
        params().rightmargin.erase();
        params().topmargin.erase();
        params().bottommargin.erase();
        params().headheight.erase();
        params().headsep.erase();
        params().footskip.erase();
        params().columnsep.erase();
        params().font_roman_opts.erase();
        params().font_sans_opts.erase();
        params().font_typewriter_opts.erase();
        params().fonts_cjk.erase();
        params().listings_params.clear();
        params().clearLayoutModules();
        params().clearRemovedModules();
        params().clearIncludedChildren();
        params().pdfoptions().clear();
        params().indiceslist().clear();
        params().backgroundcolor = lyx::rgbFromHexName("#ffffff");
        params().isbackgroundcolor = false;
        params().fontcolor = RGBColor(0, 0, 0);
        params().isfontcolor = false;
        params().notefontcolor = RGBColor(0xCC, 0xCC, 0xCC);
        params().isnotefontcolor = false;
        params().boxbgcolor = RGBColor(0xFF, 0, 0);
        params().isboxbgcolor = false;
        params().html_latex_start.clear();
        params().html_latex_end.clear();
        params().html_math_img_scale = 1.0;
        params().output_sync_macro.erase();
        params().setLocalLayout(docstring(), false);
        params().setLocalLayout(docstring(), true);
        params().biblio_opts.erase();
        params().biblatex_bibstyle.erase();
        params().biblatex_citestyle.erase();
        params().multibib.erase();
        params().lineno_opts.clear();
        params().spellignore().clear();

        for (int i = 0; i < 4; ++i) {
                params().user_defined_bullet(i) = ITEMIZE_DEFAULTS[i];
                params().temp_bullet(i) = ITEMIZE_DEFAULTS[i];
        }

        ErrorList & errorList = d->errorLists["Parse"];

        while (lex.isOK()) {
                string token;
                lex >> token;

                if (token.empty())
                        continue;

                if (token == "\\end_header")
                        break;

                ++line;
                if (token == "\\begin_header") {
                        begin_header_line = line;
                        continue;
                }

                LYXERR(Debug::PARSER, "Handling document header token: `"
                                      << token << '\'');

                string const result =
                        params().readToken(lex, token, d->filename);
                if (!result.empty()) {
                        if (token == "\\textclass") {
                                d->layout_position = result;
                        } else {
                                ++unknown_tokens;
                                docstring const s = bformat(_("Unknown token: "
                                                                        "%1$s %2$s\n"),
                                                         from_utf8(token),
                                                         lex.getDocString());
                                errorList.push_back(ErrorItem(_("Document header error"), s));
                        }
                }
        }
        if (begin_header_line) {
                docstring const s = _("\\begin_header is missing");
                errorList.push_back(ErrorItem(_("Document header error"), s));
        }

        params().shell_escape = theSession().shellescapeFiles().find(absFileName());

        params().makeDocumentClass(isClone(), isInternal());

        return unknown_tokens;
}


// Uwe C. Schroeder
// changed to be public and have one parameter
// Returns true if "\end_document" is not read (Asger)
bool Buffer::readDocument(Lexer & lex)
{
        ErrorList & errorList = d->errorLists["Parse"];
        errorList.clear();

        // remove dummy empty par
        paragraphs().clear();

        if (!lex.checkFor("\\begin_document")) {
                docstring const s = _("\\begin_document is missing");
                errorList.push_back(ErrorItem(_("Document header error"), s));
        }

        readHeader(lex);

        if (params().output_changes) {
                bool xcolorulem = LaTeXFeatures::isAvailable("ulem") &&
                                  LaTeXFeatures::isAvailable("xcolor");

                if (!xcolorulem) {
                        Alert::warning(_("Changes not shown in LaTeX output"),
                                       _("Changes will not be highlighted in LaTeX output, "
                                         "because xcolor and ulem are not installed.\n"
                                         "Please install both packages or redefine "
                                         "\\lyxadded and \\lyxdeleted in the LaTeX preamble."));
                }
        }

        if (!parent() && !params().master.empty()) {
                FileName const master_file = makeAbsPath(params().master,
                           onlyPath(absFileName()));
                if (isLyXFileName(master_file.absFileName())) {
                        Buffer * master =
                                checkAndLoadLyXFile(master_file, true);
                        if (master) {
                                // necessary e.g. after a reload
                                // to re-register the child (bug 5873)
                                // FIXME: clean up updateMacros (here, only
                                // child registering is needed).
                                master->updateMacros();
                                // set master as master buffer, but only
                                // if we are a real child
                                if (master->isChild(this))
                                        setParent(master);
                                // if the master is not fully loaded
                                // it is probably just loading this
                                // child. No warning needed then.
                                else if (master->isFullyLoaded())
                                        LYXERR0("The master '"
                                                << params().master
                                                << "' assigned to this document ("
                                                << absFileName()
                                                << ") does not include "
                                                "this document. Ignoring the master assignment.");
                                // If the master has just been created, un-hide it (#11162)
                                if (!master->fileName().exists())
                                        lyx::dispatch(FuncRequest(LFUN_BUFFER_SWITCH,
                                                                  master->absFileName()));
                        }
                }
        }

        // assure we have a default index
        params().indiceslist().addDefault(B_("Index"));

        // read main text
        if (FileName::isAbsolute(params().origin))
                d->old_position = params().origin;
        else
                d->old_position = filePath();

        if (!parent())
                clearIncludeList();

        bool const res = text().read(lex, errorList, d->inset);
        d->old_position.clear();

        // inform parent buffer about local macros
        if (parent()) {
                Buffer const * pbuf = parent();
                for (auto const & m : usermacros)
                        pbuf->usermacros.insert(m);
        }
        usermacros.clear();
        updateMacros();
        updateMacroInstances(InternalUpdate);
        return res;
}


bool Buffer::isSyncTeXenabled() const
{
        bool enabled = params().output_sync;

        if (!enabled)
                for (auto const & c : theConverters()) {
                        const string dest = c.to().substr(0,3);
                        if (dest == "dvi" || dest == "pdf") {
                                const string cmd = c.command();
                                enabled |= cmd.find("-synctex=") != string::npos
                                        && cmd.find("-synctex=0") == string::npos;
                                if (enabled)
                                        break;
                        }
                }
        return enabled;
}

bool Buffer::importString(string const & format, docstring const & contents, ErrorList & errorList)
{
        Format const * fmt = theFormats().getFormat(format);
        if (!fmt)
                return false;
        // It is important to use the correct extension here, since some
        // converters create a wrong output file otherwise (e.g. html2latex)
        FileName const name = tempFileName("Buffer_importStringXXXXXX." + fmt->extension());
        ofdocstream os(name.toFilesystemEncoding().c_str());
        // Do not convert os implicitly to bool, since that is forbidden in C++11.
        bool const success = !(os << contents).fail();
        os.close();

        bool converted = false;
        if (success) {
                params().compressed = false;

                // remove dummy empty par
                paragraphs().clear();

                converted = importFile(format, name, errorList);
        }

        removeTempFile(name);
        return converted;
}


bool Buffer::importFile(string const & format, FileName const & name, ErrorList & errorList)
{
        if (!theConverters().isReachable(format, "lyx"))
                return false;

        FileName const lyx = tempFileName("Buffer_importFileXXXXXX.lyx");
        Converters::RetVal const retval =
                theConverters().convert(this, name, lyx, name, format, "lyx", errorList);
        if (retval == Converters::SUCCESS) {
                bool const success = readFile(lyx) == ReadSuccess;
                removeTempFile(lyx);
                return success;
        }

        return false;
}


bool Buffer::readString(string const & s)
{
        params().compressed = false;

        Lexer lex;
        istringstream is(s);
        lex.setStream(is);
        TempFile tempfile("Buffer_readStringXXXXXX.lyx");
        FileName const fn = tempfile.name();

        int file_format;
        bool success = parseLyXFormat(lex, fn, file_format) == ReadSuccess;

        if (success && file_format != LYX_FORMAT) {
                // We need to call lyx2lyx, so write the input to a file
                ofstream os(fn.toFilesystemEncoding().c_str());
                os << s;
                os.close();
                // lyxvc in readFile
                if (readFile(fn) != ReadSuccess)
                        success = false;
        }
        else if (success)
                if (readDocument(lex))
                        success = false;
        return success;
}


Buffer::ReadStatus Buffer::readFile(FileName const & fn)
{
        Lexer lex;
        if (!lex.setFile(fn)) {
                Alert::error(_("File Not Found"),
                        bformat(_("Unable to open file `%1$s'."),
                                from_utf8(fn.absFileName())));
                return ReadFileNotFound;
        }

        int file_format;
        ReadStatus const ret_plf = parseLyXFormat(lex, fn, file_format);
        if (ret_plf != ReadSuccess)
                return ret_plf;

        if (file_format != LYX_FORMAT) {
                FileName tmpFile;
                ReadStatus ret_clf = convertLyXFormat(fn, tmpFile, file_format);
                if (ret_clf != ReadSuccess)
                        return ret_clf;
                ret_clf = readFile(tmpFile);
                if (ret_clf == ReadSuccess) {
                        d->file_format = file_format;
                        d->need_format_backup = true;
                }
                return ret_clf;
        }

        // FIXME: InsetInfo needs to know whether the file is under VCS
        // during the parse process, so this has to be done before.
        lyxvc().file_found_hook(d->filename);

        if (readDocument(lex)) {
                Alert::error(_("Document format failure"),
                        bformat(_("%1$s ended unexpectedly, which means"
                                " that it is probably corrupted."),
                                        from_utf8(fn.absFileName())));
                return ReadDocumentFailure;
        }

        d->file_fully_loaded = true;
        d->read_only = !d->filename.isWritable();
        params().compressed = theFormats().isZippedFile(d->filename);
        saveCheckSum();
        return ReadSuccess;
}


bool Buffer::isFullyLoaded() const
{
        return d->file_fully_loaded;
}


void Buffer::setFullyLoaded(bool value)
{
        d->file_fully_loaded = value;
}


bool Buffer::freshStartRequired() const
{
        return d->require_fresh_start_;
}

void Buffer::requireFreshStart(bool const b) const
{
        d->require_fresh_start_ = b;
}


PreviewLoader * Buffer::loader() const
{
        if (!isExporting() && lyxrc.preview == LyXRC::PREVIEW_OFF)
                return nullptr;
        if (!d->preview_loader_)
                d->preview_loader_ = new PreviewLoader(*this);
        return d->preview_loader_;
}


void Buffer::removePreviews() const
{
        delete d->preview_loader_;
        d->preview_loader_ = nullptr;
}


void Buffer::updatePreviews() const
{
        PreviewLoader * ploader = loader();
        if (!ploader)
                return;

        InsetIterator it = begin(*d->inset);
        InsetIterator const itend = end(*d->inset);
        for (; it != itend; ++it)
                it->addPreview(it, *ploader);

        ploader->startLoading();
}


Buffer::ReadStatus Buffer::parseLyXFormat(Lexer & lex,
        FileName const & fn, int & file_format) const
{
        if(!lex.checkFor("\\lyxformat")) {
                Alert::error(_("Document format failure"),
                        bformat(_("%1$s is not a readable LyX document."),
                                from_utf8(fn.absFileName())));
                return ReadNoLyXFormat;
        }

        string tmp_format;
        lex >> tmp_format;

        // LyX formats 217 and earlier were written as 2.17. This corresponds
        // to files from LyX versions < 1.1.6.3. We just remove the dot in
        // these cases. See also: www.lyx.org/trac/changeset/1313.
        size_t dot = tmp_format.find_first_of(".,");
        if (dot != string::npos)
                tmp_format.erase(dot, 1);

        file_format = convert<int>(tmp_format);
        return ReadSuccess;
}


Buffer::ReadStatus Buffer::convertLyXFormat(FileName const & fn,
        FileName & tmpfile, int from_format)
{
        TempFile tempfile("Buffer_convertLyXFormatXXXXXX.lyx");
        tempfile.setAutoRemove(false);
        tmpfile = tempfile.name();
        if(tmpfile.empty()) {
                Alert::error(_("Conversion failed"),
                        bformat(_("%1$s is from a different"
                                " version of LyX, but a temporary"
                                " file for converting it could"
                                " not be created."),
                                from_utf8(fn.absFileName())));
                return LyX2LyXNoTempFile;
        }

        FileName const lyx2lyx = libFileSearch("lyx2lyx", "lyx2lyx");
        if (lyx2lyx.empty()) {
                Alert::error(_("Conversion script not found"),
                     bformat(_("%1$s is from a different"
                               " version of LyX, but the"
                               " conversion script lyx2lyx"
                               " could not be found."),
                               from_utf8(fn.absFileName())));
                return LyX2LyXNotFound;
        }

        // Run lyx2lyx:
        //   $python$ "$lyx2lyx$" -t $LYX_FORMAT$ -o "$tempfile$" "$filetoread$"
        ostringstream command;
        command << os::python()
                << ' ' << quoteName(lyx2lyx.toFilesystemEncoding())
                << " -t " << convert<string>(LYX_FORMAT)
                << " -o " << quoteName(tmpfile.toSafeFilesystemEncoding())
                << ' ' << quoteName(fn.toSafeFilesystemEncoding());
        string const command_str = command.str();

        LYXERR(Debug::INFO, "Running '" << command_str << '\'');

        cmd_ret const ret = runCommand(command_str);
        if (!ret.valid) {
                if (from_format < LYX_FORMAT) {
                        Alert::error(_("Conversion script failed"),
                                bformat(_("%1$s is from an older version"
                                        " of LyX and the lyx2lyx script"
                                        " failed to convert it."),
                                        from_utf8(fn.absFileName())));
                        return LyX2LyXOlderFormat;
                } else {
                        Alert::error(_("Conversion script failed"),
                                bformat(_("%1$s is from a newer version"
                                        " of LyX and the lyx2lyx script"
                                        " failed to convert it."),
                                        from_utf8(fn.absFileName())));
                        return LyX2LyXNewerFormat;
                }
        }
        return ReadSuccess;
}


FileName Buffer::getBackupName() const {
        map<int, string> const file_formats = {
          {544, "23"},
          {508, "22"},
          {474, "21"},
          {413, "20"},
          {345, "16"},
          {276, "15"},
          {245, "14"},
          {221, "13"},
          {220, "12"},
          {218, "1163"},
          {217, "116"},
          {216, "115"},
          {215, "11"},
          {210, "010"},
          {200, "006"}
        };
        FileName const & fn = fileName();
        string const fname = fn.onlyFileNameWithoutExt();
        string const fext  = fn.extension() + "~";
        string const fpath = lyxrc.backupdir_path.empty() ?
                fn.onlyPath().absFileName() :
                lyxrc.backupdir_path;
        string backup_suffix;
        // If file format is from a stable series use version instead of file format
        auto const it = file_formats.find(d->file_format);
        if (it != file_formats.end())
                backup_suffix = "-lyx" + it->second;
        else
                backup_suffix = "-lyxformat-" + convert<string>(d->file_format);
        string const backname = fname + backup_suffix;
        FileName backup(addName(fpath, addExtension(backname, fext)));

        // limit recursion, just in case
        int v = 1;
        unsigned long orig_checksum = 0;
        while (backup.exists() && v < 100) {
                if (orig_checksum == 0)
                        orig_checksum = fn.checksum();
                unsigned long new_checksum = backup.checksum();
                if (orig_checksum == new_checksum) {
                        LYXERR(Debug::FILES, "Not backing up " << fn <<
                               "since " << backup << "has the same checksum.");
                        // a bit of a hack, but we have to check this anyway
                        // below, and setting this is simpler than introducing
                        // a special boolean for this purpose.
                        v = 1000;
                        break;
                }
                string const newbackname = backname + "-" + convert<string>(v);
                backup.set(addName(fpath, addExtension(newbackname, fext)));
                v++;
        }
        return v < 100 ? backup : FileName();
}


// Should probably be moved to somewhere else: BufferView? GuiView?
bool Buffer::save() const
{
        docstring const file = makeDisplayPath(absFileName(), 20);
        d->filename.refresh();

        // check the read-only status before moving the file as a backup
        if (d->filename.exists()) {
                bool const read_only = !d->filename.isWritable();
                if (read_only) {
                        Alert::warning(_("File is read-only"),
                                bformat(_("The file %1$s cannot be written because it "
                                "is marked as read-only."), file));
                        return false;
                }
        }

        // ask if the disk file has been externally modified (use checksum method)
        if (fileName().exists() && isChecksumModified()) {
                docstring text =
                        bformat(_("Document %1$s has been externally modified. "
                                "Are you sure you want to overwrite this file?"), file);
                int const ret = Alert::prompt(_("Overwrite modified file?"),
                        text, 1, 1, _("&Overwrite"), _("&Cancel"));
                if (ret == 1)
                        return false;
        }

        // We don't need autosaves in the immediate future. (Asger)
        resetAutosaveTimers();

        // if the file does not yet exist, none of the backup activity
        // that follows is necessary
        if (!fileName().exists()) {
                if (!writeFile(fileName()))
                        return false;
                markClean();
                return true;
        }

        // we first write the file to a new name, then move it to its
        // proper location once that has been done successfully. that
        // way we preserve the original file if something goes wrong.
        string const justname = fileName().onlyFileNameWithoutExt();
        auto tempfile = lyx::make_unique<TempFile>(fileName().onlyPath(),
                                              justname + "-XXXXXX.lyx");
        bool const symlink = fileName().isSymLink();
        if (!symlink)
                tempfile->setAutoRemove(false);

        FileName savefile(tempfile->name());
        LYXERR(Debug::FILES, "Saving to " << savefile.absFileName());
        if (!savefile.clonePermissions(fileName()))
                LYXERR0("Failed to clone the permission from " << fileName().absFileName() << " to " << savefile.absFileName());

        if (!writeFile(savefile))
                return false;

        // we will set this to false if we fail
        bool made_backup = true;

        FileName backupName;
        bool const needBackup = lyxrc.make_backup || d->need_format_backup;
        if (needBackup) {
                if (d->need_format_backup)
                        backupName = getBackupName();

                // If we for some reason failed to find a backup name in case of
                // a format change, this will still set one. It's the best we can
                // do in this case.
                if (backupName.empty()) {
                        backupName.set(fileName().absFileName() + "~");
                        if (!lyxrc.backupdir_path.empty()) {
                                string const mangledName =
                                        subst(subst(backupName.absFileName(), '/', '!'), ':', '!');
                                backupName.set(addName(lyxrc.backupdir_path, mangledName));
                        }
                }

                LYXERR(Debug::FILES, "Backing up original file to " <<
                                backupName.absFileName());
                // Except file is symlink do not copy because of #6587.
                // Hard links have bad luck.
                made_backup = symlink ?
                        fileName().copyTo(backupName):
                        fileName().moveTo(backupName);

                if (!made_backup) {
                        Alert::error(_("Backup failure"),
                                     bformat(_("Cannot create backup file %1$s.\n"
                                               "Please check whether the directory exists and is writable."),
                                             from_utf8(backupName.absFileName())));
                        //LYXERR(Debug::DEBUG, "Fs error: " << fe.what());
                } else if (d->need_format_backup) {
                        // the original file has been backed up successfully, so we
                        // will not need to do that again
                        d->need_format_backup = false;
                }
        }

        // Destroy tempfile since it keeps the file locked on windows (bug 9234)
        // Only do this if tempfile is not in autoremove mode
        if (!symlink)
                tempfile.reset();
        // If we have no symlink, we can simply rename the temp file.
        // Otherwise, we need to copy it so the symlink stays intact.
        if (made_backup && symlink ? savefile.copyTo(fileName(), true) :
                                           savefile.moveTo(fileName()))
        {
                // saveCheckSum() was already called by writeFile(), but the
                // time stamp is invalidated by copying/moving
                saveCheckSum();
                markClean();
                // the file associated with this buffer is now in the current format
                d->file_format = LYX_FORMAT;
                return true;
        }
        // else we saved the file, but failed to move it to the right location.

        if (needBackup && made_backup && !symlink) {
                // the original file was moved to some new location, so it will look
                // to the user as if it was deleted. (see bug #9234.) we could try
                // to restore it, but that would basically mean trying to do again
                // what we just failed to do. better to leave things as they are.
                Alert::error(_("Write failure"),
                             bformat(_("The file has successfully been saved as:\n  %1$s.\n"
                                       "But LyX could not move it to:\n  %2$s.\n"
                                       "Your original file has been backed up to:\n  %3$s"),
                                     from_utf8(savefile.absFileName()),
                                     from_utf8(fileName().absFileName()),
                                     from_utf8(backupName.absFileName())));
        } else {
                // either we did not try to make a backup, or else we tried and failed,
                // or else the original file was a symlink, in which case it was copied,
                // not moved. so the original file is intact.
                Alert::error(_("Write failure"),
                             bformat(_("Cannot move saved file to:\n  %1$s.\n"
                                       "But the file has successfully been saved as:\n  %2$s."),
                                     from_utf8(fileName().absFileName()),
                         from_utf8(savefile.absFileName())));
        }
        return false;
}


bool Buffer::writeFile(FileName const & fname) const
{
        if (d->read_only && fname == d->filename)
                return false;

        bool retval = false;

        docstring const str = bformat(_("Saving document %1$s..."),
                makeDisplayPath(fname.absFileName()));
        message(str);

        string const encoded_fname = fname.toSafeFilesystemEncoding(os::CREATE);

        if (params().compressed) {
                gz::ogzstream ofs(encoded_fname.c_str(), ios::out|ios::trunc);
                retval = ofs && write(ofs);
        } else {
                ofstream ofs(encoded_fname.c_str(), ios::out|ios::trunc);
                retval = ofs && write(ofs);
        }

        if (!retval) {
                message(str + _(" could not write file!"));
                return false;
        }

        // see bug 6587
        // removeAutosaveFile();

        saveCheckSum();
        message(str + _(" done."));

        return true;
}


docstring Buffer::emergencyWrite() const
{
        // No need to save if the buffer has not changed.
        if (isClean())
                return docstring();

        string const doc = isUnnamed() ? onlyFileName(absFileName()) : absFileName();

        docstring user_message = bformat(
                _("LyX: Attempting to save document %1$s\n"), from_utf8(doc));

        // We try to save three places:
        // 1) Same place as document. Unless it is an unnamed doc.
        if (!isUnnamed()) {
                string s = absFileName();
                s += ".emergency";
                LYXERR0("  " << s);
                if (writeFile(FileName(s))) {
                        markClean();
                        user_message += "  " + bformat(_("Saved to %1$s. Phew.\n"), from_utf8(s));
                        return user_message;
                } else {
                        user_message += "  " + _("Save failed! Trying again...\n");
                }
        }

        // 2) In HOME directory.
        string s = addName(Package::get_home_dir().absFileName(), absFileName());
        s += ".emergency";
        lyxerr << ' ' << s << endl;
        if (writeFile(FileName(s))) {
                markClean();
                user_message += "  " + bformat(_("Saved to %1$s. Phew.\n"), from_utf8(s));
                return user_message;
        }

        user_message += "  " + _("Save failed! Trying yet again...\n");

        // 3) In "/tmp" directory.
        // MakeAbsPath to prepend the current
        // drive letter on OS/2
        s = addName(package().temp_dir().absFileName(), absFileName());
        s += ".emergency";
        lyxerr << ' ' << s << endl;
        if (writeFile(FileName(s))) {
                markClean();
                user_message += "  " + bformat(_("Saved to %1$s. Phew.\n"), from_utf8(s));
                return user_message;
        }

        user_message += "  " + _("Save failed! Document is lost.");
        // Don't try again.
        markClean();
        return user_message;
}


bool Buffer::write(ostream & ofs) const
{
#ifdef HAVE_LOCALE
        // Use the standard "C" locale for file output.
        ofs.imbue(locale::classic());
#endif

        // The top of the file should not be written by params().

        // write out a comment in the top of the file
        // Important: Keep the version formatting in sync with lyx2lyx and
        //            tex2lyx (bug 7951)
        ofs << "#LyX " << lyx_version_major << "." << lyx_version_minor
            << " created this file. For more info see https://www.lyx.org/\n"
            << "\\lyxformat " << LYX_FORMAT << "\n"
            << "\\begin_document\n";

        /// For each author, set 'used' to true if there is a change
        /// by this author in the document; otherwise set it to 'false'.
        for (Author const & a : params().authors())
                a.setUsed(false);

        ParIterator const end = const_cast<Buffer *>(this)->par_iterator_end();
        ParIterator it = const_cast<Buffer *>(this)->par_iterator_begin();
        for ( ; it != end; ++it)
                it->checkAuthors(params().authors());

        // now write out the buffer parameters.
        ofs << "\\begin_header\n";
        params().writeFile(ofs, this);
        ofs << "\\end_header\n";

        // write the text
        ofs << "\n\\begin_body\n";
        text().write(ofs);
        ofs << "\n\\end_body\n";

        // Write marker that shows file is complete
        ofs << "\\end_document" << endl;

        // Shouldn't really be needed....
        //ofs.close();

        // how to check if close went ok?
        // Following is an attempt... (BE 20001011)

        // good() returns false if any error occurred, including some
        //        formatting error.
        // bad()  returns true if something bad happened in the buffer,
        //        which should include file system full errors.

        bool status = true;
        if (!ofs) {
                status = false;
                lyxerr << "File was not closed properly." << endl;
        }

        return status;
}


Buffer::ExportStatus Buffer::makeLaTeXFile(FileName const & fname,
                           string const & original_path,
                           OutputParams const & runparams_in,
                           OutputWhat output) const
{
        OutputParams runparams = runparams_in;

        string const encoding = runparams.encoding->iconvName();
        LYXERR(Debug::OUTFILE, "makeLaTeXFile encoding: " << encoding << ", fname=" << fname.realPath());

        ofdocstream ofs;
        try { ofs.reset(encoding); }
        catch (iconv_codecvt_facet_exception const & e) {
                lyxerr << "Caught iconv exception: " << e.what() << endl;
                Alert::error(_("Iconv software exception Detected"),
                        bformat(_("Please verify that the `iconv' support software is"
                                          " properly installed and supports the selected encoding"
                                          " (%1$s), or change the encoding in"
                                          " Document>Settings>Language."), from_ascii(encoding)));
                return ExportError;
        }
        if (!openFileWrite(ofs, fname))
                return ExportError;

        ErrorList & errorList = d->errorLists["Export"];
        errorList.clear();
        ExportStatus status = ExportSuccess;
        otexstream os(ofs);

        // make sure we are ready to export
        // this needs to be done before we validate
        // FIXME Do we need to do this all the time? I.e., in children
        // of a master we are exporting?
        updateBuffer();
        updateMacroInstances(OutputUpdate);

        ExportStatus retval;
        try {
                retval = writeLaTeXSource(os, original_path, runparams, output);
                if (retval == ExportKilled)
                        return ExportKilled;
        }
        catch (EncodingException const & e) {
                docstring const failed(1, e.failed_char);
                ostringstream oss;
                oss << "0x" << hex << static_cast<uint32_t>(e.failed_char) << dec;
                if (getParFromID(e.par_id).paragraph().layout().pass_thru) {
                        docstring msg = bformat(_("Uncodable character '%1$s'"
                                                  " (code point %2$s)"),
                                                  failed, from_utf8(oss.str()));
                        errorList.push_back(ErrorItem(msg, _("Some characters of your document are not "
                                        "representable in specific verbatim contexts.\n"
                                        "Changing the document encoding to utf8 could help."),
                                                      {e.par_id, e.pos}, {e.par_id, e.pos + 1}));
                } else {
                        docstring msg = bformat(_("Could not find LaTeX command for character '%1$s'"
                                                  " (code point %2$s)"),
                                                  failed, from_utf8(oss.str()));
                        errorList.push_back(ErrorItem(msg, _("Some characters of your document are probably not "
                                        "representable in the chosen encoding.\n"
                                        "Changing the document encoding to utf8 could help."),
                                                      {e.par_id, e.pos}, {e.par_id, e.pos + 1}));
                }
                status = ExportError;
        }
        catch (iconv_codecvt_facet_exception const & e) {
                errorList.push_back(ErrorItem(_("iconv conversion failed"),
                                              _(e.what())));
                status = ExportError;
        }
        catch (exception const & e) {
                errorList.push_back(ErrorItem(_("conversion failed"),
                                              _(e.what())));
                lyxerr << e.what() << endl;
                status = ExportError;
        }
        catch (...) {
                lyxerr << "Caught some really weird exception..." << endl;
                lyx_exit(1);
        }

        d->texrow = std::move(os.texrow());

        ofs.close();
        if (ofs.fail()) {
                status = ExportError;
                lyxerr << "File '" << fname << "' was not closed properly." << endl;
        }

        if (runparams_in.silent)
                errorList.clear();
        else
                errors("Export");
        return status;
}


Buffer::ExportStatus Buffer::writeLaTeXSource(otexstream & os,
                           string const & original_path,
                           OutputParams const & runparams_in,
                           OutputWhat output) const
{
        // The child documents, if any, shall be already loaded at this point.

        OutputParams runparams = runparams_in;

        // Some macros rely on font encoding
        runparams.main_fontenc = params().main_font_encoding();

        // If we are compiling a file standalone, even if this is the
        // child of some other buffer, let's cut the link here, so the
        // file is really independent and no concurring settings from
        // the master (e.g. branch state) interfere (see #8100).
        if (!runparams.is_child)
                d->ignore_parent = true;

        // Classify the unicode characters appearing in math insets
        BufferEncodings::initUnicodeMath(*this);

        // validate the buffer.
        LYXERR(Debug::OUTFILE, "  Validating buffer...");
        LaTeXFeatures features(*this, params(), runparams);
        validate(features);
        // This is only set once per document (in master)
        if (!runparams.is_child) {
                runparams.use_polyglossia = features.usePolyglossia();
                runparams.use_hyperref = features.isRequired("hyperref");
                runparams.use_CJK = features.mustProvide("CJK");
        }
        LYXERR(Debug::OUTFILE, "  Buffer validation done.");

        bool const output_preamble =
                output == FullSource || output == OnlyPreamble;
        bool const output_body =
                output == FullSource || output == OnlyBody;

        // The starting paragraph of the coming rows is the
        // first paragraph of the document. (Asger)
        if (output_preamble && runparams.nice) {
                os << "%% LyX " << lyx_version << " created this file.  "
                        "For more info, see https://www.lyx.org/.\n"
                        "%% Do not edit unless you really know what "
                        "you are doing.\n";
        }
        LYXERR(Debug::INFO, "lyx document header finished");

        // There are a few differences between nice LaTeX and usual files:
        // usual files have \batchmode and special input@path to allow
        // inclusion of figures specified by an explicitly relative path
        // (i.e., a path starting with './' or '../') with either \input or
        // \includegraphics, as the TEXINPUTS method doesn't work in this case.
        // input@path is set when the actual parameter original_path is set.
        // This is done for usual tex-file, but not for nice-latex-file.
        // (Matthias 250696)
        // Note that input@path is only needed for something the user does
        // in the preamble, included .tex files or ERT, files included by
        // LyX work without it.
        if (output_preamble) {
                if (!runparams.nice) {
                        // code for usual, NOT nice-latex-file
                        os << "\\batchmode\n"; // changed from \nonstopmode
                }
                if (!original_path.empty()) {
                        // FIXME UNICODE
                        // We don't know the encoding of inputpath
                        docstring const inputpath = from_utf8(original_path);
                        docstring uncodable_glyphs;
                        Encoding const * const enc = runparams.encoding;
                        if (enc) {
                                for (char_type n : inputpath) {
                                        if (!enc->encodable(n)) {
                                                docstring const glyph(1, n);
                                                LYXERR0("Uncodable character '"
                                                        << glyph
                                                        << "' in input path!");
                                                uncodable_glyphs += glyph;
                                        }
                                }
                        }

                        // warn user if we found uncodable glyphs.
                        if (!uncodable_glyphs.empty()) {
                                frontend::Alert::warning(
                                        _("Uncodable character in file path"),
                                        bformat(
                                          _("The path of your document\n"
                                            "(%1$s)\n"
                                            "contains glyphs that are unknown "
                                            "in the current document encoding "
                                            "(namely %2$s). This may result in "
                                            "incomplete output, unless "
                                            "TEXINPUTS contains the document "
                                            "directory and you don't use "
                                            "explicitly relative paths (i.e., "
                                            "paths starting with './' or "
                                            "'../') in the preamble or in ERT."
                                            "\n\nIn case of problems, choose "
                                            "an appropriate document encoding\n"
                                            "(such as utf8) or change the "
                                            "file path name."),
                                          inputpath, uncodable_glyphs));
                        } else {
                                string docdir = os::latex_path(original_path);
                                if (contains(docdir, '#')) {
                                        docdir = subst(docdir, "#", "\\#");
                                        os << "\\catcode`\\#=11"
                                              "\\def\\#{#}\\catcode`\\#=6\n";
                                }
                                if (contains(docdir, '%')) {
                                        docdir = subst(docdir, "%", "\\%");
                                        os << "\\catcode`\\%=11"
                                              "\\def\\%{%}\\catcode`\\%=14\n";
                                }
                                if (contains(docdir, '~'))
                                        docdir = subst(docdir, "~", "\\string~");
                                bool const nonascii = !isAscii(from_utf8(docdir));
                                // LaTeX 2019/10/01 handles non-ascii path without detokenize
                                bool const utfpathlatex = features.isAvailableAtLeastFrom("LaTeX", 2019, 10);
                                bool const detokenize = !utfpathlatex && nonascii;
                                bool const quote = contains(docdir, ' ');
                                if (utfpathlatex && nonascii)
                                        os << "\\UseRawInputEncoding\n";
                                os << "\\makeatletter\n"
                                   << "\\def\\input@path{{";
                                if (detokenize)
                                        os << "\\detokenize{";
                                if (quote)
                                        os << "\"";
                                os << docdir;
                                if (quote)
                                        os << "\"";
                                if (detokenize)
                                        os << "}";
                                os << "}}\n"
                                   << "\\makeatother\n";
                        }
                }

                // get parent macros (if this buffer has a parent) which will be
                // written at the document begin further down.
                MacroSet parentMacros;
                listParentMacros(parentMacros, features);

                // Write the preamble
                runparams.use_babel = params().writeLaTeX(os, features,
                                                          d->filename.onlyPath());

                // Active characters
                runparams.active_chars = features.getActiveChars();

                // Biblatex bibliographies are loaded here
                if (params().useBiblatex()) {
                        vector<pair<docstring, string>> const bibfiles =
                                prepareBibFilePaths(runparams, getBibfiles(), true);
                        for (pair<docstring, string> const & file: bibfiles) {
                                os << "\\addbibresource";
                                if (!file.second.empty())
                                        os << "[bibencoding=" << file.second << "]";
                                os << "{" << file.first << "}\n";
                        }
                }

                if (!runparams.dryrun && features.hasPolyglossiaExclusiveLanguages()
                    && !features.hasOnlyPolyglossiaLanguages()) {
                        docstring blangs;
                        docstring plangs;
                        vector<string> bll = features.getBabelExclusiveLanguages();
                        vector<string> pll = features.getPolyglossiaExclusiveLanguages();
                        if (!bll.empty()) {
                                docstring langs;
                                for (string const & sit : bll) {
                                        if (!langs.empty())
                                                langs += ", ";
                                        langs += _(sit);
                                }
                                blangs = bll.size() > 1 ?
                                            bformat(_("The languages %1$s are only supported by Babel."), langs)
                                          : bformat(_("The language %1$s is only supported by Babel."), langs);
                        }
                        if (!pll.empty()) {
                                docstring langs;
                                for (string const & pit : pll) {
                                        if (!langs.empty())
                                                langs += ", ";
                                        langs += _(pit);
                                }
                                plangs = pll.size() > 1 ?
                                            bformat(_("The languages %1$s are only supported by Polyglossia."), langs)
                                          : bformat(_("The language %1$s is only supported by Polyglossia."), langs);
                                if (!blangs.empty())
                                        plangs += "\n";
                        }

                        frontend::Alert::warning(
                                _("Incompatible Languages!"),
                                bformat(
                                  _("You cannot use the following languages "
                                    "together in one LaTeX document because "
                                    "they require conflicting language packages:\n"
                                    "%1$s%2$s"),
                                  plangs, blangs));
                }

                // Japanese might be required only in some children of a document,
                // but once required, we must keep use_japanese true.
                runparams.use_japanese |= features.isRequired("japanese");

                if (!output_body) {
                        // Restore the parenthood if needed
                        if (!runparams.is_child)
                                d->ignore_parent = false;
                        return ExportSuccess;
                }

                // make the body.
                // mark the beginning of the body to separate it from InPreamble insets
                os.texrow().start(TexRow::beginDocument());
                os << "\\begin{document}\n";

                // mark the start of a new paragraph by simulating a newline,
                // so that os.afterParbreak() returns true at document start
                os.lastChar('\n');

                // output the parent macros
                for (auto const & mac : parentMacros) {
                        int num_lines = mac->write(os.os(), true);
                        os.texrow().newlines(num_lines);
                }

        } // output_preamble

        LYXERR(Debug::INFO, "preamble finished, now the body.");

        // the real stuff
        try {
                latexParagraphs(*this, text(), os, runparams);
        }
        catch (ConversionException const &) { return ExportKilled; }

        // Restore the parenthood if needed
        if (!runparams.is_child)
                d->ignore_parent = false;

        // add this just in case after all the paragraphs
        os << endl;

        if (output_preamble) {
                os << "\\end{document}\n";
                LYXERR(Debug::OUTFILE, "makeLaTeXFile...done");
        } else {
                LYXERR(Debug::OUTFILE, "LaTeXFile for inclusion made.");
        }
        runparams_in.encoding = runparams.encoding;

        LYXERR(Debug::INFO, "Finished making LaTeX file.");
        LYXERR(Debug::INFO, "Row count was " << os.texrow().rows() - 1 << '.');
        return ExportSuccess;
}


Buffer::ExportStatus Buffer::makeDocBookFile(FileName const & fname,
                              OutputParams const & runparams,
                              OutputWhat output) const
{
        LYXERR(Debug::OUTFILE, "makeDocBookFile...");

        ofdocstream ofs;
        if (!openFileWrite(ofs, fname))
                return ExportError;

        // make sure we are ready to export
        // this needs to be done before we validate
        updateBuffer();
        updateMacroInstances(OutputUpdate);

        ExportStatus const retval = writeDocBookSource(ofs, runparams, output);
        if (retval == ExportKilled)
                return ExportKilled;

        ofs.close();
        if (ofs.fail())
                lyxerr << "File '" << fname << "' was not closed properly." << endl;
        return ExportSuccess;
}


Buffer::ExportStatus Buffer::writeDocBookSource(odocstream & os,
                             OutputParams const & runparams,
                             OutputWhat output) const
{
        LaTeXFeatures features(*this, params(), runparams);
        validate(features);
        d->bibinfo_.makeCitationLabels(*this);

        d->texrow.reset();

        DocumentClass const & tclass = params().documentClass();

        bool const output_preamble =
                output == FullSource || output == OnlyPreamble;
        bool const output_body =
                output == FullSource || output == OnlyBody || output == IncludedFile;

        if (output_preamble) {
                // XML preamble, no doctype needed.
                // Not using XMLStream for this, as the root tag would be in the tag stack and make troubles with the error
                // detection mechanisms (these are called before the end tag is output, and thus interact with the canary
                // parsep in output_docbook.cpp).
                os << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
                   << "<!-- This DocBook file was created by LyX " << lyx_version
                   << "\n  See https://www.lyx.org/ for more information -->\n";

                // Prepare the name space declaration for MathML depending on document preferences.
                string mathmlNamespace;
                if (params().docbook_mathml_prefix != BufferParams::NoPrefix) {
                        string mathmlPrefix;
                        if (params().docbook_mathml_prefix == BufferParams::MPrefix)
                                mathmlPrefix = "m";
                        else if (params().docbook_mathml_prefix == BufferParams::MMLPrefix)
                                mathmlPrefix = "mml";
                        mathmlNamespace = + " xmlns:" + mathmlPrefix + "=\"http://www.w3.org/1998/Math/MathML\"";
                }

                // Directly output the root tag, based on the current type of document.
                string languageCode = params().language->code();
                string params = "xml:lang=\"" + languageCode + '"'
                                                + " xmlns=\"http://docbook.org/ns/docbook\""
                                                + " xmlns:xlink=\"http://www.w3.org/1999/xlink\""
                                                + mathmlNamespace
                                                + " xmlns:xi=\"http://www.w3.org/2001/XInclude\""
                                                + " version=\"5.2\"";

                os << "<" << from_ascii(tclass.docbookroot()) << " " << from_ascii(params) << ">\n";
        }

        if (output_body) {
                // Start to output the document.
                XMLStream xs(os);
                docbookParagraphs(text(), *this, xs, runparams);
        }

        if (output_preamble) {
                // Close the root element. No need for a line break, as free text is never allowed
                // in a root element, it must always be wrapped in some container.
                os << "</" << from_ascii(tclass.docbookroot()) << ">";
        }

        return ExportSuccess;
}


Buffer::ExportStatus Buffer::makeLyXHTMLFile(FileName const & fname,
                              OutputParams const & runparams) const
{
        LYXERR(Debug::OUTFILE, "makeLyXHTMLFile...");

        ofdocstream ofs;
        if (!openFileWrite(ofs, fname))
                return ExportError;

        // make sure we are ready to export
        // this has to be done before we validate
        updateBuffer(UpdateMaster, OutputUpdate);
        updateMacroInstances(OutputUpdate);

        ExportStatus const retval = writeLyXHTMLSource(ofs, runparams, FullSource);
        if (retval == ExportKilled)
                return retval;

        ofs.close();
        if (ofs.fail())
                lyxerr << "File '" << fname << "' was not closed properly." << endl;
        return retval;
}


Buffer::ExportStatus Buffer::writeLyXHTMLSource(odocstream & os,
                             OutputParams const & runparams,
                             OutputWhat output) const
{
        LaTeXFeatures features(*this, params(), runparams);
        validate(features);
        d->bibinfo_.makeCitationLabels(*this);

        bool const output_preamble =
                output == FullSource || output == OnlyPreamble;
        bool const output_body =
          output == FullSource || output == OnlyBody || output == IncludedFile;

        if (output_preamble) {
                os << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
                   << "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN\" \"http://www.w3.org/Math/DTD/mathml2/xhtml-math11-f.dtd\">\n"
                   // FIXME Language should be set properly.
                   << "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n"
                   << "<head>\n"
                   << "<meta name=\"GENERATOR\" content=\"" << PACKAGE_STRING << "\" />\n"
                   // FIXME Presumably need to set this right
                   << "<meta http-equiv=\"Content-type\" content=\"text/html;charset=UTF-8\" />\n";

                docstring const & doctitle = features.htmlTitle();
                os << "<title>"
                   << (doctitle.empty() ?
                         from_ascii("LyX Document") :
                         xml::escapeString(doctitle, XMLStream::ESCAPE_ALL))
                   << "</title>\n";

                docstring styles = features.getTClassHTMLPreamble();
                if (!styles.empty())
                        os << "\n<!-- Text Class Preamble -->\n" << styles << '\n';

                // we will collect CSS information in a stream, and then output it
                // either here, as part of the header, or else in a separate file.
                odocstringstream css;
                styles = features.getCSSSnippets();
                if (!styles.empty())
                        css << "/* LyX Provided Styles */\n" << styles << '\n';

                styles = features.getTClassHTMLStyles();
                if (!styles.empty())
                        css << "/* Layout-provided Styles */\n" << styles << '\n';

                bool const needfg = params().fontcolor != RGBColor(0, 0, 0);
                bool const needbg = params().backgroundcolor != RGBColor(0xFF, 0xFF, 0xFF);
                if (needfg || needbg) {
                                css << "\nbody {\n";
                                if (needfg)
                                   css << "  color: "
                                            << from_ascii(X11hexname(params().fontcolor))
                                            << ";\n";
                                if (needbg)
                                   css << "  background-color: "
                                            << from_ascii(X11hexname(params().backgroundcolor))
                                            << ";\n";
                                css << "}\n";
                }

                docstring const dstyles = css.str();
                if (!dstyles.empty()) {
                        bool written = false;
                        if (params().html_css_as_file) {
                                // open a file for CSS info
                                ofdocstream ocss;
                                string const fcssname = addName(temppath(), "docstyle.css");
                                FileName const fcssfile = FileName(fcssname);
                                if (openFileWrite(ocss, fcssfile)) {
                                        ocss << dstyles;
                                        ocss.close();
                                        written = true;
                                        // write link to header
                                        os << "<link rel='stylesheet' href='docstyle.css' type='text/css' />\n";
                                        // register file
                                        runparams.exportdata->addExternalFile("xhtml", fcssfile);
                                }
                        }
                        // we are here if the CSS is supposed to be written to the header
                        // or if we failed to write it to an external file.
                        if (!written) {
                                os << "<style type='text/css'>\n"
                                         << dstyles
                                         << "\n</style>\n";
                        }
                }
                os << "</head>\n";
        }

        if (output_body) {
                bool const output_body_tag = (output != IncludedFile);
                if (output_body_tag)
                        os << "<body dir=\"auto\">\n";
                XMLStream xs(os);
                if (output != IncludedFile)
                        // if we're an included file, the counters are in the master.
                        params().documentClass().counters().reset();
                try {
                        xhtmlParagraphs(text(), *this, xs, runparams);
                }
                catch (ConversionException const &) { return ExportKilled; }
                if (output_body_tag)
                        os << "</body>\n";
        }

        if (output_preamble)
                os << "</html>\n";

        return ExportSuccess;
}


// chktex should be run with these flags disabled: 3, 22, 25, 30, 38(?)
// Other flags: -wall -v0 -x
int Buffer::runChktex()
{
        setBusy(true);

        // get LaTeX-Filename
        FileName const path(temppath());
        string const name = addName(path.absFileName(), latexName());
        string const org_path = filePath();

        PathChanger p(path); // path to LaTeX file
        message(_("Running chktex..."));

        // Generate the LaTeX file if neccessary
        OutputParams runparams(&params().encoding());
        runparams.flavor = Flavor::LaTeX;
        runparams.nice = false;
        runparams.linelen = lyxrc.plaintext_linelen;
        ExportStatus const retval =
                makeLaTeXFile(FileName(name), org_path, runparams);
        if (retval != ExportSuccess) {
                // error code on failure
                return -1;
        }

        TeXErrors terr;
        Chktex chktex(lyxrc.chktex_command, onlyFileName(name), filePath());
        int const res = chktex.run(terr); // run chktex

        if (res == -1) {
                Alert::error(_("chktex failure"),
                             _("Could not run chktex successfully."));
        } else {
                ErrorList & errlist = d->errorLists["ChkTeX"];
                errlist.clear();
                bufferErrors(terr, errlist);
        }

        setBusy(false);

        if (runparams.silent)
                d->errorLists["ChkTeX"].clear();
        else
                errors("ChkTeX");

        return res;
}


void Buffer::validate(LaTeXFeatures & features) const
{
        // Validate the buffer params, but not for included
        // files, since they also use the parent buffer's
        // params (# 5941)
        if (!features.runparams().is_child)
                params().validate(features);

        if (!parent())
                clearIncludeList();

        for (Paragraph const & p : paragraphs())
                p.validate(features);

        if (lyxerr.debugging(Debug::OUTFILE)) {
                features.showStruct();
        }
}


void Buffer::getLabelList(vector<std::pair<docstring, docstring>> & list) const
{
        // If this is a child document, use the master's list instead.
        if (parent()) {
                masterBuffer()->getLabelList(list);
                return;
        }

        list.clear();
        shared_ptr<Toc> toc = d->toc_backend.toc("label");
        for (auto const & tocit : *toc) {
                if (tocit.depth() == 0)
                        list.push_back(make_pair(tocit.str(), tocit.asString()));
        }
}


void Buffer::invalidateBibinfoCache() const
{
        d->bibinfo_cache_valid_ = false;
        d->cite_labels_valid_ = false;
        removeBiblioTempFiles();
        // also invalidate the cache for the parent buffer
        Buffer const * const pbuf = d->parent();
        if (pbuf)
                pbuf->invalidateBibinfoCache();
}


docstring_list const & Buffer::getBibfiles(UpdateScope scope) const
{
        // FIXME This is probably unnecessary, given where we call this.
        // If this is a child document, use the master instead.
        Buffer const * const pbuf = masterBuffer();
        if (pbuf != this && scope != UpdateChildOnly)
                return pbuf->getBibfiles();

        // In 2.3.x, we have:
        //if (!d->bibfile_cache_valid_)
        //      this->updateBibfilesCache(scope);
        // I think that is a leftover, but there have been so many back-
        // and-forths with this, due to Windows issues, that I am not sure.

        return d->bibfiles_cache_;
}


BiblioInfo const & Buffer::masterBibInfo() const
{
        Buffer const * const tmp = masterBuffer();
        if (tmp != this)
                return tmp->masterBibInfo();
        return d->bibinfo_;
}


BiblioInfo const & Buffer::bibInfo() const
{
        return d->bibinfo_;
}


void Buffer::registerBibfiles(const docstring_list & bf) const
{
        // We register the bib files in the master buffer,
        // if there is one, but also in every single buffer,
        // in case a child is compiled alone.
        Buffer const * const tmp = masterBuffer();
        if (tmp != this)
                tmp->registerBibfiles(bf);

        for (auto const & p : bf) {
                docstring_list::const_iterator temp =
                        find(d->bibfiles_cache_.begin(), d->bibfiles_cache_.end(), p);
                if (temp == d->bibfiles_cache_.end())
                        d->bibfiles_cache_.push_back(p);
        }
}


static map<docstring, FileName> bibfileCache;

FileName Buffer::getBibfilePath(docstring const & bibid) const
{
        map<docstring, FileName>::const_iterator it =
                bibfileCache.find(bibid);
        if (it != bibfileCache.end()) {
                // i.e., return bibfileCache[bibid];
                return it->second;
        }

        LYXERR(Debug::FILES, "Reading file location for " << bibid);
        string const texfile = changeExtension(to_utf8(bibid), "bib");
        // we need to check first if this file exists where it's said to be.
        // there's a weird bug that occurs otherwise: if the file is in the
        // Buffer's directory but has the same name as some file that would be
        // found by kpsewhich, then we find the latter, not the former.
        FileName const local_file = makeAbsPath(texfile, filePath());
        FileName file = local_file;
        if (!file.exists()) {
                // there's no need now to check whether the file can be found
                // locally
                file = findtexfile(texfile, "bib", true);
                if (file.empty())
                        file = local_file;
        }
        LYXERR(Debug::FILES, "Found at: " << file);

        bibfileCache[bibid] = file;
        return bibfileCache[bibid];
}


void Buffer::checkIfBibInfoCacheIsValid() const
{
        // use the master's cache
        Buffer const * const tmp = masterBuffer();
        if (tmp != this) {
                tmp->checkIfBibInfoCacheIsValid();
                return;
        }

        // If we already know the cache is invalid, stop here.
        // This is important in the case when the bibliography
        // environment (rather than Bib[la]TeX) is used.
        // In that case, the timestamp check below gives no
        // sensible result. Rather than that, the cache will
        // be invalidated explicitly via invalidateBibInfoCache()
        // by the Bibitem inset.
        // Same applies for bib encoding changes, which trigger
        // invalidateBibInfoCache() by InsetBibtex.
        if (!d->bibinfo_cache_valid_)
                return;

        if (d->have_bibitems_) {
                // We have a bibliography environment.
                // Invalidate the bibinfo cache unconditionally.
                // Cite labels will get invalidated by the inset if needed.
                d->bibinfo_cache_valid_ = false;
                return;
        }

        // OK. This is with Bib(la)tex. We'll assume the cache
        // is valid and change this if we find changes in the bibs.
        d->bibinfo_cache_valid_ = true;
        d->cite_labels_valid_ = true;

        // compare the cached timestamps with the actual ones.
        docstring_list const & bibfiles_cache = getBibfiles();
        for (auto const & bf : bibfiles_cache) {
                FileName const fn = getBibfilePath(bf);
                time_t lastw = fn.lastModified();
                time_t prevw = d->bibfile_status_[fn];
                if (lastw != prevw) {
                        d->bibinfo_cache_valid_ = false;
                        d->cite_labels_valid_ = false;
                        d->bibfile_status_[fn] = lastw;
                }
        }
}


void Buffer::clearBibFileCache() const
{
        bibfileCache.clear();
}


void Buffer::reloadBibInfoCache(bool const force) const
{
        // we should not need to do this for internal buffers
        if (isInternal())
                return;

        // use the master's cache
        Buffer const * const tmp = masterBuffer();
        if (tmp != this) {
                tmp->reloadBibInfoCache(force);
                return;
        }

        if (!force) {
                checkIfBibInfoCacheIsValid();
                if (d->bibinfo_cache_valid_)
                        return;
        }

        LYXERR(Debug::FILES, "Bibinfo cache was invalid.");
        // re-read file locations when this info changes
        // FIXME Is this sufficient? Or should we also force that
        // in some other cases? If so, then it is easy enough to
        // add the following line in some other places.
        clearBibFileCache();
        d->bibinfo_.clear();
        FileNameList checkedFiles;
        d->have_bibitems_ = false;
        collectBibKeys(checkedFiles);
        d->bibinfo_cache_valid_ = true;
}


void Buffer::collectBibKeys(FileNameList & checkedFiles) const
{
        if (!parent())
                clearIncludeList();

        for (InsetIterator it = begin(inset()); it; ++it) {
                it->collectBibKeys(it, checkedFiles);
                if (it->lyxCode() == BIBITEM_CODE) {
                        if (parent() != nullptr)
                                parent()->d->have_bibitems_ = true;
                        else
                                d->have_bibitems_ = true;
                }
        }
}


void Buffer::addBiblioInfo(BiblioInfo const & bi_in) const
{
        // We add the biblio info to the parent buffer,
        // if there is one, but also to this buffer, in case
        // it is compiled alone.
        BiblioInfo & our_bi = d->bibinfo_;
        our_bi.mergeBiblioInfo(bi_in);

        if (parent())
                parent()->addBiblioInfo(bi_in);
}


void Buffer::addBibTeXInfo(docstring const & key, BibTeXInfo const & bin) const
{
        // We add the bibtex info to the master buffer,
        // if there is one, but also to every single buffer,
        // in case a child is compiled alone.
        BiblioInfo & bi = d->bibinfo_;
        bi[key] = bin;

        if (parent() != nullptr) {
                BiblioInfo & masterbi = masterBuffer()->d->bibinfo_;
                masterbi[key] = bin;
        }
}


void Buffer::makeCitationLabels() const
{
        Buffer const * const master = masterBuffer();
        return d->bibinfo_.makeCitationLabels(*master);
}


void Buffer::invalidateCiteLabels() const
{
        masterBuffer()->d->cite_labels_valid_ = false;
}

bool Buffer::citeLabelsValid() const
{
        return masterBuffer()->d->cite_labels_valid_;
}


void Buffer::removeBiblioTempFiles() const
{
        // We remove files that contain LaTeX commands specific to the
        // particular bibliographic style being used, in order to avoid
        // LaTeX errors when we switch style.
        FileName const aux_file(addName(temppath(), changeExtension(latexName(),".aux")));
        FileName const bbl_file(addName(temppath(), changeExtension(latexName(),".bbl")));
        LYXERR(Debug::FILES, "Removing the .aux file " << aux_file);
        aux_file.removeFile();
        LYXERR(Debug::FILES, "Removing the .bbl file " << bbl_file);
        bbl_file.removeFile();
        // Also for the parent buffer
        Buffer const * const pbuf = parent();
        if (pbuf)
                pbuf->removeBiblioTempFiles();
}


bool Buffer::isDepClean(string const & name) const
{
        DepClean::const_iterator const it = d->dep_clean.find(name);
        if (it == d->dep_clean.end())
                return true;
        return it->second;
}


void Buffer::markDepClean(string const & name)
{
        d->dep_clean[name] = true;
}


bool Buffer::getStatus(FuncRequest const & cmd, FuncStatus & flag) const
{
        if (isInternal()) {
                // FIXME? if there is an Buffer LFUN that can be dispatched even
                // if internal, put a switch '(cmd.action)' here.
                return false;
        }

        bool enable = true;

        switch (cmd.action()) {

        case LFUN_BUFFER_TOGGLE_READ_ONLY:
                flag.setOnOff(hasReadonlyFlag());
                break;

                // FIXME: There is need for a command-line import.
                //case LFUN_BUFFER_IMPORT:

        case LFUN_BUFFER_AUTO_SAVE:
                break;

        case LFUN_BUFFER_EXPORT_CUSTOM:
                // FIXME: Nothing to check here?
                break;

        case LFUN_BUFFER_EXPORT: {
                docstring const & arg = cmd.argument();
                if (arg == "custom") {
                        enable = true;
                        break;
                }
                string format = (arg.empty() || arg == "default") ?
                        params().getDefaultOutputFormat() : to_utf8(arg);
                size_t pos = format.find(' ');
                if (pos != string::npos)
                        format = format.substr(0, pos);
                enable = params().isExportable(format, false);
                if (!enable)
                        flag.message(bformat(
                                             _("Don't know how to export to format: %1$s"), arg));
                break;
        }

        case LFUN_BUILD_PROGRAM:
                enable = params().isExportable("program", false);
                break;

        case LFUN_BRANCH_ACTIVATE:
        case LFUN_BRANCH_DEACTIVATE:
        case LFUN_BRANCH_MASTER_ACTIVATE:
        case LFUN_BRANCH_MASTER_DEACTIVATE: {
                bool const master = (cmd.action() == LFUN_BRANCH_MASTER_ACTIVATE
                                     || cmd.action() == LFUN_BRANCH_MASTER_DEACTIVATE);
                BranchList const & branchList = master ? masterBuffer()->params().branchlist()
                        : params().branchlist();
                docstring const & branchName = cmd.argument();
                flag.setEnabled(!branchName.empty() && branchList.find(branchName));
                break;
        }

        case LFUN_BRANCH_ADD:
        case LFUN_BRANCHES_RENAME:
                // if no Buffer is present, then of course we won't be called!
                break;

        case LFUN_BUFFER_LANGUAGE:
                enable = !isReadonly();
                break;

        case LFUN_BUFFER_VIEW_CACHE:
                (d->preview_file_).refresh();
                enable = (d->preview_file_).exists() && !(d->preview_file_).isFileEmpty();
                break;

        case LFUN_CHANGES_TRACK:
                flag.setEnabled(true);
                flag.setOnOff(params().track_changes);
                break;

        case LFUN_CHANGES_OUTPUT:
                flag.setEnabled(true);
                flag.setOnOff(params().output_changes);
                break;

        case LFUN_BUFFER_TOGGLE_COMPRESSION:
                flag.setOnOff(params().compressed);
                break;

        case LFUN_BUFFER_TOGGLE_OUTPUT_SYNC:
                flag.setOnOff(params().output_sync);
                break;

        case LFUN_BUFFER_ANONYMIZE:
                break;

        default:
                return false;
        }
        flag.setEnabled(enable);
        return true;
}


void Buffer::dispatch(string const & command, DispatchResult & result)
{
        return dispatch(lyxaction.lookupFunc(command), result);
}


// NOTE We can end up here even if we have no GUI, because we are called
// by LyX::exec to handled command-line requests. So we may need to check
// whether we have a GUI or not. The boolean use_gui holds this information.
void Buffer::dispatch(FuncRequest const & func, DispatchResult & dr)
{
        if (isInternal()) {
                // FIXME? if there is an Buffer LFUN that can be dispatched even
                // if internal, put a switch '(cmd.action())' here.
                dr.dispatched(false);
                return;
        }
        string const argument = to_utf8(func.argument());
        // We'll set this back to false if need be.
        bool dispatched = true;
        // This handles undo groups automagically
        UndoGroupHelper ugh(this);

        switch (func.action()) {
        case LFUN_BUFFER_TOGGLE_READ_ONLY:
                if (lyxvc().inUse()) {
                        string log = lyxvc().toggleReadOnly();
                        if (!log.empty())
                                dr.setMessage(log);
                }
                else
                        setReadonly(!hasReadonlyFlag());
                break;

        case LFUN_BUFFER_EXPORT: {
                string const format = (argument.empty() || argument == "default") ?
                        params().getDefaultOutputFormat() : argument;
                ExportStatus const status = doExport(format, false);
                dr.setError(status != ExportSuccess);
                if (status != ExportSuccess)
                        dr.setMessage(bformat(_("Error exporting to format: %1$s."),
                                              from_utf8(format)));
                break;
        }

        case LFUN_BUILD_PROGRAM: {
                ExportStatus const status = doExport("program", true);
                dr.setError(status != ExportSuccess);
                if (status != ExportSuccess)
                        dr.setMessage(_("Error generating literate programming code."));
                break;
        }

        case LFUN_BUFFER_EXPORT_CUSTOM: {
                string format_name;
                string command = split(argument, format_name, ' ');
                Format const * format = theFormats().getFormat(format_name);
                if (!format) {
                        lyxerr << "Format \"" << format_name
                                << "\" not recognized!"
                                << endl;
                        break;
                }

                // The name of the file created by the conversion process
                string filename;

                // Output to filename
                if (format->name() == "lyx") {
                        string const latexname = latexName(false);
                        filename = changeExtension(latexname,
                                format->extension());
                        filename = addName(temppath(), filename);

                        if (!writeFile(FileName(filename)))
                                break;

                } else {
                        doExport(format_name, true, filename);
                }

                // Substitute $$FName for filename
                if (!contains(command, "$$FName"))
                        command = "( " + command + " ) < $$FName";
                command = subst(command, "$$FName", filename);

                // Execute the command in the background
                Systemcall call;
                call.startscript(Systemcall::DontWait, command,
                                 filePath(), layoutPos());
                break;
        }

        // FIXME: There is need for a command-line import.
        /*
        case LFUN_BUFFER_IMPORT:
                doImport(argument);
                break;
        */

        case LFUN_BUFFER_AUTO_SAVE:
                autoSave();
                resetAutosaveTimers();
                break;

        case LFUN_BRANCH_ACTIVATE:
        case LFUN_BRANCH_DEACTIVATE:
        case LFUN_BRANCH_MASTER_ACTIVATE:
        case LFUN_BRANCH_MASTER_DEACTIVATE: {
                bool const master = (func.action() == LFUN_BRANCH_MASTER_ACTIVATE
                                     || func.action() == LFUN_BRANCH_MASTER_DEACTIVATE);
                Buffer * buf = master ? const_cast<Buffer *>(masterBuffer())
                                      : this;

                docstring const & branch_name = func.argument();
                // the case without a branch name is handled elsewhere
                if (branch_name.empty()) {
                        dispatched = false;
                        break;
                }
                Branch * branch = buf->params().branchlist().find(branch_name);
                if (!branch) {
                        LYXERR0("Branch " << branch_name << " does not exist.");
                        dr.setError(true);
                        docstring const msg =
                                bformat(_("Branch \"%1$s\" does not exist."), branch_name);
                        dr.setMessage(msg);
                        break;
                }
                bool const activate = (func.action() == LFUN_BRANCH_ACTIVATE
                                       || func.action() == LFUN_BRANCH_MASTER_ACTIVATE);
                if (branch->isSelected() != activate) {
                        buf->undo().recordUndoBufferParams(CursorData());
                        branch->setSelected(activate);
                        dr.setError(false);
                        dr.screenUpdate(Update::Force);
                        dr.forceBufferUpdate();
                }
                break;
        }

        case LFUN_BRANCH_ADD: {
                docstring const & branchnames = func.argument();
                if (branchnames.empty()) {
                        dispatched = false;
                        break;
                }
                BranchList & branch_list = params().branchlist();
                vector<docstring> const branches =
                        getVectorFromString(branchnames, branch_list.separator());
                docstring msg;
                for (docstring const & branch_name : branches) {
                        Branch * branch = branch_list.find(branch_name);
                        if (branch) {
                                LYXERR0("Branch " << branch_name << " already exists.");
                                dr.setError(true);
                                if (!msg.empty())
                                        msg += ("\n");
                                msg += bformat(_("Branch \"%1$s\" already exists."), branch_name);
                        } else {
                                undo().recordUndoBufferParams(CursorData());
                                branch_list.add(branch_name);
                                branch = branch_list.find(branch_name);
                                if (branch)
                                        // needed to update the color table for dark mode
                                        branch->setColors("background", "background");
                                dr.setError(false);
                                dr.screenUpdate(Update::Force);
                        }
                }
                if (!msg.empty())
                        dr.setMessage(msg);
                break;
        }

        case LFUN_BRANCHES_RENAME: {
                if (func.argument().empty())
                        break;

                docstring const oldname = from_utf8(func.getArg(0));
                docstring const newname = from_utf8(func.getArg(1));
                InsetIterator it  = begin(inset());
                InsetIterator const itend = end(inset());
                bool success = false;
                for (; it != itend; ++it) {
                        if (it->lyxCode() == BRANCH_CODE) {
                                InsetBranch & ins = static_cast<InsetBranch &>(*it);
                                if (ins.branch() == oldname) {
                                        undo().recordUndo(CursorData(it));
                                        ins.rename(newname);
                                        success = true;
                                        continue;
                                }
                        }
                        if (it->lyxCode() == INCLUDE_CODE) {
                                // get buffer of external file
                                InsetInclude const & ins =
                                        static_cast<InsetInclude const &>(*it);
                                Buffer * child = ins.loadIfNeeded();
                                if (!child)
                                        continue;
                                child->dispatch(func, dr);
                        }
                }

                if (success) {
                        dr.screenUpdate(Update::Force);
                        dr.forceBufferUpdate();
                }
                break;
        }

        case LFUN_BUFFER_VIEW_CACHE:
                if (!theFormats().view(*this, d->preview_file_,
                                  d->preview_format_))
                        dr.setMessage(_("Error viewing the output file."));
                break;

        case LFUN_CHANGES_TRACK:
                if (params().save_transient_properties)
                        undo().recordUndoBufferParams(CursorData());
                params().track_changes = !params().track_changes;
                break;

        case LFUN_CHANGES_OUTPUT:
                if (params().save_transient_properties)
                        undo().recordUndoBufferParams(CursorData());
                params().output_changes = !params().output_changes;
                if (params().output_changes) {
                        bool xcolorulem = LaTeXFeatures::isAvailable("ulem") &&
                                          LaTeXFeatures::isAvailable("xcolor");

                        if (!xcolorulem) {
                                Alert::warning(_("Changes not shown in LaTeX output"),
                                               _("Changes will not be highlighted in LaTeX output, "
                                                 "because xcolor and ulem are not installed.\n"
                                                 "Please install both packages or redefine "
                                                 "\\lyxadded and \\lyxdeleted in the LaTeX preamble."));
                        }
                }
                break;

        case LFUN_BUFFER_TOGGLE_COMPRESSION:
                // turn compression on/off
                undo().recordUndoBufferParams(CursorData());
                params().compressed = !params().compressed;
                break;

        case LFUN_BUFFER_TOGGLE_OUTPUT_SYNC:
                undo().recordUndoBufferParams(CursorData());
                params().output_sync = !params().output_sync;
                break;

        case LFUN_BUFFER_ANONYMIZE: {
                undo().recordUndoFullBuffer(CursorData());
                CursorData cur(doc_iterator_begin(this));
                for ( ; cur ; cur.forwardPar())
                        cur.paragraph().anonymize();
                dr.forceBufferUpdate();
                dr.screenUpdate(Update::Force);
                break;
        }

        default:
                dispatched = false;
                break;
        }
        dr.dispatched(dispatched);
}


void Buffer::changeLanguage(Language const * from, Language const * to)
{
        LASSERT(from, return);
        LASSERT(to, return);

        ParIterator it = par_iterator_begin();
        ParIterator eit = par_iterator_end();
        for (; it != eit; ++it)
                it->changeLanguage(params(), from, to);
}


bool Buffer::isMultiLingual() const
{
        ParConstIterator end = par_iterator_end();
        for (ParConstIterator it = par_iterator_begin(); it != end; ++it)
                if (it->isMultiLingual(params()))
                        return true;

        return false;
}


std::set<Language const *> Buffer::getLanguages() const
{
        std::set<Language const *> langs;
        getLanguages(langs);
        return langs;
}


void Buffer::getLanguages(std::set<Language const *> & langs) const
{
        ParConstIterator end = par_iterator_end();
        // add the buffer language, even if it's not actively used
        langs.insert(language());
        // iterate over the paragraphs
        for (ParConstIterator it = par_iterator_begin(); it != end; ++it)
                it->getLanguages(langs);
        // also children
        ListOfBuffers clist = getDescendants();
        for (auto const & cit : clist)
                cit->getLanguages(langs);
}


DocIterator Buffer::getParFromID(int const id) const
{
        Buffer * buf = const_cast<Buffer *>(this);
        if (id < 0)
                // This means non-existent
                return doc_iterator_end(buf);

        for (DocIterator it = doc_iterator_begin(buf); !it.atEnd(); it.forwardPar())
                if (it.paragraph().id() == id)
                        return it;

        return doc_iterator_end(buf);
}


bool Buffer::hasParWithID(int const id) const
{
        return !getParFromID(id).atEnd();
}


ParIterator Buffer::par_iterator_begin()
{
        return ParIterator(doc_iterator_begin(this));
}


ParIterator Buffer::par_iterator_end()
{
        return ParIterator(doc_iterator_end(this));
}


ParConstIterator Buffer::par_iterator_begin() const
{
        return ParConstIterator(doc_iterator_begin(this));
}


ParConstIterator Buffer::par_iterator_end() const
{
        return ParConstIterator(doc_iterator_end(this));
}

bool Buffer::empty() const
{
        return paragraphs().size() == 1 && paragraphs().front().empty();
}


Language const * Buffer::language() const
{
        return params().language;
}


docstring Buffer::B_(string const & l10n) const
{
        return params().B_(l10n);
}


bool Buffer::isClean() const
{
        return d->lyx_clean;
}


bool Buffer::isChecksumModified() const
{
        LASSERT(d->filename.exists(), return false);
        return d->checksum_ != d->filename.checksum();
}


void Buffer::saveCheckSum() const
{
        FileName const & file = d->filename;
        file.refresh();
        d->checksum_ = file.exists() ? file.checksum()
                : 0; // in the case of save to a new file.
}


void Buffer::markClean() const
{
        if (!d->lyx_clean) {
                d->lyx_clean = true;
                updateTitles();
        }
        // if the .lyx file has been saved, we don't need an
        // autosave
        d->bak_clean = true;
        d->undo_.markDirty();
        clearExternalModification();
}


void Buffer::setUnnamed(bool flag)
{
        d->unnamed = flag;
}


bool Buffer::isUnnamed() const
{
        return d->unnamed;
}


/// \note
/// Don't check unnamed, here: isInternal() is used in
/// newBuffer(), where the unnamed flag has not been set by anyone
/// yet. Also, for an internal buffer, there should be no need for
/// retrieving fileName() nor for checking if it is unnamed or not.
bool Buffer::isInternal() const
{
        return d->internal_buffer;
}


void Buffer::setInternal(bool flag)
{
        d->internal_buffer = flag;
}


void Buffer::markDirty()
{
        if (d->lyx_clean) {
                d->lyx_clean = false;
                updateTitles();
        }
        d->bak_clean = false;

        for (auto & depit : d->dep_clean)
                depit.second = false;
}


FileName Buffer::fileName() const
{
        return d->filename;
}


string Buffer::absFileName() const
{
        return d->filename.absFileName();
}


string Buffer::filePath() const
{
        string const abs = d->filename.onlyPath().absFileName();
        if (abs.empty())
                return abs;
        int last = abs.length() - 1;

        return abs[last] == '/' ? abs : abs + '/';
}


DocFileName Buffer::getReferencedFileName(string const & fn) const
{
        DocFileName result;
        if (FileName::isAbsolute(fn) || !FileName::isAbsolute(params().origin))
                result.set(fn, filePath());
        else {
                // filePath() ends with a path separator
                FileName const test(filePath() + fn);
                if (test.exists())
                        result.set(fn, filePath());
                else
                        result.set(fn, params().origin);
        }

        return result;
}


string const Buffer::prepareFileNameForLaTeX(string const & name,
                                             string const & ext, bool nice) const
{
        string const fname = makeAbsPath(name, filePath()).absFileName();
        if (FileName::isAbsolute(name) || !FileName(fname + ext).isReadableFile())
                return name;
        if (!nice)
                return fname;

        // FIXME UNICODE
        return to_utf8(makeRelPath(from_utf8(fname),
                from_utf8(masterBuffer()->filePath())));
}


vector<pair<docstring, string>> const Buffer::prepareBibFilePaths(OutputParams const & runparams,
                                                docstring_list const & bibfilelist,
                                                bool const add_extension) const
{
        // If we are processing the LaTeX file in a temp directory then
        // copy the .bib databases to this temp directory, mangling their
        // names in the process. Store this mangled name in the list of
        // all databases.
        // (We need to do all this because BibTeX *really*, *really*
        // can't handle "files with spaces" and Windows users tend to
        // use such filenames.)
        // Otherwise, store the (maybe absolute) path to the original,
        // unmangled database name.

        vector<pair<docstring, string>> res;

        // determine the export format
        string const tex_format = flavor2format(runparams.flavor);

        // check for spaces in paths
        bool found_space = false;

        for (auto const & bit : bibfilelist) {
                string utf8input = to_utf8(bit);
                string database =
                        prepareFileNameForLaTeX(utf8input, ".bib", runparams.nice);
                FileName try_in_file =
                        makeAbsPath(database + ".bib", filePath());
                bool not_from_texmf = try_in_file.isReadableFile();
                // If the file has not been found, try with the real file name
                // (it might come from a child in a sub-directory)
                if (!not_from_texmf) {
                        try_in_file = getBibfilePath(bit);
                        if (try_in_file.isReadableFile()) {
                                // Check if the file is in texmf
                                FileName kpsefile(findtexfile(changeExtension(utf8input, "bib"), "bib", true));
                                not_from_texmf = kpsefile.empty()
                                                || kpsefile.absFileName() != try_in_file.absFileName();
                                if (not_from_texmf)
                                        // If this exists, make path relative to the master
                                        // FIXME Unicode
                                        database =
                                                removeExtension(prepareFileNameForLaTeX(
                                                                                        to_utf8(makeRelPath(from_utf8(try_in_file.absFileName()),
                                                                                                                                from_utf8(filePath()))),
                                                                                        ".bib", runparams.nice));
                        }
                }

                if (!runparams.inComment && !runparams.dryrun && !runparams.nice &&
                    not_from_texmf) {
                        // mangledFileName() needs the extension
                        DocFileName const in_file = DocFileName(try_in_file);
                        database = removeExtension(in_file.mangledFileName());
                        FileName const out_file = makeAbsPath(database + ".bib",
                                        masterBuffer()->temppath());
                        bool const success = in_file.copyTo(out_file);
                        if (!success) {
                                LYXERR0("Failed to copy '" << in_file
                                       << "' to '" << out_file << "'");
                        }
                } else if (!runparams.inComment && runparams.nice && not_from_texmf) {
                        runparams.exportdata->addExternalFile(tex_format, try_in_file, database + ".bib");
                        if (!isValidLaTeXFileName(database)) {
                                frontend::Alert::warning(_("Invalid filename"),
                                         _("The following filename will cause troubles "
                                               "when running the exported file through LaTeX: ") +
                                             from_utf8(database));
                        }
                        if (!isValidDVIFileName(database)) {
                                frontend::Alert::warning(_("Problematic filename for DVI"),
                                         _("The following filename can cause troubles "
                                               "when running the exported file through LaTeX "
                                                   "and opening the resulting DVI: ") +
                                             from_utf8(database), true);
                        }
                }

                if (add_extension)
                        database += ".bib";

                // FIXME UNICODE
                docstring const path = from_utf8(latex_path(database));

                if (contains(path, ' '))
                        found_space = true;
                string enc;
                if (params().useBiblatex() && !params().bibFileEncoding(utf8input).empty())
                        enc = params().bibFileEncoding(utf8input);

                bool recorded = false;
                for (auto const & pe : res) {
                        if (pe.first == path) {
                                recorded = true;
                                break;
                        }

                }
                if (!recorded)
                        res.push_back(make_pair(path, enc));
        }

        // Check if there are spaces in the path and warn BibTeX users, if so.
        // (biber can cope with such paths)
        if (!prefixIs(runparams.bibtex_command, "biber")) {
                // Post this warning only once.
                static bool warned_about_spaces = false;
                if (!warned_about_spaces &&
                    runparams.nice && found_space) {
                        warned_about_spaces = true;
                        Alert::warning(_("Export Warning!"),
                                       _("There are spaces in the paths to your BibTeX databases.\n"
                                                      "BibTeX will be unable to find them."));
                }
        }

        return res;
}



string Buffer::layoutPos() const
{
        return d->layout_position;
}


void Buffer::setLayoutPos(string const & path)
{
        if (path.empty()) {
                d->layout_position.clear();
                return;
        }

        LATTEST(FileName::isAbsolute(path));

        d->layout_position =
                to_utf8(makeRelPath(from_utf8(path), from_utf8(filePath())));

        if (d->layout_position.empty())
                d->layout_position = ".";
}


bool Buffer::hasReadonlyFlag() const
{
        return d->read_only;
}


bool Buffer::isReadonly() const
{
        return hasReadonlyFlag() || notifiesExternalModification();
}


void Buffer::setParent(Buffer const * buffer)
{
        // We need to do some work here to avoid recursive parent structures.
        // This is the easy case.
        if (buffer == this) {
                LYXERR0("Ignoring attempt to set self as parent in\n" << fileName());
                return;
        }
        // Now we check parents going upward, to make sure that IF we set the
        // parent as requested, we would not generate a recursive include.
        set<Buffer const *> sb;
        Buffer const * b = buffer;
        bool found_recursion = false;
        while (b) {
                if (sb.find(b) != sb.end()) {
                        found_recursion = true;
                        break;
                }
                sb.insert(b);
                b = b->parent();
        }

        if (found_recursion) {
                LYXERR0("Ignoring attempt to set parent of\n" <<
                        fileName() <<
                        "\nto " <<
                        buffer->fileName() <<
                        "\nbecause that would create a recursive inclusion.");
                return;
        }

        // We should be safe now.
        d->setParent(buffer);
        updateMacros();
}


Buffer const * Buffer::parent() const
{
        return d->parent();
}


ListOfBuffers Buffer::allRelatives() const
{
        ListOfBuffers lb = masterBuffer()->getDescendants();
        lb.push_front(const_cast<Buffer *>(masterBuffer()));
        return lb;
}


Buffer const * Buffer::masterBuffer() const
{
        Buffer const * const pbuf = d->parent();
        if (!pbuf)
                return this;

        return pbuf->masterBuffer();
}


bool Buffer::isChild(Buffer * child) const
{
        return d->children_positions.find(child) != d->children_positions.end();
}


DocIterator Buffer::firstChildPosition(Buffer const * child)
{
        Impl::BufferPositionMap::iterator it;
        it = d->children_positions.find(child);
        if (it == d->children_positions.end())
                return DocIterator(this);
        return it->second;
}


bool Buffer::hasChildren() const
{
        return !d->children_positions.empty();
}


void Buffer::collectChildren(ListOfBuffers & children, bool grand_children) const
{
        // loop over children
        for (auto const & p : d->children_positions) {
                Buffer * child = const_cast<Buffer *>(p.first);
                // No duplicates
                ListOfBuffers::const_iterator bit = find(children.begin(), children.end(), child);
                if (bit != children.end())
                        continue;
                children.push_back(child);
                if (grand_children)
                        // there might be grandchildren
                        child->collectChildren(children, true);
        }
}


ListOfBuffers Buffer::getChildren() const
{
        ListOfBuffers v;
        collectChildren(v, false);
        // Make sure we have not included ourselves.
        ListOfBuffers::iterator bit = find(v.begin(), v.end(), this);
        if (bit != v.end()) {
                LYXERR0("Recursive include detected in `" << fileName() << "'.");
                v.erase(bit);
        }
        return v;
}


ListOfBuffers Buffer::getDescendants() const
{
        ListOfBuffers v;
        collectChildren(v, true);
        // Make sure we have not included ourselves.
        ListOfBuffers::iterator bit = find(v.begin(), v.end(), this);
        if (bit != v.end()) {
                LYXERR0("Recursive include detected in `" << fileName() << "'.");
                v.erase(bit);
        }
        return v;
}


template<typename M>
typename M::const_iterator greatest_below(M & m, typename M::key_type const & x)
{
        if (m.empty())
                return m.end();

        typename M::const_iterator it = m.lower_bound(x);
        if (it == m.begin())
                return m.end();

        --it;
        return it;
}


MacroData const * Buffer::Impl::getBufferMacro(docstring const & name,
                                         DocIterator const & pos) const
{
        LYXERR(Debug::MACROS, "Searching for " << to_ascii(name) << " at " << pos);

        // if paragraphs have no macro context set, pos will be empty
        if (pos.empty())
                return nullptr;

        // we haven't found anything yet
        DocIterator bestPos = owner_->par_iterator_begin();
        MacroData const * bestData = nullptr;

        // find macro definitions for name
        NamePositionScopeMacroMap::const_iterator nameIt = macros.find(name);
        if (nameIt != macros.end()) {
                // find last definition in front of pos or at pos itself
                PositionScopeMacroMap::const_iterator it
                        = greatest_below(nameIt->second, pos);
                if (it != nameIt->second.end()) {
                        while (true) {
                                // scope ends behind pos?
                                if (pos < it->second.scope) {
                                        // Looks good, remember this. If there
                                        // is no external macro behind this,
                                        // we found the right one already.
                                        bestPos = it->first;
                                        bestData = &it->second.macro;
                                        break;
                                }

                                // try previous macro if there is one
                                if (it == nameIt->second.begin())
                                        break;
                                --it;
                        }
                }
        }

        // find macros in included files
        PositionScopeBufferMap::const_iterator it
                = greatest_below(position_to_children, pos);
        if (it == position_to_children.end())
                // no children before
                return bestData;

        while (true) {
                // do we know something better (i.e. later) already?
                if (it->first < bestPos )
                        break;

                // scope ends behind pos?
                if (pos < it->second.scope
                        && (cloned_buffer_ ||
                            theBufferList().isLoaded(it->second.buffer))) {
                        // look for macro in external file
                        macro_lock = true;
                        MacroData const * data
                                = it->second.buffer->getMacro(name, false);
                        macro_lock = false;
                        if (data) {
                                bestPos = it->first;
                                bestData = data;
                                break;
                        }
                }

                // try previous file if there is one
                if (it == position_to_children.begin())
                        break;
                --it;
        }

        // return the best macro we have found
        return bestData;
}


MacroData const * Buffer::getMacro(docstring const & name,
        DocIterator const & pos, bool global) const
{
        if (d->macro_lock)
                return nullptr;

        // query buffer macros
        MacroData const * data = d->getBufferMacro(name, pos);
        if (data != nullptr)
                return data;

        // If there is a master buffer, query that
        Buffer const * const pbuf = d->parent();
        if (pbuf) {
                d->macro_lock = true;
                MacroData const * macro = pbuf->getMacro(
                        name, *this, false);
                d->macro_lock = false;
                if (macro)
                        return macro;
        }

        if (global) {
                data = MacroTable::globalMacros().get(name);
                if (data != nullptr)
                        return data;
        }

        return nullptr;
}


MacroData const * Buffer::getMacro(docstring const & name, bool global) const
{
        // set scope end behind the last paragraph
        DocIterator scope = par_iterator_begin();
        scope.pit() = scope.lastpit() + 1;

        return getMacro(name, scope, global);
}


MacroData const * Buffer::getMacro(docstring const & name,
        Buffer const & child, bool global) const
{
        // look where the child buffer is included first
        Impl::BufferPositionMap::iterator it = d->children_positions.find(&child);
        if (it == d->children_positions.end())
                return nullptr;

        // check for macros at the inclusion position
        return getMacro(name, it->second, global);
}


void Buffer::Impl::updateMacros(DocIterator & it, DocIterator & scope)
{
        pit_type const lastpit = it.lastpit();

        // look for macros in each paragraph
        while (it.pit() <= lastpit) {
                Paragraph & par = it.paragraph();

                // iterate over the insets of the current paragraph
                for (auto const & insit : par.insetList()) {
                        it.pos() = insit.pos;

                        // is it a nested text inset?
                        if (insit.inset->asInsetText()) {
                                // Inset needs its own scope?
                                InsetText const * itext = insit.inset->asInsetText();
                                bool newScope = itext->isMacroScope();

                                // scope which ends just behind the inset
                                DocIterator insetScope = it;
                                ++insetScope.pos();

                                // collect macros in inset
                                it.push_back(CursorSlice(*insit.inset));
                                updateMacros(it, newScope ? insetScope : scope);
                                it.pop_back();
                                continue;
                        }

                        if (insit.inset->asInsetTabular()) {
                                CursorSlice slice(*insit.inset);
                                size_t const numcells = slice.nargs();
                                for (; slice.idx() < numcells; slice.forwardIdx()) {
                                        it.push_back(slice);
                                        updateMacros(it, scope);
                                        it.pop_back();
                                }
                                continue;
                        }

                        // is it an external file?
                        if (insit.inset->lyxCode() == INCLUDE_CODE) {
                                // get buffer of external file
                                InsetInclude const & incinset =
                                        static_cast<InsetInclude const &>(*insit.inset);
                                macro_lock = true;
                                Buffer * child = incinset.loadIfNeeded();
                                macro_lock = false;
                                if (!child)
                                        continue;

                                // register its position, but only when it is
                                // included first in the buffer
                                children_positions.insert({child, it});

                                // register child with its scope
                                position_to_children[it] = Impl::ScopeBuffer(scope, child);
                                continue;
                        }

                        InsetMath * im = insit.inset->asInsetMath();
                        if (doing_export && im)  {
                                InsetMathHull * hull = im->asHullInset();
                                if (hull)
                                        hull->recordLocation(it);
                        }

                        if (insit.inset->lyxCode() != MATHMACRO_CODE)
                                continue;

                        // get macro data
                        InsetMathMacroTemplate & macroTemplate =
                                *insit.inset->asInsetMath()->asMacroTemplate();
                        MacroContext mc(owner_, it);
                        macroTemplate.updateToContext(mc);

                        // valid?
                        bool valid = macroTemplate.validMacro();
                        // FIXME: Should be fixNameAndCheckIfValid() in fact,
                        // then the BufferView's cursor will be invalid in
                        // some cases which leads to crashes.
                        if (!valid)
                                continue;

                        // register macro
                        // FIXME (Abdel), I don't understand why we pass 'it' here
                        // instead of 'macroTemplate' defined above... is this correct?
                        macros[macroTemplate.name()][it] =
                                Impl::ScopeMacro(scope, MacroData(owner_, it));
                }

                // next paragraph
                it.pit()++;
                it.pos() = 0;
        }
}


void Buffer::updateMacros() const
{
        if (d->macro_lock)
                return;

        LYXERR(Debug::MACROS, "updateMacro of " << d->filename.onlyFileName());

        // start with empty table
        d->macros.clear();
        d->children_positions.clear();
        d->position_to_children.clear();

        // Iterate over buffer, starting with first paragraph
        // The scope must be bigger than any lookup DocIterator
        // later. For the global lookup, lastpit+1 is used, hence
        // we use lastpit+2 here.
        DocIterator it = par_iterator_begin();
        DocIterator outerScope = it;
        outerScope.pit() = outerScope.lastpit() + 2;
        d->updateMacros(it, outerScope);
}


void Buffer::getUsedBranches(std::list<docstring> & result, bool const from_master) const
{
        for (Inset const & it : inset()) {
                if (it.lyxCode() == BRANCH_CODE) {
                        InsetBranch const & br = static_cast<InsetBranch const &>(it);
                        docstring const name = br.branch();
                        if (!from_master && !params().branchlist().find(name))
                                result.push_back(name);
                        else if (from_master && !masterBuffer()->params().branchlist().find(name))
                                result.push_back(name);
                        continue;
                }
                if (it.lyxCode() == INCLUDE_CODE) {
                        // get buffer of external file
                        InsetInclude const & ins =
                                static_cast<InsetInclude const &>(it);
                        Buffer * child = ins.loadIfNeeded();
                        if (!child)
                                continue;
                        child->getUsedBranches(result, true);
                }
        }
        // remove duplicates
        result.unique();
}


void Buffer::updateMacroInstances(UpdateType utype) const
{
        LYXERR(Debug::MACROS, "updateMacroInstances for "
                << d->filename.onlyFileName());
        DocIterator it = doc_iterator_begin(this);
        it.forwardInset();
        DocIterator const end = doc_iterator_end(this);
        for (; it != end; it.forwardInset()) {
                // look for MathData cells in InsetMathNest insets
                InsetMath * minset = it.nextInset()->asInsetMath();
                if (!minset)
                        continue;

                // update macro in all cells of the InsetMathNest
                idx_type n = minset->nargs();
                MacroContext mc = MacroContext(this, it);
                for (idx_type i = 0; i < n; ++i) {
                        MathData & data = minset->cell(i);
                        data.updateMacros(nullptr, mc, utype, 0);
                }
        }
}


void Buffer::listMacroNames(MacroNameSet & macros) const
{
        if (d->macro_lock)
                return;

        d->macro_lock = true;

        // loop over macro names
        for (auto const & nameit : d->macros)
                macros.insert(nameit.first);

        // loop over children
        for (auto const & p : d->children_positions) {
                Buffer * child = const_cast<Buffer *>(p.first);
                // The buffer might have been closed (see #10766).
                if (theBufferList().isLoaded(child))
                        child->listMacroNames(macros);
        }

        // call parent
        Buffer const * const pbuf = d->parent();
        if (pbuf)
                pbuf->listMacroNames(macros);

        d->macro_lock = false;
}


void Buffer::listParentMacros(MacroSet & macros, LaTeXFeatures & features) const
{
        Buffer const * const pbuf = d->parent();
        if (!pbuf)
                return;

        MacroNameSet names;
        pbuf->listMacroNames(names);

        // resolve macros
        for (auto const & mit : names) {
                // defined?
                MacroData const * data = pbuf->getMacro(mit, *this, false);
                if (data) {
                        macros.insert(data);

                        // we cannot access the original InsetMathMacroTemplate anymore
                        // here to calls validate method. So we do its work here manually.
                        // FIXME: somehow make the template accessible here.
                        if (data->optionals() > 0)
                                features.require("xargs");
                }
        }
}


Buffer::References & Buffer::getReferenceCache(docstring const & label)
{
        if (d->parent())
                return const_cast<Buffer *>(masterBuffer())->getReferenceCache(label);

        RefCache::iterator it = d->ref_cache_.find(label);
        if (it != d->ref_cache_.end())
                return it->second;

        static References const dummy_refs = References();
        it = d->ref_cache_.insert(
                make_pair(label, dummy_refs)).first;
        return it->second;
}


Buffer::References const & Buffer::references(docstring const & label) const
{
        return const_cast<Buffer *>(this)->getReferenceCache(label);
}


void Buffer::addReference(docstring const & label, Inset * inset, ParIterator it)
{
        References & refs = getReferenceCache(label);
        refs.push_back(make_pair(inset, it));
}


void Buffer::setInsetLabel(docstring const & label, InsetLabel const * il,
                           bool const active)
{
        LabelInfo linfo;
        linfo.label = label;
        linfo.inset = il;
        linfo.active = active;
        masterBuffer()->d->label_cache_.push_back(linfo);
}


InsetLabel const * Buffer::insetLabel(docstring const & label,
                                      bool const active) const
{
        for (auto const & rc : masterBuffer()->d->label_cache_) {
                if (rc.label == label && (rc.active || !active))
                        return rc.inset;
        }
        return nullptr;
}


bool Buffer::activeLabel(docstring const & label) const
{
        return insetLabel(label, true) != nullptr;
}


void Buffer::clearReferenceCache() const
{
        if (!d->parent()) {
                d->ref_cache_.clear();
                d->label_cache_.clear();
        }
}


void Buffer::changeRefsIfUnique(docstring const & from, docstring const & to)
{
        //FIXME: This does not work for child documents yet.
        reloadBibInfoCache();

        // Check if the label 'from' appears more than once
        vector<docstring> labels;
        for (auto const & bibit : masterBibInfo())
                labels.push_back(bibit.first);

        if (count(labels.begin(), labels.end(), from) > 1)
                return;

        string const paramName = "key";
        UndoGroupHelper ugh(this);
        InsetIterator it = begin(inset());
        for (; it; ++it) {
                if (it->lyxCode() != CITE_CODE)
                        continue;
                InsetCommand * inset = it->asInsetCommand();
                docstring const oldValue = inset->getParam(paramName);
                if (oldValue == from) {
                        undo().recordUndo(CursorData(it));
                        inset->setParam(paramName, to);
                }
        }
}

// returns NULL if id-to-row conversion is unsupported
unique_ptr<TexRow> Buffer::getSourceCode(odocstream & os, string const & format,
                                         pit_type par_begin, pit_type par_end,
                                         OutputWhat output, bool master) const
{
        unique_ptr<TexRow> texrow;
        OutputParams runparams(&params().encoding());
        runparams.nice = true;
        runparams.flavor = params().getOutputFlavor(format);
        runparams.linelen = lyxrc.plaintext_linelen;
        // No side effect of file copying and image conversion
        runparams.dryrun = true;

        // Some macros rely on font encoding
        runparams.main_fontenc = params().main_font_encoding();

        // Use the right wrapping for the comment at the beginning of the generated
        // snippet, so that it is either valid LaTeX or valid XML (including HTML and DocBook).
        docstring comment_start = from_ascii("% ");
        docstring comment_end = from_ascii("");
        if (runparams.flavor == Flavor::Html || runparams.flavor == Flavor::DocBook5) {
                comment_start = from_ascii("<!-- ");
                comment_end = from_ascii(" -->");
        }

        if (output == CurrentParagraph) {
                runparams.par_begin = par_begin;
                runparams.par_end = par_end;
                if (par_begin + 1 == par_end) {
                        os << comment_start
                           << bformat(_("Preview source code for paragraph %1$d"), par_begin)
                           << comment_end
                           << "\n\n";
                } else {
                        os << comment_start
                           << bformat(_("Preview source code from paragraph %1$s to %2$s"),
                                        convert<docstring>(par_begin),
                                        convert<docstring>(par_end - 1))
                           << comment_end
                           << "\n\n";
                }
                // output paragraphs
                if (runparams.flavor == Flavor::LyX) {
                        Paragraph const & par = text().paragraphs()[par_begin];
                        ostringstream ods;
                        depth_type dt = par.getDepth();
                        par.write(ods, params(), dt);
                        os << from_utf8(ods.str());
                } else if (runparams.flavor == Flavor::Html) {
                        XMLStream xs(os);
                        setMathFlavor(runparams);
                        xhtmlParagraphs(text(), *this, xs, runparams);
                } else if (runparams.flavor == Flavor::Text) {
                        bool dummy = false;
                        // FIXME Handles only one paragraph, unlike the others.
                        // Probably should have some routine with a signature like them.
                        writePlaintextParagraph(*this,
                                text().paragraphs()[par_begin], os, runparams, dummy);
                } else if (runparams.flavor == Flavor::DocBook5) {
                        XMLStream xs{os};
                        docbookParagraphs(text(), *this, xs, runparams);
                } else {
                        // If we are previewing a paragraph, even if this is the
                        // child of some other buffer, let's cut the link here,
                        // so that no concurring settings from the master
                        // (e.g. branch state) interfere (see #8101).
                        if (!master)
                                d->ignore_parent = true;
                        // We need to validate the Buffer params' features here
                        // in order to know if we should output polyglossia
                        // macros (instead of babel macros)
                        LaTeXFeatures features(*this, params(), runparams);
                        validate(features);
                        runparams.use_polyglossia = features.usePolyglossia();
                        runparams.use_hyperref = features.isRequired("hyperref");
                        // latex or literate
                        otexstream ots(os);
                        // output above
                        ots.texrow().newlines(2);
                        // the real stuff
                        latexParagraphs(*this, text(), ots, runparams);
                        texrow = ots.releaseTexRow();

                        // Restore the parenthood
                        if (!master)
                                d->ignore_parent = false;
                }
        } else {
                os << comment_start;
                if (output == FullSource)
                        os << _("Preview source code");
                else if (output == OnlyPreamble)
                        os << _("Preview preamble");
                else if (output == OnlyBody)
                        os << _("Preview body");
                os << comment_end;
                os << "\n\n";
                if (runparams.flavor == Flavor::LyX) {
                        ostringstream ods;
                        if (output == FullSource)
                                write(ods);
                        else if (output == OnlyPreamble)
                                params().writeFile(ods, this);
                        else if (output == OnlyBody)
                                text().write(ods);
                        os << from_utf8(ods.str());
                } else if (runparams.flavor == Flavor::Html) {
                        writeLyXHTMLSource(os, runparams, output);
                } else if (runparams.flavor == Flavor::Text) {
                        if (output == OnlyPreamble)
                                os << "% "<< _("Plain text does not have a preamble.");
                        else
                                writePlaintextFile(*this, os, runparams);
                } else if (runparams.flavor == Flavor::DocBook5) {
                        writeDocBookSource(os, runparams, output);
                } else {
                        // latex or literate
                        otexstream ots(os);
                        // output above
                        ots.texrow().newlines(2);
                        if (master)
                                runparams.is_child = true;
                        updateBuffer();
                        writeLaTeXSource(ots, string(), runparams, output);
                        texrow = ots.releaseTexRow();
                }
        }
        return texrow;
}


ErrorList & Buffer::errorList(string const & type) const
{
        return d->errorLists[type];
}


void Buffer::updateTocItem(std::string const & type,
        DocIterator const & dit) const
{
        if (d->gui_)
                d->gui_->updateTocItem(type, dit);
}


void Buffer::structureChanged() const
{
        if (d->gui_)
                d->gui_->structureChanged();
}


void Buffer::errors(string const & err, bool from_master) const
{
        if (d->gui_)
                d->gui_->errors(err, from_master);
}


void Buffer::message(docstring const & msg) const
{
        if (d->gui_)
                d->gui_->message(msg);
}


void Buffer::setBusy(bool on) const
{
        if (d->gui_)
                d->gui_->setBusy(on);
}


void Buffer::updateTitles() const
{
        if (d->wa_)
                d->wa_->updateTitles();
}


void Buffer::scheduleRedrawWorkAreas() const
{
        if (d->wa_)
                d->wa_->scheduleRedraw();
}


void Buffer::resetAutosaveTimers() const
{
        if (d->gui_)
                d->gui_->resetAutosaveTimers();
}


bool Buffer::hasGuiDelegate() const
{
        return d->gui_;
}


void Buffer::setGuiDelegate(frontend::GuiBufferDelegate * gui)
{
        d->gui_ = gui;
}


FileName Buffer::getEmergencyFileName() const
{
        return FileName(d->filename.absFileName() + ".emergency");
}


FileName Buffer::getAutosaveFileName() const
{
        // if the document is unnamed try to save in the backup dir, else
        // in the default document path, and as a last try in the filePath,
        // which will most often be the temporary directory
        string fpath;
        if (isUnnamed())
                fpath = lyxrc.backupdir_path.empty() ? lyxrc.document_path
                        : lyxrc.backupdir_path;
        if (!isUnnamed() || fpath.empty() || !FileName(fpath).exists())
                fpath = filePath();

        string const fname = "#" + d->filename.onlyFileName() + "#";

        return makeAbsPath(fname, fpath);
}


void Buffer::removeAutosaveFile() const
{
        FileName const f = getAutosaveFileName();
        if (f.exists())
                f.removeFile();
}


void Buffer::moveAutosaveFile(FileName const & oldauto) const
{
        FileName const newauto = getAutosaveFileName();
        oldauto.refresh();
        if (newauto != oldauto && oldauto.exists())
                if (!oldauto.moveTo(newauto))
                        LYXERR0("Unable to move autosave file `" << oldauto << "'!");
}


bool Buffer::autoSave() const
{
        Buffer const * buf = d->cloned_buffer_ ? d->cloned_buffer_ : this;
        if (buf->d->bak_clean || hasReadonlyFlag())
                return true;

        message(_("Autosaving current document..."));
        buf->d->bak_clean = true;

        FileName const fname = getAutosaveFileName();
        LASSERT(d->cloned_buffer_, return false);

        // If this buffer is cloned, we assume that
        // we are running in a separate thread already.
        TempFile tempfile("lyxautoXXXXXX.lyx");
        tempfile.setAutoRemove(false);
        FileName const tmp_ret = tempfile.name();
        if (!tmp_ret.empty()) {
                writeFile(tmp_ret);
                // assume successful write of tmp_ret
                if (tmp_ret.moveTo(fname))
                        return true;
        }
        // failed to write/rename tmp_ret so try writing direct
        return writeFile(fname);
}


void Buffer::setExportStatus(bool e) const
{
        d->doing_export = e;
        ListOfBuffers clist = getDescendants();
        for (auto const & bit : clist)
                bit->d->doing_export = e;
}


bool Buffer::isExporting() const
{
        return d->doing_export;
}


Buffer::ExportStatus Buffer::doExport(string const & target, bool put_in_tempdir)
        const
{
        string result_file;
        return doExport(target, put_in_tempdir, result_file);
}

Buffer::ExportStatus Buffer::doExport(string const & target, bool put_in_tempdir,
        string & result_file) const
{
        bool const update_unincluded =
                        params().maintain_unincluded_children != BufferParams::CM_None
                        && !params().getIncludedChildren().empty();

        // (1) export with all included children (omit \includeonly)
        if (update_unincluded) {
                ExportStatus const status =
                        doExport(target, put_in_tempdir, true, result_file);
                if (status != ExportSuccess)
                        return status;
        }
        // (2) export with included children only
        return doExport(target, put_in_tempdir, false, result_file);
}


void Buffer::setMathFlavor(OutputParams & op) const
{
        // Passes the way to generate formulae to the XHTML output code.
        // In particular, this function has no impact on the DocBook code, as it
        // uses another mechanism to handle math flavours.
        switch (params().html_math_output) {
        case BufferParams::MathML:
                op.math_flavor = OutputParams::MathAsMathML;
                break;
        case BufferParams::HTML:
                op.math_flavor = OutputParams::MathAsHTML;
                break;
        case BufferParams::Images:
                op.math_flavor = OutputParams::MathAsImages;
                break;
        case BufferParams::LaTeX:
                op.math_flavor = OutputParams::MathAsLaTeX;
                break;
        }
}


Buffer::ExportStatus Buffer::doExport(string const & target, bool put_in_tempdir,
        bool includeall, string & result_file) const
{
        LYXERR(Debug::FILES, "target=" << target);
        OutputParams runparams(&params().encoding());
        string format = target;
        string dest_filename;
        size_t pos = target.find(' ');
        if (pos != string::npos) {
                dest_filename = target.substr(pos + 1, target.length() - pos - 1);
                format = target.substr(0, pos);
                if (format == "default")
                        format = params().getDefaultOutputFormat();
                runparams.export_folder = FileName(dest_filename).onlyPath().realPath();
                FileName(dest_filename).onlyPath().createPath();
                LYXERR(Debug::FILES, "format=" << format << ", dest_filename=" << dest_filename << ", export_folder=" << runparams.export_folder);
        }
        MarkAsExporting exporting(this);
        string backend_format;
        runparams.flavor = Flavor::LaTeX;
        runparams.linelen = lyxrc.plaintext_linelen;
        runparams.includeall = includeall;
        vector<string> backs = params().backends();
        Converters converters = theConverters();
        bool need_nice_file = false;
        if (find(backs.begin(), backs.end(), format) == backs.end()) {
                // Get the shortest path to format
                converters.buildGraph();
                Graph::EdgePath path;
                for (string const & sit : backs) {
                        Graph::EdgePath p = converters.getPath(sit, format);
                        if (!p.empty() && (path.empty() || p.size() < path.size())) {
                                backend_format = sit;
                                path = p;
                        }
                }
                if (path.empty()) {
                        if (!put_in_tempdir) {
                                // Only show this alert if this is an export to a non-temporary
                                // file (not for previewing).
                                docstring s = bformat(_("No information for exporting the format %1$s."),
                                                      translateIfPossible(theFormats().prettyName(format)));
                                if (format == "pdf4")
                                        s += "\n"
                                          + bformat(_("Hint: use non-TeX fonts or set input encoding "
                                                  " to '%1$s'"), from_utf8(encodings.fromLyXName("ascii")->guiName()));
                                Alert::error(_("Couldn't export file"), s);
                        }
                        return ExportNoPathToFormat;
                }
                runparams.flavor = converters.getFlavor(path, this);
                runparams.hyperref_driver = converters.getHyperrefDriver(path);
                for (auto const & edge : path)
                        if (theConverters().get(edge).nice()) {
                                need_nice_file = true;
                                break;
                        }

        } else {
                backend_format = format;
                LYXERR(Debug::FILES, "backend_format=" << backend_format);
                // FIXME: Don't hardcode format names here, but use a flag
                if (backend_format == "pdflatex")
                        runparams.flavor = Flavor::PdfLaTeX;
                else if (backend_format == "luatex")
                        runparams.flavor = Flavor::LuaTeX;
                else if (backend_format == "dviluatex")
                        runparams.flavor = Flavor::DviLuaTeX;
                else if (backend_format == "xetex")
                        runparams.flavor = Flavor::XeTeX;
        }

        string filename = latexName(false);
        filename = addName(temppath(), filename);
        filename = changeExtension(filename,
                                   theFormats().extension(backend_format));
        LYXERR(Debug::FILES, "filename=" << filename);

        // Plain text backend
        if (backend_format == "text") {
                runparams.flavor = Flavor::Text;
                try {
                        writePlaintextFile(*this, FileName(filename), runparams);
                }
                catch (ConversionException const &) { return ExportCancel; }
        }
        // HTML backend
        else if (backend_format == "xhtml") {
                runparams.flavor = Flavor::Html;
                setMathFlavor(runparams);
                if (makeLyXHTMLFile(FileName(filename), runparams) == ExportKilled)
                        return ExportKilled;
        } else if (backend_format == "lyx")
                writeFile(FileName(filename));
        // DocBook backend
        else if (backend_format == "docbook5") {
                runparams.flavor = Flavor::DocBook5;
                runparams.nice = false;
                if (makeDocBookFile(FileName(filename), runparams) == ExportKilled)
                        return ExportKilled;
        }
        // LaTeX backend
        else if (backend_format == format || need_nice_file) {
                runparams.nice = true;
                ExportStatus const retval =
                        makeLaTeXFile(FileName(filename), string(), runparams);
                if (retval == ExportKilled)
                        return ExportKilled;
                if (d->cloned_buffer_)
                        d->cloned_buffer_->d->errorLists["Export"] = d->errorLists["Export"];
                if (retval != ExportSuccess)
                        return retval;
        } else if (!lyxrc.tex_allows_spaces
                   && contains(filePath(), ' ')) {
                Alert::error(_("File name error"),
                        bformat(_("The directory path to the document\n%1$s\n"
                            "contains spaces, but your TeX installation does "
                            "not allow them. You should save the file to a directory "
                                        "whose name does not contain spaces."), from_utf8(filePath())));
                return ExportTexPathHasSpaces;
        } else {
                runparams.nice = false;
                ExportStatus const retval =
                        makeLaTeXFile(FileName(filename), filePath(), runparams);
                if (retval == ExportKilled)
                        return ExportKilled;
                if (d->cloned_buffer_)
                        d->cloned_buffer_->d->errorLists["Export"] = d->errorLists["Export"];
                if (retval != ExportSuccess)
                        return ExportError;
        }

        string const error_type = (format == "program")
                ? "Build" : params().bufferFormat();
        ErrorList & error_list = d->errorLists[error_type];
        string const ext = theFormats().extension(format);
        FileName const tmp_result_file(changeExtension(filename, ext));
        Converters::RetVal const retval = 
                converters.convert(this, FileName(filename), tmp_result_file,
                                   FileName(absFileName()), backend_format, format,
                                   error_list, Converters::none, includeall);
        if (retval == Converters::KILLED)
                return ExportCancel;
        bool success = (retval == Converters::SUCCESS);

        // Emit the signal to show the error list or copy it back to the
        // cloned Buffer so that it can be emitted afterwards.
        if (format != backend_format) {
                if (runparams.silent)
                        error_list.clear();
                else if (d->cloned_buffer_)
                        d->cloned_buffer_->d->errorLists[error_type] =
                                d->errorLists[error_type];
                else
                        errors(error_type);
                // also to the children, in case of master-buffer-view
                ListOfBuffers clist = getDescendants();
                for (auto const & bit : clist) {
                        if (runparams.silent)
                                bit->d->errorLists[error_type].clear();
                        else if (d->cloned_buffer_) {
                                // Enable reverse search by copying back the
                                // texrow object to the cloned buffer.
                                // FIXME: this is not thread safe.
                                bit->d->cloned_buffer_->d->texrow = bit->d->texrow;
                                bit->d->cloned_buffer_->d->errorLists[error_type] =
                                        bit->d->errorLists[error_type];
                        } else
                                bit->errors(error_type, true);
                }
        }

        if (d->cloned_buffer_) {
                // Enable reverse dvi or pdf to work by copying back the texrow
                // object to the cloned buffer.
                // FIXME: There is a possibility of concurrent access to texrow
                // here from the main GUI thread that should be securized.
                d->cloned_buffer_->d->texrow = d->texrow;
                string const err_type = params().bufferFormat();
                d->cloned_buffer_->d->errorLists[error_type] = d->errorLists[err_type];
        }


        if (put_in_tempdir) {
                result_file = tmp_result_file.absFileName();
                return success ? ExportSuccess : ExportConverterError;
        }

        if (dest_filename.empty())
                result_file = changeExtension(d->exportFileName().absFileName(), ext);
        else
                result_file = dest_filename;
        // We need to copy referenced files (e.g. included graphics
        // if format == "dvi") to the result dir.
        vector<ExportedFile> const extfiles =
                runparams.exportdata->externalFiles(format);
        string const dest = runparams.export_folder.empty() ?
                onlyPath(result_file) : runparams.export_folder;
        bool use_force = use_gui ? lyxrc.export_overwrite == ALL_FILES
                                 : force_overwrite == ALL_FILES;
        CopyStatus status = use_force ? FORCE : SUCCESS;

        for (ExportedFile const & exp : extfiles) {
                if (status == CANCEL) {
                        message(_("Document export cancelled."));
                        return ExportCancel;
                }
                string const fmt = theFormats().getFormatFromFile(exp.sourceName);
                string fixedName = exp.exportName;
                if (!runparams.export_folder.empty()) {
                        // Relative pathnames starting with ../ will be sanitized
                        // if exporting to a different folder
                        while (fixedName.substr(0, 3) == "../")
                                fixedName = fixedName.substr(3, fixedName.length() - 3);
                }
                FileName fixedFileName = makeAbsPath(fixedName, dest);
                fixedFileName.onlyPath().createPath();
                status = copyFile(fmt, exp.sourceName,
                        fixedFileName,
                        exp.exportName, status == FORCE,
                        runparams.export_folder.empty());
        }


        if (tmp_result_file.exists()) {
                // Finally copy the main file
                use_force = use_gui ? lyxrc.export_overwrite != NO_FILES
                                    : force_overwrite != NO_FILES;
                if (status == SUCCESS && use_force)
                        status = FORCE;
                status = copyFile(format, tmp_result_file,
                        FileName(result_file), result_file,
                        status == FORCE);
                if (status == CANCEL) {
                        message(_("Document export cancelled."));
                        return ExportCancel;
                } else {
                        message(bformat(_("Document exported as %1$s "
                                "to file `%2$s'"),
                                translateIfPossible(theFormats().prettyName(format)),
                                makeDisplayPath(result_file)));
                }
        } else {
                // This must be a dummy converter like fax (bug 1888)
                message(bformat(_("Document exported as %1$s"),
                        translateIfPossible(theFormats().prettyName(format))));
        }

        return success ? ExportSuccess : ExportConverterError;
}


Buffer::ExportStatus Buffer::preview(string const & format) const
{
        bool const update_unincluded =
                        params().maintain_unincluded_children != BufferParams::CM_None
                        && !params().getIncludedChildren().empty();
        return preview(format, update_unincluded);
}


Buffer::ExportStatus Buffer::preview(string const & format, bool includeall) const
{
        MarkAsExporting exporting(this);
        string result_file;
        // (1) export with all included children (omit \includeonly)
        if (includeall) {
                ExportStatus const status = doExport(format, true, true, result_file);
                if (status != ExportSuccess)
                        return status;
        }
        // (2) export with included children only
        ExportStatus const status = doExport(format, true, false, result_file);
        FileName const previewFile(result_file);

        Impl * theimpl = isClone() ? d->cloned_buffer_->d : d;
        theimpl->preview_file_ = previewFile;
        theimpl->preview_format_ = format;
        theimpl->require_fresh_start_ = (status != ExportSuccess);

        if (status != ExportSuccess)
                return status;

        if (previewFile.exists())
                return theFormats().view(*this, previewFile, format) ?
                        PreviewSuccess : PreviewError;

        // Successful export but no output file?
        // Probably a bug in error detection.
        LATTEST(status != ExportSuccess);
        return status;
}


Buffer::ReadStatus Buffer::extractFromVC()
{
        bool const found = LyXVC::file_not_found_hook(d->filename);
        if (!found)
                return ReadFileNotFound;
        if (!d->filename.isReadableFile())
                return ReadVCError;
        return ReadSuccess;
}


Buffer::ReadStatus Buffer::loadEmergency()
{
        FileName const emergencyFile = getEmergencyFileName();
        if (!emergencyFile.exists()
                  || emergencyFile.lastModified() <= d->filename.lastModified())
                return ReadFileNotFound;

        docstring const file = makeDisplayPath(d->filename.absFileName(), 20);
        docstring const text = bformat(_("An emergency save of the document "
                "%1$s exists.\n\nRecover emergency save?"), file);

        int const load_emerg = Alert::prompt(_("Load emergency save?"), text,
                0, 3, _("&Recover"), _("&Load Original"), _("&Only show difference"), _("&Cancel"));

        switch (load_emerg)
        {
        case 0: {
                docstring str;
                ReadStatus const ret_llf = loadThisLyXFile(emergencyFile);
                bool const success = (ret_llf == ReadSuccess);
                if (success) {
                        if (hasReadonlyFlag()) {
                                Alert::warning(_("File is read-only"),
                                        bformat(_("An emergency file is successfully loaded, "
                                        "but the original file %1$s is marked read-only. "
                                        "Please make sure to save the document as a different "
                                        "file."), from_utf8(d->filename.absFileName())));
                        }
                        markDirty();
                        lyxvc().file_found_hook(d->filename);
                        str = _("Document was successfully recovered.");
                } else
                        str = _("Document was NOT successfully recovered.");
                str += "\n\n" + bformat(_("Remove emergency file now?\n(%1$s)"),
                        makeDisplayPath(emergencyFile.absFileName()));

                int const del_emerg =
                        Alert::prompt(_("Delete emergency file?"), str, 1, 1,
                                _("&Remove"), _("&Keep"));
                if (del_emerg == 0) {
                        emergencyFile.removeFile();
                        if (success)
                                Alert::warning(_("Emergency file deleted"),
                                        _("Do not forget to save your file now!"), true);
                        }
                return success ? ReadSuccess : ReadEmergencyFailure;
        }
        case 1: {
                int const del_emerg =
                        Alert::prompt(_("Delete emergency file?"),
                                _("Remove emergency file now?"), 1, 1,
                                _("&Remove"), _("&Keep"));
                if (del_emerg == 0)
                        emergencyFile.removeFile();
                else {
                        // See bug #11464
                        FileName newname;
                        string const ename = emergencyFile.absFileName();
                        bool noname = true;
                        // Surely we can find one in 100 tries?
                        for (int i = 1; i < 100; ++i) {
                                newname.set(ename + to_string(i) + ".lyx");
                                if (!newname.exists()) {
                                        noname = false;
                                        break;
                                }
                        }
                        if (!noname) {
                                // renameTo returns true on success. So inverting that
                                // will give us true if we fail.
                                noname = !emergencyFile.renameTo(newname);
                        }
                        if (noname) {
                                Alert::warning(_("Can't rename emergency file!"),
                                        _("LyX was unable to rename the emergency file. "
                                          "You should do so manually. Otherwise, you will be "
                                          "asked about it again the next time you try to load "
                                          "this file, and may over-write your own work."));
                        } else {
                                Alert::warning(_("Emergency File Renames"),
                                        bformat(_("Emergency file renamed as:\n %1$s"),
                                        from_utf8(newname.onlyFileName())));
                        }
                }
                return ReadOriginal;
        }

        case 2: {
                string const f1 = d->filename.absFileName();
                string const f2 = emergencyFile.absFileName();
                if (loadThisLyXFile(d->filename) != ReadSuccess)
                        return ReadCancel;
                string const par = "compare run-blocking " + quoteName(f1) + " " + quoteName(f2);
                LYXERR(Debug::FILES, par << "\n");
                lyx::dispatch(FuncRequest(LFUN_DIALOG_SHOW, par));

                //release the emergency buffer loaded by compare
                Buffer * emerBuffer = theBufferList().getBuffer(emergencyFile);
                if (emerBuffer)
                        theBufferList().release(emerBuffer);

                return ReadCancel; //Release the buffer of Original immediatelly
        }
        default:
                break;
        }
        return ReadCancel;
}


Buffer::ReadStatus Buffer::loadAutosave()
{
        // Now check if autosave file is newer.
        FileName const autosaveFile = getAutosaveFileName();
        if (!autosaveFile.exists()
                  || autosaveFile.lastModified() <= d->filename.lastModified())
                return ReadFileNotFound;

        docstring const file = makeDisplayPath(d->filename.absFileName(), 20);
        docstring const text = bformat(_("The backup of the document %1$s "
                "is newer.\n\nLoad the backup instead?"), file);
        int const ret = Alert::prompt(_("Load backup?"), text, 0, 2,
                _("&Load backup"), _("Load &original"), _("&Cancel"));

        switch (ret)
        {
        case 0: {
                ReadStatus const ret_llf = loadThisLyXFile(autosaveFile);
                // the file is not saved if we load the autosave file.
                if (ret_llf == ReadSuccess) {
                        if (hasReadonlyFlag()) {
                                Alert::warning(_("File is read-only"),
                                        bformat(_("A backup file is successfully loaded, "
                                        "but the original file %1$s is marked read-only. "
                                        "Please make sure to save the document as a "
                                        "different file."),
                                        from_utf8(d->filename.absFileName())));
                        }
                        markDirty();
                        lyxvc().file_found_hook(d->filename);
                        return ReadSuccess;
                }
                return ReadAutosaveFailure;
        }
        case 1:
                // Here we delete the autosave
                autosaveFile.removeFile();
                return ReadOriginal;
        default:
                break;
        }
        return ReadCancel;
}


Buffer::ReadStatus Buffer::loadLyXFile()
{
        if (!d->filename.isReadableFile()) {
                ReadStatus const ret_rvc = extractFromVC();
                if (ret_rvc != ReadSuccess)
                        return ret_rvc;
        }

        ReadStatus const ret_re = loadEmergency();
        if (ret_re == ReadSuccess || ret_re == ReadCancel)
                return ret_re;

        ReadStatus const ret_ra = loadAutosave();
        if (ret_ra == ReadSuccess || ret_ra == ReadCancel)
                return ret_ra;

        return loadThisLyXFile(d->filename);
}


Buffer::ReadStatus Buffer::loadThisLyXFile(FileName const & fn)
{
        return readFile(fn);
}


void Buffer::Impl::traverseErrors(TeXErrors::Errors::const_iterator err, TeXErrors::Errors::const_iterator end, ErrorList & errorList) const
{
        for (; err != end; ++err) {
                TexRow::TextEntry start = TexRow::text_none, end = TexRow::text_none;
                int errorRow = err->error_in_line;
                Buffer const * buf = nullptr;
                Impl const * p = this;
                if (err->child_name.empty())
                        tie(start, end) = p->texrow.getEntriesFromRow(errorRow);
                else {
                        // The error occurred in a child
                        for (Buffer const * child : owner_->getDescendants()) {
                                string const child_name =
                                        DocFileName(changeExtension(child->absFileName(), "tex")).
                                        mangledFileName();
                                if (err->child_name != child_name)
                                        continue;
                                tie(start, end) = child->d->texrow.getEntriesFromRow(errorRow);
                                if (!TexRow::isNone(start)) {
                                        buf = this->cloned_buffer_
                                                ? child->d->cloned_buffer_->d->owner_
                                                : child->d->owner_;
                                        p = child->d;
                                        break;
                                }
                        }
                }
                errorList.push_back(ErrorItem(err->error_desc, err->error_text,
                                              start, end, buf));
        }
}


void Buffer::bufferErrors(TeXErrors const & terr, ErrorList & errorList) const
{
        TeXErrors::Errors::const_iterator err = terr.begin();
        TeXErrors::Errors::const_iterator end = terr.end();

        d->traverseErrors(err, end, errorList);
}


void Buffer::bufferRefs(TeXErrors const & terr, ErrorList & errorList) const
{
        TeXErrors::Errors::const_iterator err = terr.begin_ref();
        TeXErrors::Errors::const_iterator end = terr.end_ref();

        d->traverseErrors(err, end, errorList);
}


void Buffer::updateBuffer() const
{
        updateBuffer(UpdateMaster, InternalUpdate);
        d->need_update = false;
}


void Buffer::updateBuffer(UpdateScope scope, UpdateType utype) const
{
        LBUFERR(!text().paragraphs().empty());

        // This can be called when loading a file, so that there be no
        // open undo group.
        UndoGroupHelper ugh(const_cast<Buffer *>(this));

        // Use the master text class also for child documents
        Buffer const * const master = masterBuffer();
        DocumentClass const & textclass = master->params().documentClass();

        docstring_list old_bibfiles;
        // Do this only if we are the top-level Buffer. We also need to account
        // for the case of a previewed child with ignored parent here.
        if (master == this && !d->ignore_parent) {
                textclass.counters().reset(from_ascii("bibitem"));
                reloadBibInfoCache();
                // we will re-read this cache as we go through, but we need
                // to know whether it's changed to know whether we need to
                // update the bibinfo cache.
                old_bibfiles = d->bibfiles_cache_;
                d->bibfiles_cache_.clear();
        }

        // keep the buffers to be children in this set. If the call from the
        // master comes back we can see which of them were actually seen (i.e.
        // via an InsetInclude). The remaining ones in the set need still be updated.
        static std::set<Buffer const *> bufToUpdate;
        if (scope == UpdateMaster) {
                // If this is a child document start with the master
                if (master != this) {
                        bufToUpdate.insert(this);
                        master->updateBuffer(UpdateMaster, utype);
                        // If the master buffer has no gui associated with it, then the TocModel is
                        // not updated during the updateBuffer call and TocModel::toc_ is invalid
                        // (bug 5699). The same happens if the master buffer is open in a different
                        // window. This test catches both possibilities.
                        // See: https://marc.info/?l=lyx-devel&m=138590578911716&w=2
                        // There remains a problem here: If there is another child open in yet a third
                        // window, that TOC is not updated. So some more general solution is needed at
                        // some point.
                        if (master->d->gui_ != d->gui_)
                                structureChanged();

                        // was buf referenced from the master (i.e. not in bufToUpdate anymore)?
                        if (bufToUpdate.find(this) == bufToUpdate.end())
                                return;
                }

                // start over the counters in the master
                textclass.counters().reset();
        }

        // update will be done below for this buffer
        bufToUpdate.erase(this);

        // update all caches
        clearReferenceCache();
        updateMacros();

        Buffer & cbuf = const_cast<Buffer &>(*this);
        // if we are reloading, then we could have a dangling TOC,
        // in effect. so we need to go ahead and reset, even though
        // we will do so again when we rebuild the TOC later.
        cbuf.tocBackend().reset();

        // do the real work
        ParIterator parit = cbuf.par_iterator_begin();
        if (scope == UpdateMaster)
                clearIncludeList();
        updateBuffer(parit, utype);

        // If this document has siblings, then update the TocBackend later. The
        // reason is to ensure that later siblings are up to date when e.g. the
        // broken or not status of references is computed. The update is called
        // in InsetInclude::addToToc.
        if (master != this)
                return;

        // if the bibfiles changed, the cache of bibinfo is invalid
        docstring_list new_bibfiles = d->bibfiles_cache_;
        // this is a trick to determine whether the two vectors have
        // the same elements.
        sort(new_bibfiles.begin(), new_bibfiles.end());
        sort(old_bibfiles.begin(), old_bibfiles.end());
        if (old_bibfiles != new_bibfiles) {
                LYXERR(Debug::FILES, "Reloading bibinfo cache.");
                invalidateBibinfoCache();
                reloadBibInfoCache();
                // We relied upon the bibinfo cache when recalculating labels. But that
                // cache was invalid, although we didn't find that out until now. So we
                // have to do it all again.
                // That said, the only thing we really need to do is update the citation
                // labels. Nothing else will have changed. So we could create a new 
                // UpdateType that would signal that fact, if we needed to do so.
                parit = cbuf.par_iterator_begin();
                // we will be re-doing the counters and references and such.
                textclass.counters().reset();
                clearReferenceCache();
                // we should not need to do this again?
                // updateMacros();
                updateBuffer(parit, utype);
                // this will already have been done by reloadBibInfoCache();
                // d->bibinfo_cache_valid_ = true;
        }
        else {
                LYXERR(Debug::FILES, "Bibfiles unchanged.");
                // this is also set to true on the other path, by reloadBibInfoCache.
                d->bibinfo_cache_valid_ = true;
        }
        d->cite_labels_valid_ = true;
        /// FIXME: Perf
        clearIncludeList();
        cbuf.tocBackend().update(true, utype);
        if (scope == UpdateMaster)
                cbuf.structureChanged();

        d->need_update = false;
}


static depth_type getDepth(DocIterator const & it)
{
        depth_type depth = 0;
        for (size_t i = 0 ; i < it.depth() ; ++i)
                if (!it[i].inset().inMathed())
                        depth += it[i].paragraph().getDepth() + 1;
        // remove 1 since the outer inset does not count
        // we should have at least one non-math inset, so
        // depth should nevery be 0. but maybe it is worth
        // marking this, just in case.
        LATTEST(depth > 0);
        // coverity[INTEGER_OVERFLOW]
        return depth - 1;
}

static depth_type getItemDepth(ParIterator const & it)
{
        Paragraph const & par = *it;
        LabelType const labeltype = par.layout().labeltype;

        if (labeltype != LABEL_ENUMERATE && labeltype != LABEL_ITEMIZE)
                return 0;

        // this will hold the lowest depth encountered up to now.
        depth_type min_depth = getDepth(it);
        ParIterator prev_it = it;
        while (true) {
                if (prev_it.pit())
                        --prev_it.top().pit();
                else {
                        // start of nested inset: go to outer par
                        prev_it.pop_back();
                        if (prev_it.empty()) {
                                // start of document: nothing to do
                                return 0;
                        }
                }

                // We search for the first paragraph with same label
                // that is not more deeply nested.
                Paragraph & prev_par = *prev_it;
                depth_type const prev_depth = getDepth(prev_it);
                if (labeltype == prev_par.layout().labeltype) {
                        if (prev_depth < min_depth)
                                return prev_par.itemdepth + 1;
                        if (prev_depth == min_depth)
                                return prev_par.itemdepth;
                }
                min_depth = min(min_depth, prev_depth);
                // small optimization: if we are at depth 0, we won't
                // find anything else
                if (prev_depth == 0)
                        return 0;
        }
}


static bool needEnumCounterReset(ParIterator const & it)
{
        Paragraph const & par = *it;
        LASSERT(par.layout().labeltype == LABEL_ENUMERATE, return false);
        depth_type const cur_depth = par.getDepth();
        ParIterator prev_it = it;
        while (prev_it.pit()) {
                --prev_it.top().pit();
                Paragraph const & prev_par = *prev_it;
                if (prev_par.getDepth() <= cur_depth)
                        return prev_par.layout().name() != par.layout().name();
        }
        // start of nested inset: reset
        return true;
}


// set the label of a paragraph. This includes the counters.
void Buffer::Impl::setLabel(ParIterator & it, UpdateType utype) const
{
        BufferParams const & bp = owner_->masterBuffer()->params();
        DocumentClass const & textclass = bp.documentClass();
        Paragraph & par = it.paragraph();
        Layout const & layout = par.layout();
        Counters & counters = textclass.counters();

        if (par.params().startOfAppendix()) {
                // We want to reset the counter corresponding to toplevel sectioning
                Layout const & lay = textclass.getTOCLayout();
                docstring const cnt = lay.counter;
                if (!cnt.empty())
                        counters.reset(cnt);
                counters.appendix(true);
        }
        par.params().appendix(counters.appendix());

        // Compute the item depth of the paragraph
        par.itemdepth = getItemDepth(it);

        if (layout.margintype == MARGIN_MANUAL) {
                if (par.params().labelWidthString().empty())
                        par.params().labelWidthString(par.expandLabel(layout, bp));
        } else if (layout.latextype == LATEX_BIB_ENVIRONMENT) {
                // we do not need to do anything here, since the empty case is
                // handled during export.
        } else {
                par.params().labelWidthString(docstring());
        }

        switch(layout.labeltype) {
        case LABEL_ITEMIZE: {
                par.params().labelString(
                        (par.itemdepth < 4)
                                        ? bp.user_defined_bullet(par.itemdepth).getLabel()
                                          // Display fallback for too deeply nested items
                                        : bformat(from_ascii("[?%1$d]"), int(par.itemdepth + 1)));
                break;
        }

        case LABEL_ENUMERATE: {
                docstring enumcounter = layout.counter.empty() ? from_ascii("enum") : layout.counter;

                switch (par.itemdepth) {
                case 2:
                        enumcounter += 'i';
                        // fall through
                case 1:
                        enumcounter += 'i';
                        // fall through
                case 0:
                        enumcounter += 'i';
                        break;
                case 3:
                        enumcounter += "iv";
                        break;
                default:
                        // not a valid enumdepth...
                        break;
                }

                if (needEnumCounterReset(it)) {
                        // Increase the parent counter?
                        if (layout.stepparentcounter)
                                counters.stepParent(enumcounter, utype);
                        // Maybe we have to reset the enumeration counter.
                        if (!layout.resumecounter)
                                counters.reset(enumcounter);
                }
                counters.step(enumcounter, utype);

                string const & lang = par.getParLanguage(bp)->code();
                par.params().labelString(counters.theCounter(enumcounter, lang));

                break;
        }

        case LABEL_SENSITIVE: {
                string const & type = counters.current_float();
                docstring full_label;
                if (type.empty())
                        full_label = owner_->B_("Senseless!!! ");
                else {
                        docstring name = owner_->B_(textclass.floats().getType(type).name());
                        if (counters.hasCounter(from_utf8(type))) {
                                string const & lang = par.getParLanguage(bp)->code();
                                counters.step(from_utf8(type), utype);
                                full_label = bformat(from_ascii("%1$s %2$s:"),
                                                     name,
                                                     counters.theCounter(from_utf8(type), lang));
                        } else
                                full_label = bformat(from_ascii("%1$s #:"), name);
                }
                par.params().labelString(full_label);
                break;
        }

        case LABEL_NO_LABEL:
                par.params().labelString(docstring());
                break;

        case LABEL_ABOVE:
        case LABEL_CENTERED:
        case LABEL_STATIC: {
                docstring const & lcounter = layout.counter;
                if (!lcounter.empty()) {
                        if (layout.toclevel <= bp.secnumdepth
                                                && (layout.latextype != LATEX_ENVIRONMENT
                                        || it.text()->isFirstInSequence(it.pit()))) {
                                if (counters.hasCounter(lcounter))
                                        counters.step(lcounter, utype);
                                par.params().labelString(par.expandLabel(layout, bp));
                        } else
                                par.params().labelString(docstring());
                } else
                        par.params().labelString(par.expandLabel(layout, bp));
                break;
        }

        case LABEL_MANUAL:
        case LABEL_BIBLIO:
                par.params().labelString(par.expandLabel(layout, bp));
        }
}


void Buffer::updateBuffer(ParIterator & parit, UpdateType utype, bool const deleted) const
{
        pushIncludedBuffer(this);
        // LASSERT: Is it safe to continue here, or should we just return?
        LASSERT(parit.pit() == 0, /**/);

        // Set the position of the text in the buffer to be able
        // to resolve macros in it.
        parit.text()->setMacrocontextPosition(parit);

        depth_type maxdepth = 0;
        pit_type const lastpit = parit.lastpit();
        bool changed = false;
        for ( ; parit.pit() <= lastpit ; ++parit.pit()) {
                // reduce depth if necessary
                if (parit->params().depth() > maxdepth) {
                        /** FIXME: this function is const, but
                         * nevertheless it modifies the buffer. To be
                         * cleaner, one should modify the buffer in
                         * another function, which is actually
                         * non-const. This would however be costly in
                         * terms of code duplication.
                         */
                        CursorData(parit).recordUndo();
                        parit->params().depth(maxdepth);
                }
                maxdepth = parit->getMaxDepthAfter();

                if (utype == OutputUpdate) {
                        // track the active counters
                        // we have to do this for the master buffer, since the local
                        // buffer isn't tracking anything.
                        masterBuffer()->params().documentClass().counters().
                                        setActiveLayout(parit->layout());
                }

                // set the counter for this paragraph
                d->setLabel(parit, utype);

                // now the insets
                for (auto const & insit : parit->insetList()) {
                        parit.pos() = insit.pos;
                        insit.inset->updateBuffer(parit, utype, deleted || parit->isDeleted(insit.pos));
                        changed |= insit.inset->isChanged();
                }

                // are there changes in this paragraph?
                changed |= parit->isChanged();
        }

        // set change indicator for the inset (or the cell that the iterator
        // points to, if applicable).
        parit.text()->inset().isChanged(changed);
        popIncludedBuffer();
}


void Buffer::forceUpdate() const
{
        d->need_update = true;
}


bool Buffer::needUpdate() const
{
        return d->need_update;
}


int Buffer::spellCheck(DocIterator & from, DocIterator & to,
        WordLangTuple & word_lang, docstring_list & suggestions) const
{
        int progress = 0;
        WordLangTuple wl;
        suggestions.clear();
        word_lang = WordLangTuple();
        bool const to_end = to.empty();
        DocIterator const end = to_end ? doc_iterator_end(this) : to;
        // OK, we start from here.
        for (; from != end; from.forwardPos()) {
                // This skips all insets with spell check disabled.
                while (!from.allowSpellCheck()) {
                        from.pop_back();
                        from.pos()++;
                }
                // If from is at the end of the document (which is possible
                // when "from" was changed above) LyX will crash later otherwise.
                if (from.atEnd() || (!to_end && from >= end))
                        break;
                to = from;
                from.paragraph().spellCheck();
                SpellChecker::Result res = from.paragraph().spellCheck(from.pos(), to.pos(), wl, suggestions);
                if (SpellChecker::misspelled(res)) {
                        word_lang = wl;
                        break;
                }
                // Do not increase progress when from == to, otherwise the word
                // count will be wrong.
                if (from != to) {
                        from = to;
                        ++progress;
                }
        }
        return progress;
}


void Buffer::requestSpellcheck()
{
        ParagraphList::iterator pit = paragraphs().begin();
        ParagraphList::iterator pend = paragraphs().end();
        for (; pit != pend; ++pit)
                pit->requestSpellCheck();
}


void Buffer::Impl::updateStatistics(DocIterator & from, DocIterator & to, bool skipNoOutput)
{
        bool inword = false;
        word_count_ = 0;
        char_count_ = 0;
        blank_count_ = 0;

        for (DocIterator dit = from ; dit != to && !dit.atEnd(); ) {
                if (!dit.inTexted()) {
                        dit.forwardPos();
                        continue;
                }

                Paragraph const & par = dit.paragraph();
                pos_type const pos = dit.pos();

                // Copied and adapted from isWordSeparator() in Paragraph
                if (pos == dit.lastpos()) {
                        inword = false;
                } else {
                        Inset const * ins = par.getInset(pos);
                        if (ins && skipNoOutput && !ins->producesOutput()) {
                                // skip this inset
                                ++dit.top().pos();
                                // stop if end of range was skipped
                                if (!to.atEnd() && dit >= to)
                                        break;
                                continue;
                        } else if (!par.isDeleted(pos)) {
                                if (par.isWordSeparator(pos))
                                        inword = false;
                                else if (!inword) {
                                        ++word_count_;
                                        inword = true;
                                }
                                if (ins && ins->isLetter()) {
                                        odocstringstream os;
                                        ins->toString(os);
                                        char_count_ += os.str().length();
                                }
                                else if (ins && ins->isSpace())
                                        ++blank_count_;
                                else if (ins) {
                                        pair<int, int> words = ins->isWords();
                                        char_count_ += words.first;
                                        word_count_ += words.second;
                                        inword = false;
                                }
                                else {
                                        char_type const c = par.getChar(pos);
                                        if (isPrintableNonspace(c))
                                                ++char_count_;
                                        else if (isSpace(c))
                                                ++blank_count_;
                                }
                        }
                }
                dit.forwardPos();
        }
}


void Buffer::updateStatistics(DocIterator & from, DocIterator & to, bool skipNoOutput) const
{
        d->updateStatistics(from, to, skipNoOutput);
}


int Buffer::wordCount() const
{
        return d->wordCount();
}


int Buffer::charCount(bool with_blanks) const
{
        return d->charCount(with_blanks);
}


bool Buffer::areChangesPresent() const
{
        return inset().isChanged();
}


Buffer::ReadStatus Buffer::reload()
{
        setBusy(true);
        // c.f. bug https://www.lyx.org/trac/ticket/6587
        removeAutosaveFile();
        // e.g., read-only status could have changed due to version control
        d->filename.refresh();
        docstring const disp_fn = makeDisplayPath(d->filename.absFileName());

        // clear parent. this will get reset if need be.
        d->setParent(nullptr);
        ReadStatus const status = loadLyXFile();
        if (status == ReadSuccess) {
                updateBuffer();
                changed(true);
                updateTitles();
                markClean();
                message(bformat(_("Document %1$s reloaded."), disp_fn));
                d->undo_.clear();
        } else {
                message(bformat(_("Could not reload document %1$s."), disp_fn));
        }
        setBusy(false);
        removePreviews();
        updatePreviews();
        errors("Parse");
        return status;
}


bool Buffer::saveAs(FileName const & fn)
{
        FileName const old_name = fileName();
        FileName const old_auto = getAutosaveFileName();
        bool const old_unnamed = isUnnamed();
        bool success = true;
        d->old_position = filePath();

        setFileName(fn);
        markDirty();
        setUnnamed(false);

        if (save()) {
                // bring the autosave file with us, just in case.
                moveAutosaveFile(old_auto);
                // validate version control data and
                // correct buffer title
                lyxvc().file_found_hook(fileName());
                updateTitles();
                // the file has now been saved to the new location.
                // we need to check that the locations of child buffers
                // are still valid.
                checkChildBuffers();
                checkMasterBuffer();
        } else {
                // save failed
                // reset the old filename and unnamed state
                setFileName(old_name);
                setUnnamed(old_unnamed);
                success = false;
        }

        d->old_position.clear();
        return success;
}


void Buffer::checkChildBuffers()
{
        for (auto const & bit : d->children_positions) {
                DocIterator dit = bit.second;
                Buffer * cbuf = const_cast<Buffer *>(bit.first);
                if (!cbuf || !theBufferList().isLoaded(cbuf))
                        continue;
                Inset * inset = dit.nextInset();
                LASSERT(inset && inset->lyxCode() == INCLUDE_CODE, continue);
                InsetInclude * inset_inc = static_cast<InsetInclude *>(inset);
                docstring const & incfile = inset_inc->getParam("filename");
                string oldloc = cbuf->absFileName();
                string newloc = makeAbsPath(to_utf8(incfile),
                                onlyPath(absFileName())).absFileName();
                if (oldloc == newloc)
                        continue;
                // the location of the child file is incorrect.
                cbuf->setParent(nullptr);
                inset_inc->setChildBuffer(nullptr);
        }
        // invalidate cache of children
        d->children_positions.clear();
        d->position_to_children.clear();
}


// If a child has been saved under a different name/path, it might have been
// orphaned. Therefore the master needs to be reset (bug 8161).
void Buffer::checkMasterBuffer()
{
        Buffer const * const master = masterBuffer();
        if (master == this)
                return;

        // necessary to re-register the child (bug 5873)
        // FIXME: clean up updateMacros (here, only
        // child registering is needed).
        master->updateMacros();
        // (re)set master as master buffer, but only
        // if we are a real child
        if (master->isChild(this))
                setParent(master);
        else
                setParent(nullptr);
}


string Buffer::includedFilePath(string const & name, string const & ext) const
{
        if (d->old_position.empty() ||
            equivalent(FileName(d->old_position), FileName(filePath())))
                return name;

        bool isabsolute = FileName::isAbsolute(name);
        // both old_position and filePath() end with a path separator
        string absname = isabsolute ? name : d->old_position + name;

        // if old_position is set to origin, we need to do the equivalent of
        // getReferencedFileName() (see readDocument())
        if (!isabsolute && d->old_position == params().origin) {
                FileName const test(addExtension(filePath() + name, ext));
                if (test.exists())
                        absname = filePath() + name;
        }

        if (!FileName(addExtension(absname, ext)).exists())
                return name;

        if (isabsolute)
                return to_utf8(makeRelPath(from_utf8(name), from_utf8(filePath())));

        return to_utf8(makeRelPath(from_utf8(FileName(absname).realPath()),
                                   from_utf8(filePath())));
}


void Buffer::Impl::refreshFileMonitor()
{
        if (file_monitor_ && file_monitor_->filename() == filename.absFileName()) {
                file_monitor_->refresh();
                return;
        }

        // The previous file monitor is invalid
        // This also destroys the previous file monitor and all its connections
        file_monitor_ = FileSystemWatcher::monitor(filename);
        // file_monitor_ will be destroyed with *this, so it is not going to call a
        // destroyed object method.
        file_monitor_->connect([this](bool exists) {
                        fileExternallyModified(exists);
                });
}


void Buffer::Impl::fileExternallyModified(bool const exists)
{
        // ignore notifications after our own saving operations
        if (checksum_ == filename.checksum()) {
                LYXERR(Debug::FILES, "External modification but "
                       "checksum unchanged: " << filename);
                return;
        }
        // If the file has been deleted, only mark the file as dirty since it is
        // pointless to prompt for reloading. If later a file is moved into this
        // location, then the externally modified warning will appear then.
        if (exists)
                        externally_modified_ = true;
        // Update external modification notification.
        // Dirty buffers must be visible at all times.
        if (wa_ && wa_->unhide(owner_))
                wa_->updateTitles();
        else
                // Unable to unhide the buffer (e.g. no GUI or not current View)
                lyx_clean = true;
}


bool Buffer::notifiesExternalModification() const
{
        return d->externally_modified_;
}


void Buffer::clearExternalModification() const
{
        d->externally_modified_ = false;
        if (d->wa_)
                d->wa_->updateTitles();
}


void Buffer::pushIncludedBuffer(Buffer const * buf) const
{
        masterBuffer()->d->include_list_.push_back(buf);
        if (lyxerr.debugging(Debug::FILES)) {
                LYXERR0("Pushed. Stack now:");
                if (masterBuffer()->d->include_list_.empty())
                        LYXERR0("EMPTY!");
                else
                        for (auto const & b : masterBuffer()->d->include_list_)
                                LYXERR0(b->fileName());
        }
}


void Buffer::popIncludedBuffer() const
{
        masterBuffer()->d->include_list_.pop_back();
        if (lyxerr.debugging(Debug::FILES)) {
                LYXERR0("Popped. Stack now:");
                if (masterBuffer()->d->include_list_.empty())
                        LYXERR0("EMPTY!");
                else
                        for (auto const & b : masterBuffer()->d->include_list_)
                                LYXERR0(b->fileName());
        }
}


bool Buffer::isBufferIncluded(Buffer const * buf) const
{
        if (!buf)
                return false;
        if (lyxerr.debugging(Debug::FILES)) {
                LYXERR0("Checking for " << buf->fileName() << ". Stack now:");
                if (masterBuffer()->d->include_list_.empty())
                        LYXERR0("EMPTY!");
                else
                        for (auto const & b : masterBuffer()->d->include_list_)
                                LYXERR0(b->fileName());
        }
        list<Buffer const *> const & blist = masterBuffer()->d->include_list_;
        return find(blist.begin(), blist.end(), buf) != blist.end();
}


void Buffer::clearIncludeList() const
{
        LYXERR(Debug::FILES, "Clearing include list for " << fileName());
        d->include_list_.clear();
}

} // namespace lyx