]> git.lyx.org Git - lyx.git/blobdiff - src/output_latex.cpp
Correctly set language after intitle paragraphs
[lyx.git] / src / output_latex.cpp
index cebc1ed5be9c49781d85c89809c6e94c9ac1f495..4124d2dd1c92fde9f5cf08cb62ca29808ed1277f 100644 (file)
 
 #include "output_latex.h"
 
+#include "BiblioInfo.h"
 #include "Buffer.h"
 #include "BufferParams.h"
 #include "Encoding.h"
 #include "Font.h"
 #include "InsetList.h"
 #include "Language.h"
+#include "LaTeXFeatures.h"
 #include "Layout.h"
 #include "LyXRC.h"
 #include "OutputParams.h"
 #include "Paragraph.h"
 #include "ParagraphParameters.h"
+#include "texstream.h"
 #include "TextClass.h"
-#include "TexRow.h"
-#include "VSpace.h"
 
 #include "insets/InsetBibitem.h"
 #include "insets/InsetArgument.h"
 
+#include "frontends/alert.h"
+
 #include "support/lassert.h"
+#include "support/convert.h"
 #include "support/debug.h"
 #include "support/lstrings.h"
+#include "support/lyxalgo.h"
+#include "support/textutils.h"
+#include "support/gettext.h"
+
+#include <QThreadStorage>
 
-#include <boost/next_prior.hpp>
 #include <list>
+#include <stack>
 
 using namespace std;
 using namespace lyx::support;
@@ -46,14 +55,82 @@ namespace lyx {
 namespace {
 
 enum OpenEncoding {
-               none,
-               inputenc,
-               CJK
+       none,
+       inputenc,
+       CJK
 };
 
-static int open_encoding_ = none;
-static int cjk_inherited_ = 0;
-Language const * prev_env_language_ = 0;
+
+struct OutputState
+{
+       OutputState() : open_encoding_(none), cjk_inherited_(0),
+               prev_env_language_(nullptr), nest_level_(0)
+       {
+       }
+       OpenEncoding open_encoding_;
+       int cjk_inherited_;
+       Language const * prev_env_language_;
+       int nest_level_;
+       stack<int> lang_switch_depth_;          // Both are always empty when
+       stack<string> open_polyglossia_lang_;   // not using polyglossia
+};
+
+
+OutputState * getOutputState()
+{
+       // FIXME An instance of OutputState should be kept around for each export
+       //       instead of using local thread storage
+       static QThreadStorage<OutputState *> outputstate;
+       if (!outputstate.hasLocalData())
+               outputstate.setLocalData(new OutputState);
+       return outputstate.localData();
+}
+
+
+string const & openLanguageName(OutputState const * state)
+{
+       // Return a reference to the last active language opened with
+       // polyglossia or when using begin/end commands. If none or when
+       // using babel with only a begin command, return a reference to
+       // an empty string.
+
+       static string const empty;
+
+       return state->open_polyglossia_lang_.empty()
+               ? empty
+               : state->open_polyglossia_lang_.top();
+}
+
+
+bool atSameLastLangSwitchDepth(OutputState const * state)
+{
+       // Return true if the actual nest level is the same at which the
+       // language was switched when using polyglossia or begin/end
+       // commands. Instead, return always true when using babel with
+       // only a begin command.
+
+       return state->lang_switch_depth_.size() == 0
+                       ? true
+                       : abs(state->lang_switch_depth_.top()) == state->nest_level_;
+}
+
+
+bool isLocalSwitch(OutputState const * state)
+{
+       // Return true if the language was opened by a local command switch.
+
+       return state->lang_switch_depth_.size()
+               && state->lang_switch_depth_.top() < 0;
+}
+
+
+bool langOpenedAtThisLevel(OutputState const * state)
+{
+       // Return true if the language was opened at the current nesting level.
+
+       return state->lang_switch_depth_.size()
+               && abs(state->lang_switch_depth_.top()) == state->nest_level_;
+}
 
 
 string const getPolyglossiaEnvName(Language const * lang)
@@ -66,7 +143,26 @@ string const getPolyglossiaEnvName(Language const * lang)
 }
 
 
-struct TeXEnvironementData
+string const getPolyglossiaBegin(string const & lang_begin_command,
+                                string const & lang, string const & opts,
+                                bool const localswitch = false)
+{
+       string result;
+       if (!lang.empty()) {
+               // we need to revert the upcasing done in getPolyglossiaEnvName()
+               // in case we have a local polyglossia command (\textarabic).
+               string language = localswitch ? ascii_lowercase(lang) : lang;
+               result = subst(lang_begin_command, "$$lang", language);
+       }
+       string options = opts.empty() ?
+                   string() : "[" + opts + "]";
+       result = subst(result, "$$opts", options);
+
+       return result;
+}
+
+
+struct TeXEnvironmentData
 {
        bool cjk_nested;
        Layout const * style;
@@ -76,11 +172,13 @@ struct TeXEnvironementData
 };
 
 
-static TeXEnvironementData prepareEnvironement(Buffer const & buf, Text const & text,
-               ParagraphList::const_iterator pit, odocstream & os, TexRow & texrow,
-               OutputParams const & runparams)
+static TeXEnvironmentData prepareEnvironment(Buffer const & buf,
+                                       Text const & text,
+                                       ParagraphList::const_iterator pit,
+                                       otexstream & os,
+                                       OutputParams const & runparams)
 {
-       TeXEnvironementData data;
+       TeXEnvironmentData data;
 
        BufferParams const & bparams = buf.params();
 
@@ -91,9 +189,10 @@ static TeXEnvironementData prepareEnvironement(Buffer const & buf, Text const &
 
        ParagraphList const & paragraphs = text.paragraphs();
        ParagraphList::const_iterator const priorpit =
-               pit == paragraphs.begin() ? pit : boost::prior(pit);
+               pit == paragraphs.begin() ? pit : prev(pit, 1);
 
-       bool const use_prev_env_language = prev_env_language_ != 0
+       OutputState * state = getOutputState();
+       bool const use_prev_env_language = state->prev_env_language_ != nullptr
                        && priorpit->layout().isEnvironment()
                        && (priorpit->getDepth() > pit->getDepth()
                            || (priorpit->getDepth() == pit->getDepth()
@@ -104,25 +203,28 @@ static TeXEnvironementData prepareEnvironement(Buffer const & buf, Text const &
        Language const * const doc_language = bparams.language;
        Language const * const prev_par_language =
                (pit != paragraphs.begin())
-               ? (use_prev_env_language ? prev_env_language_
+               ? (use_prev_env_language ? state->prev_env_language_
                                         : priorpit->getParLanguage(bparams))
                : doc_language;
-       string par_lang = data.par_language->babel();
-       string prev_par_lang = prev_par_language->babel();
-       string doc_lang = doc_language->babel();
-       string lang_begin_command = lyxrc.language_command_begin;
-       string lang_end_command = lyxrc.language_command_end;
-
-       if (runparams.use_polyglossia) {
-               par_lang = getPolyglossiaEnvName(data.par_language);
-               prev_par_lang = getPolyglossiaEnvName(prev_par_language);
-               doc_lang = getPolyglossiaEnvName(doc_language);
-               lang_begin_command = "\\begin{$$lang}";
-               lang_end_command = "\\end{$$lang}";
-       }
 
+       bool const use_polyglossia = runparams.use_polyglossia;
+       string const par_lang = use_polyglossia ?
+               getPolyglossiaEnvName(data.par_language) : data.par_language->babel();
+       string const prev_par_lang = use_polyglossia ?
+               getPolyglossiaEnvName(prev_par_language) : prev_par_language->babel();
+       string const doc_lang = use_polyglossia ?
+               getPolyglossiaEnvName(doc_language) : doc_language->babel();
+       string const lang_begin_command = use_polyglossia ?
+               "\\begin{$$lang}" : lyxrc.language_command_begin;
+       string const lang_end_command = use_polyglossia ?
+               "\\end{$$lang}" : lyxrc.language_command_end;
+       bool const using_begin_end = use_polyglossia ||
+                                       !lang_end_command.empty();
+
+       // For polyglossia, switch language outside of environment, if possible.
        if (par_lang != prev_par_lang) {
-               if (!lang_end_command.empty() &&
+               if ((!using_begin_end || langOpenedAtThisLevel(state)) &&
+                   !lang_end_command.empty() &&
                    prev_par_lang != doc_lang &&
                    !prev_par_lang.empty()) {
                        os << from_ascii(subst(
@@ -131,24 +233,31 @@ static TeXEnvironementData prepareEnvironement(Buffer const & buf, Text const &
                                prev_par_lang))
                          // the '%' is necessary to prevent unwanted whitespace
                          << "%\n";
-                       texrow.newline();
+                       if (using_begin_end)
+                               popLanguageName();
                }
 
+               // If no language was explicitly opened and we are using
+               // polyglossia or begin/end commands, then the current
+               // language is the document language.
+               string const & cur_lang = using_begin_end
+                                         && state->lang_switch_depth_.size()
+                                                 ? openLanguageName(state)
+                                                 : doc_lang;
+
                if ((lang_end_command.empty() ||
-                   par_lang != doc_lang) &&
+                   par_lang != doc_lang ||
+                   par_lang != cur_lang) &&
                    !par_lang.empty()) {
-                       os << from_ascii(subst(
-                               lang_begin_command,
-                               "$$lang",
-                               par_lang));
-                       if (runparams.use_polyglossia
-                           && !data.par_language->polyglossiaOpts().empty())
-                                       os << "["
-                                          << from_ascii(data.par_language->polyglossiaOpts())
-                                          << "]";
-                         // the '%' is necessary to prevent unwanted whitespace
-                       os << "%\n";
-                       texrow.newline();
+                           string bc = use_polyglossia ?
+                                       getPolyglossiaBegin(lang_begin_command, par_lang,
+                                                           data.par_language->polyglossiaOpts())
+                                     : subst(lang_begin_command, "$$lang", par_lang);
+                           os << bc;
+                           // the '%' is necessary to prevent unwanted whitespace
+                           os << "%\n";
+                           if (using_begin_end)
+                                   pushLanguageName(par_lang);
                }
        }
 
@@ -157,18 +266,18 @@ static TeXEnvironementData prepareEnvironement(Buffer const & buf, Text const &
                os << "\\begin{LyXParagraphLeftIndent}{"
                   << from_ascii(pit->params().leftIndent().asLatexString())
                   << "}\n";
-               texrow.newline();
                data.leftindent_open = true;
        }
 
-       if (style.isEnvironment()) {
+       if (style.isEnvironment())
+               state->nest_level_ += 1;
+
+       if (style.isEnvironment() && !style.latexname().empty()) {
                os << "\\begin{" << from_ascii(style.latexname()) << '}';
-               if (style.optargs != 0 || style.reqargs != 0) {
-                       int ret = latexArgInsets(*pit, os, runparams, style.reqargs, style.optargs);
-                       while (ret > 0) {
-                               texrow.newline();
-                               --ret;
-                       }
+               if (!style.latexargs().empty()) {
+                       OutputParams rp = runparams;
+                       rp.local_font = &pit->getFirstFontSettings(bparams);
+                       latexArgInsets(paragraphs, pit, os, rp, style.latexargs());
                }
                if (style.latextype == LATEX_LIST_ENVIRONMENT) {
                        os << '{'
@@ -183,76 +292,107 @@ static TeXEnvironementData prepareEnvironement(Buffer const & buf, Text const &
                                  << "}\n";
                } else
                        os << from_ascii(style.latexparam()) << '\n';
-               texrow.newline();
+               if (style.latextype == LATEX_BIB_ENVIRONMENT
+                   || style.latextype == LATEX_ITEM_ENVIRONMENT
+                   || style.latextype ==  LATEX_LIST_ENVIRONMENT) {
+                       OutputParams rp = runparams;
+                       rp.local_font = &pit->getFirstFontSettings(bparams);
+                       latexArgInsets(paragraphs, pit, os, rp, style.listpreamble(),
+                                      "listpreamble:");
+               }
        }
        data.style = &style;
 
        // in multilingual environments, the CJK tags have to be nested properly
        data.cjk_nested = false;
-       if (data.par_language->encoding()->package() == Encoding::CJK &&
-           open_encoding_ != CJK && pit->isMultiLingual(bparams)) {
-               if (prev_par_language->encoding()->package() == Encoding::CJK)
-                       os << "\\begin{CJK}{" << from_ascii(data.par_language->encoding()->latexName())
+       if (!bparams.useNonTeXFonts
+           && (bparams.inputenc == "auto-legacy"
+                       || bparams.inputenc == "auto-legacy-plain")
+           && data.par_language->encoding()->package() == Encoding::CJK
+           && state->open_encoding_ != CJK && pit->isMultiLingual(bparams)) {
+               if (prev_par_language->encoding()->package() == Encoding::CJK) {
+                       os << "\\begin{CJK}{"
+                          << from_ascii(data.par_language->encoding()->latexName())
                           << "}{" << from_ascii(bparams.fonts_cjk) << "}%\n";
-               open_encoding_ = CJK;
+               }
+               state->open_encoding_ = CJK;
                data.cjk_nested = true;
-               texrow.newline();
        }
        return data;
 }
 
 
-static void finishEnvironement(odocstream & os, TexRow & texrow,
-               OutputParams const & runparams, TeXEnvironementData const & data)
+static void finishEnvironment(otexstream & os, OutputParams const & runparams,
+                             TeXEnvironmentData const & data)
 {
-       if (open_encoding_ == CJK && data.cjk_nested) {
+       OutputState * state = getOutputState();
+       // BufferParams const & bparams = buf.params(); // FIXME: for speedup shortcut below, would require passing of "buf" as argument
+       if (state->open_encoding_ == CJK && data.cjk_nested) {
                // We need to close the encoding even if it does not change
                // to do correct environment nesting
                os << "\\end{CJK}\n";
-               texrow.newline();
-               open_encoding_ = none;
+               state->open_encoding_ = none;
        }
 
        if (data.style->isEnvironment()) {
-               os << "\\end{" << from_ascii(data.style->latexname()) << "}\n";
-               texrow.newline();
-               prev_env_language_ = data.par_language;
+               os << breakln;
+               bool const using_begin_end =
+                       runparams.use_polyglossia ||
+                               !lyxrc.language_command_end.empty();
+               // Close any language opened at this nest level
+               if (using_begin_end) {
+                       while (langOpenedAtThisLevel(state)) {
+                               if (isLocalSwitch(state)) {
+                                       os << "}";
+                               } else {
+                                       os << "\\end{"
+                                          << openLanguageName(state)
+                                          << "}%\n";
+                               }
+                               popLanguageName();
+                       }
+               }
+               state->nest_level_ -= 1;
+               string const & name = data.style->latexname();
+               if (!name.empty())
+                       os << "\\end{" << from_ascii(name) << "}\n";
+               state->prev_env_language_ = data.par_language;
                if (runparams.encoding != data.prev_encoding) {
                        runparams.encoding = data.prev_encoding;
-                       if (!runparams.isFullUnicode())
-                               os << setEncoding(data.prev_encoding->iconvName());
+                       os << setEncoding(data.prev_encoding->iconvName());
                }
        }
 
        if (data.leftindent_open) {
-               os << "\\end{LyXParagraphLeftIndent}\n";
-               texrow.newline();
-               prev_env_language_ = data.par_language;
+               os << breakln << "\\end{LyXParagraphLeftIndent}\n";
+               state->prev_env_language_ = data.par_language;
                if (runparams.encoding != data.prev_encoding) {
                        runparams.encoding = data.prev_encoding;
-                       if (!runparams.isFullUnicode())
-                               os << setEncoding(data.prev_encoding->iconvName());
+                       os << setEncoding(data.prev_encoding->iconvName());
                }
        }
+
+       // Check whether we should output a blank line after the environment
+       if (!data.style->nextnoindent)
+               os << '\n';
 }
 
 
-void TeXEnvironment(Buffer const & buf,
-              Text const & text, OutputParams const & runparams,
-                  pit_type & pit, odocstream & os, TexRow & texrow)
+void TeXEnvironment(Buffer const & buf, Text const & text,
+                   OutputParams const & runparams,
+                   pit_type & pit, otexstream & os)
 {
        ParagraphList const & paragraphs = text.paragraphs();
-       ParagraphList::const_iterator par = paragraphs.constIterator(pit);
+       ParagraphList::const_iterator ipar = paragraphs.constIterator(pit);
        LYXERR(Debug::LATEX, "TeXEnvironment for paragraph " << pit);
 
-       Layout const & current_layout = par->layout();
-       depth_type const current_depth = par->params().depth();
-       Length const & current_left_indent = par->params().leftIndent();
+       Layout const & current_layout = ipar->layout();
+       depth_type const current_depth = ipar->params().depth();
+       Length const & current_left_indent = ipar->params().leftIndent();
 
        // This is for debugging purpose at the end.
        pit_type const par_begin = pit;
        for (; pit < runparams.par_end; ++pit) {
-       
                ParagraphList::const_iterator par = paragraphs.constIterator(pit);
 
                // check first if this is an higher depth paragraph.
@@ -272,7 +412,7 @@ void TeXEnvironment(Buffer const & buf,
                        && par->params().depth() == current_depth
                        && par->params().leftIndent() == current_left_indent) {
                        // We are still in the same environment so TeXOnePar and continue;
-                       TeXOnePar(buf, text, pit, os, texrow, runparams);
+                       TeXOnePar(buf, text, pit, os, runparams);
                        continue;
                }
 
@@ -281,23 +421,6 @@ void TeXEnvironment(Buffer const & buf,
                // Or     par->params().depth() > current_depth
                // Or     par->params().leftIndent() != current_left_indent)
 
-               if (par->layout().isParagraph()) {
-                       // FIXME (Lgb): How to handle this? 
-                       //&& !suffixIs(os, "\n\n")
-
-                       // (ARRae) There should be at least one '\n' already but we need there to
-                       // be two for Standard paragraphs that are depth-increment'ed to be
-                       // output correctly. However, tables can also be paragraphs so
-                       // don't adjust them.
-                       // 
-
-                       // FIXME (Lgb): Will it ever harm to have one '\n' too
-                       // many? i.e. that we sometimes will have
-                       // three in a row.
-                       os << '\n';
-                       texrow.newline();
-               }
-
                // FIXME This test should not be necessary.
                // We should perhaps issue an error if it is.
                bool const force_plain_layout = text.inset().forcePlainLayout();
@@ -307,98 +430,316 @@ void TeXEnvironment(Buffer const & buf,
 
                if (!style.isEnvironment()) {
                        // This is a standard paragraph, no need to call TeXEnvironment.
-                       TeXOnePar(buf, text, pit, os, texrow, runparams);
+                       TeXOnePar(buf, text, pit, os, runparams);
                        continue;
                }
 
                // This is a new environment.
-               TeXEnvironementData const data = prepareEnvironement(buf, text, par,
-                       os, texrow, runparams);
+               TeXEnvironmentData const data =
+                       prepareEnvironment(buf, text, par, os, runparams);
                // Recursive call to TeXEnvironment!
-               TeXEnvironment(buf, text, runparams, pit, os, texrow);
-               finishEnvironement(os, texrow, runparams, data);
+               TeXEnvironment(buf, text, runparams, pit, os);
+               finishEnvironment(os, runparams, data);
        }
 
        if (pit != runparams.par_end)
                LYXERR(Debug::LATEX, "TeXEnvironment for paragraph " << par_begin << " done.");
 }
 
-} // namespace anon
-
 
-int latexArgInsets(Paragraph const & par, odocstream & os,
-       OutputParams const & runparams, unsigned int reqargs,
-       unsigned int optargs)
+void getArgInsets(otexstream & os, OutputParams const & runparams, Layout::LaTeXArgMap const & latexargs,
+                 map<int, lyx::InsetArgument const *> ilist, vector<string> required, string const & prefix)
 {
-       unsigned int totalargs = reqargs + optargs;
-       list<InsetArgument const *> ilist;
-
-       InsetList::const_iterator it = par.insetList().begin();
-       InsetList::const_iterator end = par.insetList().end();
-       for (; it != end; ++it) {
-               if (it->inset->lyxCode() == ARG_CODE) {
-                       if (ilist.size() >= totalargs) {
-                               LYXERR0("WARNING: Found extra argument inset.");
-                               continue;
+       unsigned int const argnr = latexargs.size();
+       if (argnr == 0)
+               return;
+
+       // Default and preset args are always output, so if they require
+       // other arguments, consider this.
+       for (auto const & larg : latexargs) {
+               Layout::latexarg const & arg = larg.second;
+               if ((!arg.presetarg.empty() || !arg.defaultarg.empty()) && !arg.requires.empty()) {
+                               vector<string> req = getVectorFromString(arg.requires);
+                               required.insert(required.end(), req.begin(), req.end());
+                       }
+       }
+
+       for (unsigned int i = 1; i <= argnr; ++i) {
+               map<int, InsetArgument const *>::const_iterator lit = ilist.find(i);
+               bool inserted = false;
+               if (lit != ilist.end()) {
+                       InsetArgument const * ins = (*lit).second;
+                       if (ins) {
+                               Layout::LaTeXArgMap::const_iterator const lait =
+                                               latexargs.find(ins->name());
+                               if (lait != latexargs.end()) {
+                                       Layout::latexarg arg = (*lait).second;
+                                       docstring ldelim;
+                                       docstring rdelim;
+                                       if (!arg.nodelims) {
+                                               ldelim = arg.mandatory ?
+                                                       from_ascii("{") : from_ascii("[");
+                                               rdelim = arg.mandatory ?
+                                                       from_ascii("}") : from_ascii("]");
+                                       }
+                                       if (!arg.ldelim.empty())
+                                               ldelim = arg.ldelim;
+                                       if (!arg.rdelim.empty())
+                                               rdelim = arg.rdelim;
+                                       ins->latexArgument(os, runparams, ldelim, rdelim, arg.presetarg);
+                                       if (prefix == "listpreamble:")
+                                               os << breakln;
+                                       inserted = true;
+                               }
                        }
-                       InsetArgument const * ins =
-                               static_cast<InsetArgument const *>(it->inset);
-                       ilist.push_back(ins);
                }
+               if (!inserted) {
+                       Layout::LaTeXArgMap::const_iterator lait = latexargs.begin();
+                       Layout::LaTeXArgMap::const_iterator const laend = latexargs.end();
+                       for (; lait != laend; ++lait) {
+                               string const name = prefix + convert<string>(i);
+                               if ((*lait).first == name) {
+                                       Layout::latexarg arg = (*lait).second;
+                                       docstring preset = arg.presetarg;
+                                       if (!arg.defaultarg.empty()) {
+                                               if (!preset.empty())
+                                                       preset += ",";
+                                               preset += arg.defaultarg;
+                                       }
+                                       if (arg.mandatory) {
+                                               docstring ldelim = arg.ldelim.empty() ?
+                                                               from_ascii("{") : arg.ldelim;
+                                               docstring rdelim = arg.rdelim.empty() ?
+                                                               from_ascii("}") : arg.rdelim;
+                                               os << ldelim << preset << rdelim;
+                                       } else if (!preset.empty()) {
+                                               docstring ldelim = arg.ldelim.empty() ?
+                                                               from_ascii("[") : arg.ldelim;
+                                               docstring rdelim = arg.rdelim.empty() ?
+                                                               from_ascii("]") : arg.rdelim;
+                                               os << ldelim << preset << rdelim;
+                                       } else if (find(required.begin(), required.end(),
+                                                  (*lait).first) != required.end()) {
+                                               docstring ldelim = arg.ldelim.empty() ?
+                                                               from_ascii("[") : arg.ldelim;
+                                               docstring rdelim = arg.rdelim.empty() ?
+                                                               from_ascii("]") : arg.rdelim;
+                                               os << ldelim << rdelim;
+                                       } else
+                                               break;
+                               }
+                       }
+               }
+       }
+       if (runparams.for_search) {
+               // Mark end of arguments for findadv() only
+               os << "\\endarguments{}";
        }
+}
+
 
-       if (!reqargs && ilist.size() == 0)
-               return 0;
-
-       int lines = 0;
-       bool const have_optional_args = ilist.size() > reqargs;
-       if (have_optional_args) {
-               unsigned int todo = ilist.size() - reqargs;
-               for (unsigned int i = 0; i < todo; ++i) {
-                       InsetArgument const * ins = ilist.front();
-                       ilist.pop_front();
-                       lines += ins->latexArgument(os, runparams, true);
+} // namespace
+
+
+void pushLanguageName(string const & lang_name, bool localswitch)
+{
+       OutputState * state = getOutputState();
+
+       int nest_level = localswitch ? -state->nest_level_ : state->nest_level_;
+       state->lang_switch_depth_.push(nest_level);
+       state->open_polyglossia_lang_.push(lang_name);
+}
+
+
+void popLanguageName()
+{
+       OutputState * state = getOutputState();
+
+       state->lang_switch_depth_.pop();
+       state->open_polyglossia_lang_.pop();
+}
+
+
+string const & openLanguageName()
+{
+       OutputState * state = getOutputState();
+
+       return openLanguageName(state);
+}
+
+
+namespace {
+
+void addArgInsets(Paragraph const & par, string const & prefix,
+                 Layout::LaTeXArgMap const & latexargs,
+                 map<int, InsetArgument const *> & ilist,
+                 vector<string> & required)
+{
+       for (auto const & table : par.insetList()) {
+               InsetArgument const * arg = table.inset->asInsetArgument();
+               if (!arg)
+                       continue;
+               if (arg->name().empty()) {
+                       LYXERR0("Error: Unnamed argument inset!");
+                       continue;
+               }
+               string const name = prefix.empty() ?
+                       arg->name() : split(arg->name(), ':');
+               // why converting into an integer?
+               unsigned int const nr = convert<unsigned int>(name);
+               if (ilist.find(nr) == ilist.end())
+                       ilist[nr] = arg;
+               Layout::LaTeXArgMap::const_iterator const lit =
+                       latexargs.find(arg->name());
+               if (lit != latexargs.end()) {
+                       Layout::latexarg const & larg = lit->second;
+                       vector<string> req = getVectorFromString(larg.requires);
+                       move(req.begin(), req.end(), back_inserter(required));
                }
        }
+}
 
-       // we should now have no more insets than there are required
-       // arguments.
-       LASSERT(ilist.size() <= reqargs, /* */);
-       if (!reqargs)
-               return lines;
+} // namespace
+
+
+void latexArgInsets(Paragraph const & par, otexstream & os,
+                    OutputParams const & runparams,
+                    Layout::LaTeXArgMap const & latexargs,
+                    string const & prefix)
+{
+       map<int, InsetArgument const *> ilist;
+       vector<string> required;
+       addArgInsets(par, prefix, latexargs, ilist, required);
+       getArgInsets(os, runparams, latexargs, ilist, required, prefix);
+}
+
+
+void latexArgInsets(ParagraphList const & pars,
+                    ParagraphList::const_iterator pit,
+                    otexstream & os, OutputParams const & runparams,
+                    Layout::LaTeXArgMap const & latexargs,
+                    string const & prefix)
+{
+       map<int, InsetArgument const *> ilist;
+       vector<string> required;
+
+       depth_type const current_depth = pit->params().depth();
+       Layout const current_layout = pit->layout();
+
+       // get the first paragraph in sequence with this layout and depth
+       pit_type offset = 0;
+       while (true) {
+               if (lyx::prev(pit, offset) == pars.begin())
+                       break;
+               ParagraphList::const_iterator priorpit = lyx::prev(pit, offset + 1);
+               if (priorpit->layout() == current_layout
+                   && priorpit->params().depth() == current_depth)
+                       ++offset;
+               else
+                       break;
+       }
+
+       ParagraphList::const_iterator spit = lyx::prev(pit, offset);
+
+       for (; spit != pars.end(); ++spit) {
+               if (spit->layout() != current_layout ||
+                   spit->params().depth() < current_depth)
+                       break;
+               if (spit->params().depth() > current_depth)
+                       continue;
+               addArgInsets(*spit, prefix, latexargs, ilist, required);
+       }
+       getArgInsets(os, runparams, latexargs, ilist, required, prefix);
+}
+
+
+void latexArgInsetsForParent(ParagraphList const & pars, otexstream & os,
+                             OutputParams const & runparams,
+                             Layout::LaTeXArgMap const & latexargs,
+                             string const & prefix)
+{
+       map<int, InsetArgument const *> ilist;
+       vector<string> required;
+
+       for (Paragraph const & par : pars) {
+               if (par.layout().hasArgs())
+                       // The InsetArguments inside this paragraph refer to this paragraph
+                       continue;
+               addArgInsets(par, prefix, latexargs, ilist, required);
+       }
+       getArgInsets(os, runparams, latexargs, ilist, required, prefix);
+}
+
+
+namespace {
+
+// output the proper paragraph start according to latextype.
+void parStartCommand(Paragraph const & par, otexstream & os,
+                    OutputParams const & runparams, Layout const & style)
+{
+       switch (style.latextype) {
+       case LATEX_COMMAND:
+               if (par.needsCProtection(runparams.moving_arg)) {
+                       if (contains(runparams.active_chars, '^'))
+                               // cprotect relies on ^ being on catcode 7
+                               os << "\\begingroup\\catcode`\\^=7";
+                       os << "\\cprotect";
+               }
+               os << '\\' << from_ascii(style.latexname());
 
-       for (unsigned int i = 0; i < reqargs; ++i) {
-               if (ilist.empty())
-                       // a required argument wasn't given, so we output {}
-                       os << "{}";
+               // Command arguments
+               if (!style.latexargs().empty())
+                       latexArgInsets(par, os, runparams, style.latexargs());
+               os << from_ascii(style.latexparam());
+               break;
+       case LATEX_ITEM_ENVIRONMENT:
+       case LATEX_LIST_ENVIRONMENT:
+               if (runparams.for_search) {
+                       os << "\\" + style.itemcommand() << "{" << style.latexname() << "}";
+               }
                else {
-                       InsetArgument const * ins = ilist.front();
-                       ilist.pop_front();
-                       lines += ins->latexArgument(os, runparams, false);
+                       os << "\\" + style.itemcommand();
+                       // Item arguments
+                       if (!style.itemargs().empty())
+                               latexArgInsets(par, os, runparams, style.itemargs(), "item:");
+                       os << " ";
+               }
+               break;
+       case LATEX_ENVIRONMENT:
+               if (runparams.for_search) {
+                       os << "\\latexenvironment{" << style.latexname() << "}{";
                }
+               break;
+       case LATEX_BIB_ENVIRONMENT:
+               // ignore this, the inset will write itself
+               break;
+       default:
+               break;
        }
-       return lines;
 }
 
+} // namespace
 
 // FIXME: this should be anonymous
 void TeXOnePar(Buffer const & buf,
-         Text const & text,
-         pit_type pit,
-         odocstream & os, TexRow & texrow,
-         OutputParams const & runparams_in,
-         string const & everypar,
-         int start_pos, int end_pos)
+              Text const & text,
+              pit_type pit,
+              otexstream & os,
+              OutputParams const & runparams_in,
+              string const & everypar,
+              int start_pos, int end_pos,
+              bool const force)
 {
-       BufferParams const & bparams = buf.params();
+       BufferParams const & bparams = runparams_in.is_child
+               ? buf.masterParams() : buf.params();
        ParagraphList const & paragraphs = text.paragraphs();
        Paragraph const & par = paragraphs.at(pit);
        // FIXME This check should not really be needed.
        // Perhaps we should issue an error if it is.
-       Layout const style = text.inset().forcePlainLayout() ?
+       Layout const style = text.inset().forcePlainLayout() ?
                bparams.documentClass().plainLayout() : par.layout();
 
-       if (style.inpreamble)
+       if (style.inpreamble && !force)
                return;
 
        LYXERR(Debug::LATEX, "TeXOnePar for paragraph " << pit << " ptr " << &par << " '"
@@ -406,7 +747,7 @@ void TeXOnePar(Buffer const & buf,
 
        OutputParams runparams = runparams_in;
        runparams.isLastPar = (pit == pit_type(paragraphs.size() - 1));
-       // We reinitialze par begin and end to be on the safe side
+       // We reinitialize par begin and end to be on the safe side
        // with embedded inset as we don't know if they set those
        // value correctly.
        runparams.par_begin = 0;
@@ -415,49 +756,65 @@ void TeXOnePar(Buffer const & buf,
        bool const maintext = text.isMainText();
        // we are at the beginning of an inset and CJK is already open;
        // we count inheritation levels to get the inset nesting right.
+       OutputState * state = getOutputState();
        if (pit == 0 && !maintext
-           && (cjk_inherited_ > 0 || open_encoding_ == CJK)) {
-               cjk_inherited_ += 1;
-               open_encoding_ = none;
+           && (state->cjk_inherited_ > 0 || state->open_encoding_ == CJK)) {
+               state->cjk_inherited_ += 1;
+               state->open_encoding_ = none;
        }
 
-       if (text.inset().getLayout().isPassThru()) {
+       if (text.inset().isPassThru()) {
                Font const outerfont = text.outerFont(pit);
 
                // No newline before first paragraph in this lyxtext
-               if (pit > 0) {
+               if (pit > 0 && !text.inset().getLayout().parbreakIgnored()) {
                        os << '\n';
-                       texrow.newline();
-                       if (!text.inset().getLayout().parbreakIsNewline()) {
+                       if (!text.inset().getLayout().parbreakIsNewline())
                                os << '\n';
-                               texrow.newline();
-                       }
                }
 
-               par.latex(bparams, outerfont, os, texrow, runparams, start_pos,
-                       end_pos);
+               par.latex(bparams, outerfont, os, runparams, start_pos, end_pos, force);
                return;
        }
 
        Paragraph const * nextpar = runparams.isLastPar
-               ? 0 : &paragraphs.at(pit + 1);
+               ? nullptr : &paragraphs.at(pit + 1);
+
+       bool const intitle_command = style.intitle && style.isCommand();
 
        if (style.pass_thru) {
                Font const outerfont = text.outerFont(pit);
-               par.latex(bparams, outerfont, os, texrow, runparams, start_pos,
-                       end_pos);
-               os << '\n';
-               texrow.newline();
+               parStartCommand(par, os, runparams, style);
+               if (style.isCommand() && style.needprotect)
+                       // Due to the moving argument, some fragile
+                       // commands (labels, index entries)
+                       // are output after this command (#2154)
+                       runparams.postpone_fragile_stuff = true;
+               if (intitle_command)
+                       os << '{';
+
+               par.latex(bparams, outerfont, os, runparams, start_pos, end_pos, force);
+
+               // I did not create a parEndCommand for this minuscule
+               // task because in the other user of parStartCommand
+               // the code is different (JMarc)
+               if (style.isCommand()) {
+                       os << "}";
+                       if (par.needsCProtection(runparams.moving_arg)
+                           && contains(runparams.active_chars, '^'))
+                               os << "\\endgroup";
+                       os << "\n";
+               }
+               else
+                       os << '\n';
                if (!style.parbreak_is_newline) {
                        os << '\n';
-                       texrow.newline();
-               } else if (nextpar) {
-                       Layout const nextstyle = text.inset().forcePlainLayout() ?
-                               bparams.documentClass().plainLayout() : nextpar->layout();
-                       if (nextstyle.name() != style.name()) {
+               } else if (nextpar && !style.isEnvironment()) {
+                       Layout const nextstyle = text.inset().forcePlainLayout()
+                               ? bparams.documentClass().plainLayout()
+                               : nextpar->layout();
+                       if (nextstyle.name() != style.name())
                                os << '\n';
-                               texrow.newline();
-                       }
                }
 
                return;
@@ -465,65 +822,129 @@ void TeXOnePar(Buffer const & buf,
 
        // This paragraph's language
        Language const * const par_language = par.getParLanguage(bparams);
+       Language const * const nextpar_language = nextpar ?
+               nextpar->getParLanguage(bparams) : nullptr;
        // The document's language
        Language const * const doc_language = bparams.language;
        // The language that was in effect when the environment this paragraph is
        // inside of was opened
        Language const * const outer_language =
-               (runparams.local_font != 0) ?
+               (runparams.local_font != nullptr) ?
                        runparams.local_font->language() : doc_language;
 
-       Paragraph const * priorpar = (pit == 0) ? 0 : &paragraphs.at(pit - 1);
+       Paragraph const * priorpar = (pit == 0) ? nullptr : &paragraphs.at(pit - 1);
 
        // The previous language that was in effect is the language of the
        // previous paragraph, unless the previous paragraph is inside an
        // environment with nesting depth greater than (or equal to, but with
        // a different layout) the current one. If there is no previous
        // paragraph, the previous language is the outer language.
-       bool const use_prev_env_language = prev_env_language_ != 0
+       // Note further that we take the outer language also if the prior par
+       // is PassThru, since in that case it has latex_language, and all secondary
+       // languages have been closed (#10793).
+       bool const use_prev_env_language = state->prev_env_language_ != nullptr
                        && priorpar
                        && priorpar->layout().isEnvironment()
                        && (priorpar->getDepth() > par.getDepth()
                            || (priorpar->getDepth() == par.getDepth()
-                                   && priorpar->layout() != par.layout()));
+                               && priorpar->layout() != par.layout()));
+
+       // We need to ignore previous intitle commands since languages
+       // are switched locally there (# 11514)
+       // There might be paragraphs before the title, so we check this.
+       Paragraph * prior_nontitle_par = nullptr;
+       if (!intitle_command) {
+               pit_type ppit = pit;
+               while (ppit > 0) {
+                       --ppit;
+                       Paragraph const * tmppar = &paragraphs.at(ppit);
+                       if (tmppar->layout().intitle && tmppar->layout().isCommand())
+                               continue;
+                       prior_nontitle_par = const_cast<Paragraph*>(tmppar);
+                       break;
+               }
+       }
        Language const * const prev_language =
-               (pit != 0)
-               ? (use_prev_env_language ? prev_env_language_
-                                        : priorpar->getParLanguage(bparams))
-               : outer_language;
-
-       string par_lang = par_language->babel();
-       string prev_lang = prev_language->babel();
-       string doc_lang = doc_language->babel();
-       string outer_lang = outer_language->babel();
-       string lang_begin_command = lyxrc.language_command_begin;
-       string lang_end_command = lyxrc.language_command_end;
-
-       if (runparams.use_polyglossia) {
-               par_lang = getPolyglossiaEnvName(par_language);
-               prev_lang = getPolyglossiaEnvName(prev_language);
-               doc_lang = getPolyglossiaEnvName(doc_language);
-               outer_lang = getPolyglossiaEnvName(outer_language);
-               lang_begin_command = "\\begin{$$lang}";
-               lang_end_command = "\\end{$$lang}";
+               runparams_in.for_search 
+                       ? languages.getLanguage("ignore")
+                       : (prior_nontitle_par && !prior_nontitle_par->isPassThru())
+                               ? (use_prev_env_language 
+                                       ? state->prev_env_language_
+                                       : prior_nontitle_par->getParLanguage(bparams))
+                               : outer_language;
+
+       bool const use_polyglossia = runparams.use_polyglossia;
+       string const par_lang = use_polyglossia ?
+               getPolyglossiaEnvName(par_language): par_language->babel();
+       string const prev_lang = use_polyglossia ?
+               getPolyglossiaEnvName(prev_language) : prev_language->babel();
+       string const outer_lang = use_polyglossia ?
+               getPolyglossiaEnvName(outer_language) : outer_language->babel();
+       string const nextpar_lang = nextpar_language ? (use_polyglossia ?
+               getPolyglossiaEnvName(nextpar_language) :
+               nextpar_language->babel()) : string();
+       string lang_begin_command = use_polyglossia ?
+               "\\begin{$$lang}$$opts" : lyxrc.language_command_begin;
+       string lang_end_command = use_polyglossia ?
+               "\\end{$$lang}" : lyxrc.language_command_end;
+       // the '%' is necessary to prevent unwanted whitespace
+       string lang_command_termination = "%\n";
+       bool const using_begin_end = use_polyglossia ||
+                                       !lang_end_command.empty();
+
+       // For InTitle commands, we need to switch the language inside the command
+       // (see #10849); thus open the command here.
+       if (intitle_command) {
+               parStartCommand(par, os, runparams, style);
+               if (style.isCommand() && style.needprotect)
+                       // Due to the moving argument, some fragile
+                       // commands (labels, index entries)
+                       // are output after this command (#2154)
+                       runparams.postpone_fragile_stuff = true;
+               os << '{';
        }
-       if (par_lang != prev_lang
-               // check if we already put language command in TeXEnvironment()
-               && !(style.isEnvironment()
-                    && (pit == 0 || (priorpar->layout() != par.layout()
-                                         && priorpar->getDepth() <= par.getDepth())
-                                 || priorpar->getDepth() < par.getDepth())))
-       {
-               if (!lang_end_command.empty() &&
-                   prev_lang != outer_lang &&
-                   !prev_lang.empty())
-               {
+
+       // In some insets (such as Arguments), we cannot use \selectlanguage.
+       // Also, if an RTL language is set via environment in polyglossia,
+       // only a nested \\text<lang> command will reset the direction for LTR
+       // languages (see # 10111).
+       bool const in_polyglossia_rtl_env =
+               use_polyglossia
+               && runparams.local_font != nullptr
+               && outer_language->rightToLeft()
+               && !par_language->rightToLeft();
+       bool const localswitch = runparams_in.for_search
+                       || text.inset().forceLocalFontSwitch()
+                       || (using_begin_end && text.inset().forcePlainLayout())
+                       || in_polyglossia_rtl_env;
+       if (localswitch) {
+               lang_begin_command = use_polyglossia ?
+                           "\\text$$lang$$opts{" : lyxrc.language_command_local;
+               lang_end_command = "}";
+               lang_command_termination.clear();
+       }
+
+       bool const localswitch_needed = localswitch && par_lang != outer_lang;
+
+       // localswitches need to be closed and reopened at each par
+       if (runparams_in.for_search || ((par_lang != prev_lang || localswitch_needed)
+            // check if we already put language command in TeXEnvironment()
+            && !(style.isEnvironment()
+                 && (pit == 0 || (priorpar->layout() != par.layout()
+                                  && priorpar->getDepth() <= par.getDepth())
+                     || priorpar->getDepth() < par.getDepth())))) {
+               if (!localswitch
+                   && (!using_begin_end || langOpenedAtThisLevel(state))
+                   && !lang_end_command.empty()
+                   && prev_lang != outer_lang
+                   && !prev_lang.empty()
+                   && (!using_begin_end || !style.isEnvironment())) {
                        os << from_ascii(subst(lang_end_command,
-                               "$$lang",
-                               prev_lang))
-                          // the '%' is necessary to prevent unwanted whitespace
-                          << "%\n";
-                       texrow.newline();
+                                              "$$lang",
+                                              prev_lang))
+                          << lang_command_termination;
+                       if (using_begin_end)
+                               popLanguageName();
                }
 
                // We need to open a new language if we couldn't close the previous
@@ -531,19 +952,21 @@ void TeXOnePar(Buffer const & buf,
                // the previous one, if the current language is different than the
                // outer_language (which is currently in effect once the previous one
                // is closed).
-               if ((lang_end_command.empty() || par_lang != outer_lang)
+               if ((lang_end_command.empty() || par_lang != outer_lang
+                    || (!using_begin_end
+                        || (style.isEnvironment() && par_lang != prev_lang)))
                        && !par_lang.empty()) {
                        // If we're inside an inset, and that inset is within an \L or \R
                        // (or equivalents), then within the inset, too, any opposite
                        // language paragraph should appear within an \L or \R (in addition
                        // to, outside of, the normal language switch commands).
                        // This behavior is not correct for ArabTeX, though.
-                       if (!runparams.use_polyglossia
+                       if (!using_begin_end
                            // not for ArabTeX
-                               && par_language->lang() != "arabic_arabtex"
-                               && outer_language->lang() != "arabic_arabtex"
+                           && par_language->lang() != "arabic_arabtex"
+                           && outer_language->lang() != "arabic_arabtex"
                            // are we in an inset?
-                           && runparams.local_font != 0
+                           && runparams.local_font != nullptr
                            // is the inset within an \L or \R?
                            //
                            // FIXME: currently, we don't check this; this means that
@@ -570,27 +993,30 @@ void TeXOnePar(Buffer const & buf,
                                        os << "\\L{";
                        }
                        // With CJK, the CJK tag has to be closed first (see below)
-                       if (runparams.encoding->package() != Encoding::CJK) {
-                               os << from_ascii(subst(
-                                       lang_begin_command,
-                                       "$$lang",
-                                       par_lang));
-                               if (runparams.use_polyglossia
-                                   && !par_language->polyglossiaOpts().empty())
-                                               os << "["
-                                                 << from_ascii(par_language->polyglossiaOpts())
-                                                 << "]";
-                                  // the '%' is necessary to prevent unwanted whitespace
-                               os << "%\n";
-                               texrow.newline();
+                       if ((runparams.encoding->package() != Encoding::CJK
+                                || bparams.useNonTeXFonts
+                                || runparams.for_search)
+                           && (par_lang != openLanguageName(state) || localswitch || intitle_command)
+                           && !par_lang.empty()) {
+                               string bc = use_polyglossia ?
+                                         getPolyglossiaBegin(lang_begin_command, par_lang,
+                                                             par_language->polyglossiaOpts(),
+                                                             localswitch)
+                                         : subst(lang_begin_command, "$$lang", par_lang);
+                               os << bc;
+                               os << lang_command_termination;
+                               if (using_begin_end)
+                                       pushLanguageName(par_lang, localswitch);
                        }
                }
        }
 
-       // Switch file encoding if necessary; no need to do this for "default"
+       // Switch file encoding if necessary; no need to do this for "auto-legacy-plain"
        // encoding, since this only affects the position of the outputted
        // \inputencoding command; the encoding switch will occur when necessary
-       if (bparams.inputenc == "auto"
+       if (bparams.inputenc == "auto-legacy"
+               && !runparams.isFullUnicode() // Xe/LuaTeX use one document-wide encoding  (see also switchEncoding())
+               && runparams.encoding->package() != Encoding::japanese
                && runparams.encoding->package() != Encoding::none) {
                // Look ahead for future encoding changes.
                // We try to output them at the beginning of the paragraph,
@@ -604,7 +1030,7 @@ void TeXOnePar(Buffer const & buf,
                                par.getFontSettings(bparams, i).language()->encoding();
                        if (encoding->package() != Encoding::CJK
                                && runparams.encoding->package() == Encoding::inputenc
-                               && c < 0x80)
+                               && isASCII(c))
                                continue;
                        if (par.isInset(i))
                                break;
@@ -616,32 +1042,30 @@ void TeXOnePar(Buffer const & buf,
                        if (i != 0 && encoding->package() == Encoding::CJK)
                                continue;
 
-                       pair<bool, int> enc_switch = switchEncoding(os, bparams, runparams,
-                               *encoding);
+                       pair<bool, int> enc_switch = switchEncoding(os.os(),
+                                               bparams, runparams, *encoding);
                        // the following is necessary after a CJK environment in a multilingual
                        // context (nesting issue).
                        if (par_language->encoding()->package() == Encoding::CJK
-                               && open_encoding_ != CJK && cjk_inherited_ == 0) {
-                               os << "\\begin{CJK}{" << from_ascii(par_language->encoding()->latexName())
+                               && state->open_encoding_ != CJK && state->cjk_inherited_ == 0) {
+                               os << "\\begin{CJK}{"
+                                  << from_ascii(par_language->encoding()->latexName())
                                   << "}{" << from_ascii(bparams.fonts_cjk) << "}%\n";
-                               open_encoding_ = CJK;
-                               texrow.newline();
+                               state->open_encoding_ = CJK;
                        }
                        if (encoding->package() != Encoding::none && enc_switch.first) {
                                if (enc_switch.second > 0) {
                                        // the '%' is necessary to prevent unwanted whitespace
                                        os << "%\n";
-                                       texrow.newline();
                                }
                                // With CJK, the CJK tag had to be closed first (see above)
-                               if (runparams.encoding->package() == Encoding::CJK) {
-                                       os << from_ascii(subst(
-                                               lang_begin_command,
-                                               "$$lang",
-                                               par_lang))
-                                       // the '%' is necessary to prevent unwanted whitespace
-                                       << "%\n";
-                                       texrow.newline();
+                               if (runparams.encoding->package() == Encoding::CJK
+                                   && par_lang != openLanguageName(state)
+                                   && !par_lang.empty()) {
+                                       os << subst(lang_begin_command, "$$lang", par_lang)
+                                          << lang_command_termination;
+                                       if (using_begin_end)
+                                               pushLanguageName(par_lang, localswitch);
                                }
                                runparams.encoding = encoding;
                        }
@@ -650,70 +1074,55 @@ void TeXOnePar(Buffer const & buf,
        }
 
        runparams.moving_arg |= style.needprotect;
+       if (style.needmboxprotect)
+               ++runparams.inulemcmd;
        Encoding const * const prev_encoding = runparams.encoding;
 
        bool const useSetSpace = bparams.documentClass().provides("SetSpace");
        if (par.allowParagraphCustomization()) {
                if (par.params().startOfAppendix()) {
-                       os << "\\appendix\n";
-                       texrow.newline();
+                       os << "\n\\appendix\n";
                }
 
-               if (!par.params().spacing().isDefault()
-                       && (pit == 0 || !priorpar->hasSameLayout(par)))
-               {
-                       os << from_ascii(par.params().spacing().writeEnvirBegin(useSetSpace))
-                           << '\n';
-                       texrow.newline();
-               }
+               // InTitle commands must use switches (not environments)
+               // inside the commands (see #9332)
+               if (style.intitle) {
+                       if (!par.params().spacing().isDefault())
+                       {
+                               if (runparams.moving_arg)
+                                       os << "\\protect";
+                               os << from_ascii(par.params().spacing().writeCmd(useSetSpace));
+                       }
+               } else {
+                       if (!par.params().spacing().isDefault()
+                               && (pit == 0 || !priorpar->hasSameLayout(par)))
+                       {
+                               os << from_ascii(par.params().spacing().writeEnvirBegin(useSetSpace))
+                                   << '\n';
+                       }
 
-               if (style.isCommand()) {
-                       os << '\n';
-                       texrow.newline();
+                       if (style.isCommand()) {
+                               os << '\n';
+                       }
                }
        }
 
-       switch (style.latextype) {
-       case LATEX_COMMAND:
-               os << '\\' << from_ascii(style.latexname());
-
-               // Separate handling of optional argument inset.
-               if (style.optargs != 0 || style.reqargs != 0) {
-                       int ret = latexArgInsets(par, os, runparams, style.reqargs, style.optargs);
-                       while (ret > 0) {
-                               texrow.newline();
-                               --ret;
-                       }
-               }
-               else
-                       os << from_ascii(style.latexparam());
-               break;
-       case LATEX_ITEM_ENVIRONMENT:
-       case LATEX_LIST_ENVIRONMENT:
-               os << "\\item ";
-               break;
-       case LATEX_BIB_ENVIRONMENT:
-               // ignore this, the inset will write itself
-               break;
-       default:
-               break;
+       // For InTitle commands, we already started the command before
+       // the language switch
+       if (!intitle_command) {
+               parStartCommand(par, os, runparams, style);
+               if (style.isCommand() && style.needprotect)
+                       // Due to the moving argument, some fragile
+                       // commands (labels, index entries)
+                       // are output after this command (#2154)
+                       runparams.postpone_fragile_stuff = true;
        }
 
        Font const outerfont = text.outerFont(pit);
 
        // FIXME UNICODE
        os << from_utf8(everypar);
-       par.latex(bparams, outerfont, os, texrow, runparams, start_pos, end_pos);
-
-       // Make sure that \\par is done with the font of the last
-       // character if this has another size as the default.
-       // This is necessary because LaTeX (and LyX on the screen)
-       // calculates the space between the baselines according
-       // to this font. (Matthias)
-       //
-       // Is this really needed ? (Dekel)
-       // We do not need to use to change the font for the last paragraph
-       // or for a command.
+       par.latex(bparams, outerfont, os, runparams, start_pos, end_pos, force);
 
        Font const font = par.empty()
                 ? par.getLayoutFont(bparams, outerfont)
@@ -721,81 +1130,112 @@ void TeXOnePar(Buffer const & buf,
 
        bool const is_command = style.isCommand();
 
-       if (style.resfont.size() != font.fontInfo().size()
-           && nextpar
-           && !is_command) {
-               os << '{';
-               os << "\\" << from_ascii(font.latexSize()) << " \\par}";
-       } else if (is_command) {
-               os << '}';
-               if (runparams.encoding != prev_encoding) {
-                       runparams.encoding = prev_encoding;
-                       if (!runparams.isFullUnicode())
+       // InTitle commands need to be closed after the language has been closed.
+       if (!intitle_command) {
+               if (is_command) {
+                       os << '}';
+                       if (!style.postcommandargs().empty())
+                               latexArgInsets(par, os, runparams, style.postcommandargs(), "post:");
+                       if (!runparams.post_macro.empty()) {
+                               // Output the stored fragile commands (labels, indices etc.)
+                               // that need to be output after the command with moving argument.
+                               os << runparams.post_macro;
+                               runparams.post_macro.clear();
+                       }
+                       if (par.needsCProtection(runparams.moving_arg)
+                           && contains(runparams.active_chars, '^'))
+                               os << "\\endgroup";
+                       if (runparams.encoding != prev_encoding) {
+                               runparams.encoding = prev_encoding;
                                os << setEncoding(prev_encoding->iconvName());
+                       }
                }
        }
 
        bool pending_newline = false;
+       bool unskip_newline = false;
+       bool close_lang_switch = false;
        switch (style.latextype) {
        case LATEX_ITEM_ENVIRONMENT:
        case LATEX_LIST_ENVIRONMENT:
-               if (nextpar && (par.params().depth() < nextpar->params().depth()))
-                       pending_newline = true;
+               if ((nextpar && par_lang != nextpar_lang
+                            && nextpar->getDepth() == par.getDepth())
+                   || (atSameLastLangSwitchDepth(state) && nextpar
+                           && nextpar->getDepth() < par.getDepth()))
+                       close_lang_switch = using_begin_end;
+               if (nextpar && par.params().depth() < nextpar->params().depth())
+                       pending_newline = !text.inset().getLayout().parbreakIgnored();
                break;
        case LATEX_ENVIRONMENT: {
-               // if its the last paragraph of the current environment
+               // if it's the last paragraph of the current environment
                // skip it otherwise fall through
                if (nextpar
-                       && (nextpar->layout() != par.layout()
-                       || nextpar->params().depth() != par.params().depth()))
+                   && ((nextpar->layout() != par.layout()
+                          || nextpar->params().depth() != par.params().depth())
+                       || (!using_begin_end || par_lang != nextpar_lang)))
+               {
+                       close_lang_switch = using_begin_end;
                        break;
+               }
        }
-
-       // fall through possible
+       // possible
+       // fall through
        default:
-               // we don't need it for the last paragraph!!!
-               if (nextpar)
-                       pending_newline = true;
+               // we don't need it for the last paragraph and in InTitle commands!!!
+               if (nextpar && !intitle_command)
+                       pending_newline = !text.inset().getLayout().parbreakIgnored();
        }
 
-       if (par.allowParagraphCustomization()) {
+       // InTitle commands use switches (not environments) for space settings
+       if (par.allowParagraphCustomization() && !style.intitle) {
                if (!par.params().spacing().isDefault()
                        && (runparams.isLastPar || !nextpar->hasSameLayout(par))) {
-                       if (pending_newline) {
+                       if (pending_newline)
                                os << '\n';
-                               texrow.newline();
-                       }
-                       os << from_ascii(par.params().spacing().writeEnvirEnd(useSetSpace));
+
+                       string const endtag =
+                               par.params().spacing().writeEnvirEnd(useSetSpace);
+                       if (prefixIs(endtag, "\\end{"))
+                               os << breakln;
+
+                       os << from_ascii(endtag);
                        pending_newline = true;
                }
        }
 
-       // Closing the language is needed for the last paragraph; it is also
-       // needed if we're within an \L or \R that we may have opened above (not
-       // necessarily in this paragraph) and are about to close.
-       bool closing_rtl_ltr_environment = !runparams.use_polyglossia
+       // Closing the language is needed for the last paragraph in a given language
+       // as well as for any InTitleCommand (since these set the language locally);
+       // it is also needed if we're within an \L or \R that we may have opened above
+       // (not necessarily in this paragraph) and are about to close.
+       bool closing_rtl_ltr_environment = !using_begin_end
                // not for ArabTeX
                && (par_language->lang() != "arabic_arabtex"
                    && outer_language->lang() != "arabic_arabtex")
-                    // have we opened and \L or \R environment?
-               && runparams.local_font != 0
+               // have we opened an \L or \R environment?
+               && runparams.local_font != nullptr
                && runparams.local_font->isRightToLeft() != par_language->rightToLeft()
                // are we about to close the language?
-               &&((nextpar && par_language->babel() != (nextpar->getParLanguage(bparams))->babel())
-                  || (runparams.isLastPar && par_language->babel() != outer_language->babel()));
-
-       if (closing_rtl_ltr_environment
-               || (runparams.isLastPar && par_language->babel() != outer_language->babel())) {
+               &&((nextpar && par_lang != nextpar_lang)
+                  || (runparams.isLastPar && par_lang != outer_lang));
+
+       if (localswitch_needed
+           || (intitle_command && using_begin_end)
+           || closing_rtl_ltr_environment
+           || (((runparams.isLastPar && !runparams.inbranch) || close_lang_switch)
+               && (par_lang != outer_lang || (using_begin_end
+                                               && style.isEnvironment()
+                                               && par_lang != nextpar_lang)))) {
                // Since \selectlanguage write the language to the aux file,
                // we need to reset the language at the end of footnote or
                // float.
 
-               if (pending_newline) {
+               if (!localswitch && (pending_newline || close_lang_switch))
                        os << '\n';
-                       texrow.newline();
-               }
+
                // when the paragraph uses CJK, the language has to be closed earlier
-               if (font.language()->encoding()->package() != Encoding::CJK) {
+               if ((font.language()->encoding()->package() != Encoding::CJK)
+                       || bparams.useNonTeXFonts
+                       || runparams_in.for_search) {
                        if (lang_end_command.empty()) {
                                // If this is a child, we should restore the
                                // master language after the last paragraph.
@@ -803,68 +1243,132 @@ void TeXOnePar(Buffer const & buf,
                                        (runparams.isLastPar && runparams.master_language)
                                                ? runparams.master_language
                                                : outer_language;
-                               string const current_lang = runparams.use_polyglossia ?
-                                       getPolyglossiaEnvName(current_language)
+                               string const current_lang = use_polyglossia
+                                       getPolyglossiaEnvName(current_language)
                                        : current_language->babel();
-                               if (!current_lang.empty()) {
+                               if (!current_lang.empty()
+                                   && current_lang != openLanguageName(state)) {
+                                       string bc = use_polyglossia ?
+                                                   getPolyglossiaBegin(lang_begin_command, current_lang,
+                                                                       current_language->polyglossiaOpts(),
+                                                                       localswitch)
+                                                 : subst(lang_begin_command, "$$lang", current_lang);
+                                       os << bc;
+                                       pending_newline = !localswitch
+                                                       && !text.inset().getLayout().parbreakIgnored();
+                                       unskip_newline = !localswitch;
+                                       if (using_begin_end)
+                                               pushLanguageName(current_lang, localswitch);
+                               }
+                       } else if ((!using_begin_end ||
+                                   langOpenedAtThisLevel(state)) &&
+                                  !par_lang.empty()) {
+                               // If we are in an environment, we have to
+                               // close the "outer" language afterwards
+                               string const & cur_lang = openLanguageName(state);
+                               if (!style.isEnvironment()
+                                   || (close_lang_switch
+                                       && atSameLastLangSwitchDepth(state)
+                                       && par_lang != outer_lang
+                                       && (par_lang != cur_lang
+                                           || (cur_lang != outer_lang
+                                               && nextpar
+                                               && style != nextpar->layout())))
+                                   || (atSameLastLangSwitchDepth(state)
+                                       && state->lang_switch_depth_.size()
+                                       && cur_lang != par_lang)
+                                   || in_polyglossia_rtl_env)
+                               {
+                                       if (using_begin_end && !localswitch)
+                                               os << breakln;
                                        os << from_ascii(subst(
-                                               lang_begin_command,
+                                               lang_end_command,
                                                "$$lang",
-                                               current_lang));
-                                       pending_newline = true;
+                                               par_lang));
+                                       pending_newline = !localswitch
+                                                       && !text.inset().getLayout().parbreakIgnored();
+                                       unskip_newline = !localswitch;
+                                       if (using_begin_end)
+                                               popLanguageName();
                                }
-                       } else if (!par_lang.empty()) {
-                               os << from_ascii(subst(
-                                       lang_end_command,
-                                       "$$lang",
-                                       par_lang));
-                               pending_newline = true;
                        }
                }
        }
        if (closing_rtl_ltr_environment)
                os << "}";
 
+       // InTitle commands need to be closed after the language has been closed.
+       if (intitle_command) {
+               os << '}';
+               if (!style.postcommandargs().empty())
+                       latexArgInsets(par, os, runparams, style.postcommandargs(), "post:");
+               if (!runparams.post_macro.empty()) {
+                       // Output the stored fragile commands (labels, indices etc.)
+                       // that need to be output after the command with moving argument.
+                       os << runparams.post_macro;
+                       runparams.post_macro.clear();
+               }
+               if (par.needsCProtection(runparams.moving_arg)
+                   && contains(runparams.active_chars, '^'))
+                       os << "\\endgroup";
+               if (runparams.encoding != prev_encoding) {
+                       runparams.encoding = prev_encoding;
+                       os << setEncoding(prev_encoding->iconvName());
+               }
+       }
+
+       bool const last_was_separator =
+               par.size() > 0 && par.isEnvSeparator(par.size() - 1);
+
        if (pending_newline) {
-               os << '\n';
-               texrow.newline();
+               if (unskip_newline)
+                       // prevent unwanted whitespace
+                       os << '%';
+               if (!os.afterParbreak() && !last_was_separator)
+                       os << '\n';
        }
 
        // if this is a CJK-paragraph and the next isn't, close CJK
        // also if the next paragraph is a multilingual environment (because of nesting)
-       if (nextpar
-               && open_encoding_ == CJK
-               && (nextpar->getParLanguage(bparams)->encoding()->package() != Encoding::CJK
-                  || (nextpar->layout().isEnvironment() && nextpar->isMultiLingual(bparams)))
+       if (nextpar && state->open_encoding_ == CJK
+               && bparams.encoding().iconvName() != "UTF-8"
+               && bparams.encoding().package() != Encoding::CJK
+               && (nextpar_language->encoding()->package() != Encoding::CJK
+                       || (nextpar->layout().isEnvironment() && nextpar->isMultiLingual(bparams)))
                // inbetween environments, CJK has to be closed later (nesting!)
                && (!style.isEnvironment() || !nextpar->layout().isEnvironment())) {
                os << "\\end{CJK}\n";
-               open_encoding_ = none;
+               state->open_encoding_ = none;
        }
 
        // If this is the last paragraph, close the CJK environment
-       // if necessary. If it's an environment, we'll have to \end that first.
-       if (runparams.isLastPar && !style.isEnvironment()) {
-               switch (open_encoding_) {
+       // if necessary. If it's an environment or nested in an environment,
+       // we'll have to \end that first.
+       if (runparams.isLastPar && !style.isEnvironment()
+               && par.params().depth() < 1) {
+               switch (state->open_encoding_) {
                        case CJK: {
                                // do nothing at the end of child documents
                                if (maintext && buf.masterBuffer() != &buf)
                                        break;
-                               // end of main text
+                               // end of main text: also insert a \clearpage (see #5386)
                                if (maintext) {
-                                       os << '\n';
-                                       texrow.newline();
-                                       os << "\\end{CJK}\n";
-                                       texrow.newline();
+                                       os << "\n\\clearpage\n\\end{CJK}\n";
                                // end of an inset
                                } else
                                        os << "\\end{CJK}";
-                               open_encoding_ = none;
+                               state->open_encoding_ = none;
                                break;
                        }
                        case inputenc: {
+                               // FIXME: If we are in an inset and the switch happened outside this inset,
+                               // do not switch back at the end of the inset (bug #8479)
+                               // The following attempt does not help with listings-caption in a CJK document:
+                               // if (runparams_in.local_font != 0
+                               //    && runparams_in.encoding == runparams_in.local_font->language()->encoding())
+                               //      break;
                                os << "\\egroup";
-                               open_encoding_ = none;
+                               state->open_encoding_ = none;
                                break;
                        }
                        case none:
@@ -874,15 +1378,15 @@ void TeXOnePar(Buffer const & buf,
                }
        }
 
-       // If this is the last paragraph, and a local_font was set upon entering
-       // the inset, and we're using "auto" or "default" encoding, the encoding
-       // should be set back to that local_font's encoding.
-       // However, do not change the encoding when a fully unicode aware backend
-       // such as XeTeX is used.
-       if (runparams.isLastPar && runparams_in.local_font != 0
+       // Information about local language is stored as a font feature.
+       // If this is the last paragraph of the inset and a local_font was set upon entering
+       // and we are mixing encodings ("auto-legacy" or "auto-legacy-plain" and no XeTeX or LuaTeX),
+       // ensure the encoding is set back to the default encoding of the local language.
+       if (runparams.isLastPar && runparams_in.local_font != nullptr
            && runparams_in.encoding != runparams_in.local_font->language()->encoding()
-           && (bparams.inputenc == "auto" || bparams.inputenc == "default")
-           && (!runparams.isFullUnicode())) {
+           && (bparams.inputenc == "auto-legacy" || bparams.inputenc == "auto-legacy-plain")
+               && !runparams.isFullUnicode()
+          ) {
                runparams_in.encoding = runparams_in.local_font->language()->encoding();
                os << setEncoding(runparams_in.encoding->iconvName());
        }
@@ -890,25 +1394,61 @@ void TeXOnePar(Buffer const & buf,
        else
                runparams_in.encoding = runparams.encoding;
 
+       // Also pass the post_macros upstream
+       runparams_in.post_macro = runparams.post_macro;
+
 
        // we don't need a newline for the last paragraph!!!
        // Note from JMarc: we will re-add a \n explicitly in
        // TeXEnvironment, because it is needed in this case
-       if (nextpar) {
+       if (nextpar && !os.afterParbreak() && !last_was_separator) {
                Layout const & next_layout = nextpar->layout();
-               if (style == next_layout
-                   // no blank lines before environments!
-                   || !next_layout.isEnvironment()
-                   // unless there's a depth change
-                   // FIXME What we really want to do here is put every \begin and \end
-                   // tag on a new line (which was not the case with nested environments).
-                   // But in the present state of play, we don't have access to the
-                   // information whether the current TeX row is empty or not.
-                   // For some ideas about how to fix this, see this thread:
-                   // http://www.mail-archive.com/lyx-devel@lists.lyx.org/msg145787.html
-                   || nextpar->params().depth() != par.params().depth()) {
-                       os << '\n';
-                       texrow.newline();
+               if (!text.inset().getLayout().parbreakIgnored())
+                       // Make sure to start a new line
+                       os << breakln;
+               // A newline '\n' is always output before a command,
+               // so avoid doubling it.
+               if (!next_layout.isCommand()) {
+                       // Here we now try to avoid spurious empty lines by
+                       // outputting a paragraph break only if: (case 1) the
+                       // paragraph style allows parbreaks and no \begin, \end
+                       // or \item tags are going to follow (i.e., if the next
+                       // isn't the first or the current isn't the last
+                       // paragraph of an environment or itemize) and the
+                       // depth and alignment of the following paragraph is
+                       // unchanged, or (case 2) the following is a
+                       // non-environment paragraph whose depth is increased
+                       // but whose alignment is unchanged, or (case 3) the
+                       // paragraph is not an environment and the next one is a
+                       // non-itemize-like env at lower depth, or (case 4) the
+                       // paragraph is a command not followed by an environment
+                       // and the alignment of the current and next paragraph
+                       // is unchanged, or (case 5) the current alignment is
+                       // changed and a standard paragraph follows.
+                       DocumentClass const & tclass = bparams.documentClass();
+                       if ((style == next_layout
+                            && !style.parbreak_is_newline
+                            && !text.inset().getLayout().parbreakIsNewline()
+                            && !text.inset().getLayout().parbreakIgnored()
+                            && style.latextype != LATEX_ITEM_ENVIRONMENT
+                            && style.latextype != LATEX_LIST_ENVIRONMENT
+                            && style.align == par.getAlign(bparams)
+                            && nextpar->getDepth() == par.getDepth()
+                            && nextpar->getAlign(bparams) == par.getAlign(bparams))
+                           || (!next_layout.isEnvironment()
+                               && nextpar->getDepth() > par.getDepth()
+                               && nextpar->getAlign(bparams) == next_layout.align)
+                           || (!style.isEnvironment()
+                               && next_layout.latextype == LATEX_ENVIRONMENT
+                               && nextpar->getDepth() < par.getDepth())
+                           || (style.isCommand()
+                               && !next_layout.isEnvironment()
+                               && style.align == par.getAlign(bparams)
+                               && next_layout.align == nextpar->getAlign(bparams))
+                           || (style.align != par.getAlign(bparams)
+                               && tclass.isDefaultLayout(next_layout))) {
+                               os << '\n';
+                       }
                }
        }
 
@@ -922,51 +1462,72 @@ void TeXOnePar(Buffer const & buf,
 // LaTeX all paragraphs
 void latexParagraphs(Buffer const & buf,
                     Text const & text,
-                    odocstream & os,
-                    TexRow & texrow,
+                    otexstream & os,
                     OutputParams const & runparams,
                     string const & everypar)
 {
+       LASSERT(runparams.par_begin <= runparams.par_end,
+               { os << "% LaTeX Output Error\n"; return; } );
+
        BufferParams const & bparams = buf.params();
+       BufferParams const & mparams = buf.masterParams();
 
        bool const maintext = text.isMainText();
        bool const is_child = buf.masterBuffer() != &buf;
+       bool const multibib_child = maintext && is_child
+                       && mparams.multibib == "child";
+
+       if (multibib_child && mparams.useBiblatex())
+               os << "\\newrefsection";
+       else if (multibib_child && mparams.useBibtopic()
+                && !buf.masterBibInfo().empty()) {
+               os << "\\begin{btUnit}\n";
+               runparams.openbtUnit = true;
+       }
 
        // Open a CJK environment at the beginning of the main buffer
-       // if the document's language is a CJK language
-       // (but not in child documents)
-       if (maintext && !is_child
-           && bparams.encoding().package() == Encoding::CJK) {
-               os << "\\begin{CJK}{" << from_ascii(bparams.encoding().latexName())
-               << "}{" << from_ascii(bparams.fonts_cjk) << "}%\n";
-               texrow.newline();
-               open_encoding_ = CJK;
+       // if the document's main encoding requires the CJK package
+       // or the document encoding is utf8 and the CJK package is required
+       // (but not in child documents or documents using system fonts):
+       OutputState * state = getOutputState();
+       if (maintext && !is_child && !bparams.useNonTeXFonts
+           && (bparams.encoding().package() == Encoding::CJK
+                       || (bparams.encoding().name() == "utf8"
+                               && runparams.use_CJK))
+          ) {
+               docstring const cjkenc = bparams.encoding().iconvName() == "UTF-8"
+                                                                ? from_ascii("UTF8")
+                                                                : from_ascii(bparams.encoding().latexName());
+               os << "\\begin{CJK}{" << cjkenc
+                  << "}{" << from_ascii(bparams.fonts_cjk) << "}%\n";
+               state->open_encoding_ = CJK;
        }
        // if "auto begin" is switched off, explicitly switch the
        // language on at start
-       string const mainlang = runparams.use_polyglossia ?
-               getPolyglossiaEnvName(bparams.language)
+       string const mainlang = runparams.use_polyglossia
+               getPolyglossiaEnvName(bparams.language)
                : bparams.language->babel();
        string const lang_begin_command = runparams.use_polyglossia ?
-               "\\begin{$$lang}" : lyxrc.language_command_begin;
+               "\\begin{$$lang}$$opts" : lyxrc.language_command_begin;
+       string const lang_end_command = runparams.use_polyglossia ?
+               "\\end{$$lang}" : lyxrc.language_command_end;
+       bool const using_begin_end = runparams.use_polyglossia ||
+                                       !lang_end_command.empty();
 
        if (maintext && !lyxrc.language_auto_begin &&
            !mainlang.empty()) {
                // FIXME UNICODE
-               os << from_utf8(subst(lang_begin_command,
-                                       "$$lang",
-                                       mainlang));
-               if (runparams.use_polyglossia
-                   && !bparams.language->polyglossiaOpts().empty())
-                       os << "["
-                           << from_ascii(bparams.language->polyglossiaOpts())
-                           << "]";
+               string bc = runparams.use_polyglossia ?
+                           getPolyglossiaBegin(lang_begin_command, mainlang,
+                                               bparams.language->polyglossiaOpts())
+                         : subst(lang_begin_command, "$$lang", mainlang);
+               os << bc;
                os << '\n';
-               texrow.newline();
+               if (using_begin_end)
+                       pushLanguageName(mainlang);
        }
 
        ParagraphList const & paragraphs = text.paragraphs();
-       LASSERT(runparams.par_begin <= runparams.par_end, /**/);
 
        if (runparams.par_begin == runparams.par_end) {
                // The full doc will be exported but it is easier to just rely on
@@ -978,8 +1539,13 @@ void latexParagraphs(Buffer const & buf,
        pit_type pit = runparams.par_begin;
        // lastpit is for the language check after the loop.
        pit_type lastpit = pit;
+       // variables used in the loop:
+       bool was_title = false;
+       bool already_title = false;
        DocumentClass const & tclass = bparams.documentClass();
 
+       // Did we already warn about inTitle layout mixing? (we only warn once)
+       bool gave_layout_warning = false;
        for (; pit < runparams.par_end; ++pit) {
                lastpit = pit;
                ParagraphList::const_iterator par = paragraphs.constIterator(pit);
@@ -990,20 +1556,25 @@ void latexParagraphs(Buffer const & buf,
                                tclass.plainLayout() : par->layout();
 
                if (layout.intitle) {
-                       if (runparams.didTitle) {
-                               LYXERR0("Error in latexParagraphs: You"
-                                       " should not mix title layouts"
-                                       " with normal ones.");
-                       } else if (!runparams.inTitle) {
-                               runparams.inTitle = true;
+                       if (already_title) {
+                               if (!gave_layout_warning && !runparams.dryrun) {
+                                       gave_layout_warning = true;
+                                       frontend::Alert::warning(_("Error in latexParagraphs"),
+                                                       bformat(_("You are using at least one "
+                                                         "layout (%1$s) intended for the title, "
+                                                         "after using non-title layouts. This "
+                                                         "could lead to missing or incorrect output."
+                                                         ), layout.name()));
+                               }
+                       } else if (!was_title) {
+                               was_title = true;
                                if (tclass.titletype() == TITLE_ENVIRONMENT) {
                                        os << "\\begin{"
                                                        << from_ascii(tclass.titlename())
                                                        << "}\n";
-                                       texrow.newline();
                                }
                        }
-               } else if (runparams.inTitle && !runparams.didTitle) {
+               } else if (was_title && !already_title && !layout.inpreamble) {
                        if (tclass.titletype() == TITLE_ENVIRONMENT) {
                                os << "\\end{" << from_ascii(tclass.titlename())
                                                << "}\n";
@@ -1012,136 +1583,186 @@ void latexParagraphs(Buffer const & buf,
                                os << "\\" << from_ascii(tclass.titlename())
                                                << "\n";
                        }
-                       texrow.newline();
-                       runparams.didTitle = true;
-                       runparams.inTitle = false;
+                       already_title = true;
+                       was_title = false;
                }
 
+               if (layout.isCommand() && !layout.latexname().empty()
+                   && layout.latexname() == bparams.multibib) {
+                       if (runparams.openbtUnit)
+                               os << "\\end{btUnit}\n";
+                       if (!bparams.useBiblatex()
+                           && !buf.masterBibInfo().empty()) {
+                               os << '\n' << "\\begin{btUnit}\n";
+                               runparams.openbtUnit = true;
+                       }
+               }
 
                if (!layout.isEnvironment() && par->params().leftIndent().zero()) {
                        // This is a standard top level paragraph, TeX it and continue.
-                       TeXOnePar(buf, text, pit, os, texrow, runparams, everypar);
+                       TeXOnePar(buf, text, pit, os, runparams, everypar);
                        continue;
                }
-               
-               TeXEnvironementData const data = prepareEnvironement(buf, text, par,
-                       os, texrow, runparams);
+
+               TeXEnvironmentData const data =
+                       prepareEnvironment(buf, text, par, os, runparams);
                // pit can be changed in TeXEnvironment.
-               TeXEnvironment(buf, text, runparams, pit, os, texrow);
-               finishEnvironement(os, texrow, runparams, data);
+               TeXEnvironment(buf, text, runparams, pit, os);
+               finishEnvironment(os, runparams, data);
        }
 
+       // FIXME: uncomment the content or remove this block
        if (pit == runparams.par_end) {
                        // Make sure that the last paragraph is
                        // correctly terminated (because TeXOnePar does
                        // not add a \n in this case)
                        //os << '\n';
-                       //texrow.newline();
        }
 
        // It might be that we only have a title in this document
-       if (runparams.inTitle && !runparams.didTitle) {
+       if (was_title && !already_title) {
                if (tclass.titletype() == TITLE_ENVIRONMENT) {
                        os << "\\end{" << from_ascii(tclass.titlename())
-                           << "}\n";
-               }
-               else {
+                          << "}\n";
+               } else {
                        os << "\\" << from_ascii(tclass.titlename())
-                           << "\n";
-                               }
-               texrow.newline();
+                          << "\n";
+               }
        }
 
+       if (maintext && !is_child && runparams.openbtUnit)
+               os << "\\end{btUnit}\n";
+
        // if "auto end" is switched off, explicitly close the language at the end
-       // but only if the last par is in a babel language
-       string const lang_end_command = runparams.use_polyglossia ?
-               "\\end{$$lang}" : lyxrc.language_command_end;
+       // but only if the last par is in a babel or polyglossia language
+       Language const * const lastpar_language =
+                       paragraphs.at(lastpit).getParLanguage(bparams);
        if (maintext && !lyxrc.language_auto_end && !mainlang.empty() &&
-               paragraphs.at(lastpit).getParLanguage(bparams)->encoding()->package() != Encoding::CJK) {
+               lastpar_language->encoding()->package() != Encoding::CJK) {
                os << from_utf8(subst(lang_end_command,
                                        "$$lang",
                                        mainlang))
                        << '\n';
-               texrow.newline();
+               if (using_begin_end)
+                       popLanguageName();
        }
 
        // If the last paragraph is an environment, we'll have to close
        // CJK at the very end to do proper nesting.
-       if (maintext && !is_child && open_encoding_ == CJK) {
-               os << "\\end{CJK}\n";
-               texrow.newline();
-               open_encoding_ = none;
+       if (maintext && !is_child && state->open_encoding_ == CJK) {
+               os << "\\clearpage\n\\end{CJK}\n";
+               state->open_encoding_ = none;
+       }
+       // Likewise for polyglossia or when using begin/end commands
+       // or at the very end of an active branch inset with a language switch
+       Language const * const outer_language = (runparams.local_font != nullptr)
+                       ? runparams.local_font->language() : bparams.language;
+       string const & prev_lang = runparams.use_polyglossia
+                       ? getPolyglossiaEnvName(outer_language)
+                       : outer_language->babel();
+       string const lastpar_lang = runparams.use_polyglossia ?
+               getPolyglossiaEnvName(lastpar_language): lastpar_language->babel();
+       string const & cur_lang = openLanguageName(state);
+       if (((runparams.inbranch && langOpenedAtThisLevel(state) && prev_lang != cur_lang)
+            || (maintext && !is_child)) && !cur_lang.empty()) {
+               os << from_utf8(subst(lang_end_command,
+                                       "$$lang",
+                                       cur_lang))
+                  << '\n';
+               if (using_begin_end)
+                       popLanguageName();
+       } else if (runparams.inbranch && !using_begin_end
+                  && prev_lang != lastpar_lang && !lastpar_lang.empty()) {
+               // with !using_begin_end, cur_lang is empty, so we need to
+               // compare against the paragraph language (and we are in the
+               // last paragraph at this point)
+               os << subst(lang_begin_command, "$$lang", prev_lang) << '\n';
        }
 
        // reset inherited encoding
-       if (cjk_inherited_ > 0) {
-               cjk_inherited_ -= 1;
-               if (cjk_inherited_ == 0)
-                       open_encoding_ = CJK;
+       if (state->cjk_inherited_ > 0) {
+               state->cjk_inherited_ -= 1;
+               if (state->cjk_inherited_ == 0)
+                       state->open_encoding_ = CJK;
        }
-}
 
+       if (multibib_child && mparams.useBibtopic()) {
+               os << "\\end{btUnit}\n";
+               runparams.openbtUnit = false;
+       }
+}
 
+// Switch the input encoding for some part(s) of the document.
 pair<bool, int> switchEncoding(odocstream & os, BufferParams const & bparams,
                   OutputParams const & runparams, Encoding const & newEnc,
-                  bool force)
+                  bool force, bool noswitchmacro)
 {
-       Encoding const & oldEnc = *runparams.encoding;
-       bool moving_arg = runparams.moving_arg;
-       if (!force && ((bparams.inputenc != "auto" && bparams.inputenc != "default")
-               || moving_arg))
+       // Never switch encoding with XeTeX/LuaTeX
+       // or if we're in a moving argument or inherit the outer encoding.
+       if (runparams.isFullUnicode() || newEnc.name() == "inherit")
+               return make_pair(false, 0);     
+
+       // Only switch for auto-selected legacy encodings (inputenc setting
+       // "auto-legacy" or "auto-legacy-plain").
+       // The "listings" environment can force a switch also with other
+       // encoding settings (it does not support variable width encodings
+       // (utf8, jis, ...) under 8-bit latex engines).
+       if (!force && ((bparams.inputenc != "auto-legacy" && bparams.inputenc != "auto-legacy-plain")
+                                  || runparams.moving_arg))
                return make_pair(false, 0);
 
-       // Do nothing if the encoding is unchanged.
-       if (oldEnc.name() == newEnc.name())
+       Encoding const & oldEnc = *runparams.encoding;
+       // Do not switch, if the encoding is unchanged or switching is not supported.
+       if (oldEnc.name() == newEnc.name()
+               || oldEnc.package() == Encoding::japanese
+               || oldEnc.package() == Encoding::none
+               || newEnc.package() == Encoding::none
+               || runparams.for_search)
                return make_pair(false, 0);
-
        // FIXME We ignore encoding switches from/to encodings that do
        // neither support the inputenc package nor the CJK package here.
-       // This does of course only work in special cases (e.g. switch from
-       // tis620-0 to latin1, but the text in latin1 contains ASCII only),
-       // but it is the best we can do
-       if (oldEnc.package() == Encoding::none
-               || newEnc.package() == Encoding::none)
-               return make_pair(false, 0);
+       // This may fail for characters not supported by "unicodesymbols"
+       // or for non-ASCII characters in "listings"
+       // but it is the best we can do.
 
+       // change encoding
        LYXERR(Debug::LATEX, "Changing LaTeX encoding from "
-               << oldEnc.name() << " to " << newEnc.name());
+                  << oldEnc.name() << " to " << newEnc.name());
        os << setEncoding(newEnc.iconvName());
-       if (bparams.inputenc == "default")
-               return make_pair(true, 0);
+       if (bparams.inputenc == "auto-legacy-plain")
+         return make_pair(true, 0);
 
        docstring const inputenc_arg(from_ascii(newEnc.latexName()));
+       OutputState * state = getOutputState();
        switch (newEnc.package()) {
                case Encoding::none:
                case Encoding::japanese:
-                       // shouldn't ever reach here, see above
+                       // shouldn't ever reach here (see above) but avoids warning.
                        return make_pair(true, 0);
                case Encoding::inputenc: {
                        int count = inputenc_arg.length();
                        if (oldEnc.package() == Encoding::CJK &&
-                           open_encoding_ == CJK) {
+                           state->open_encoding_ == CJK) {
                                os << "\\end{CJK}";
-                               open_encoding_ = none;
+                               state->open_encoding_ = none;
                                count += 9;
                        }
                        else if (oldEnc.package() == Encoding::inputenc &&
-                                open_encoding_ == inputenc) {
+                                state->open_encoding_ == inputenc) {
                                os << "\\egroup";
-                               open_encoding_ = none;
+                               state->open_encoding_ = none;
                                count += 7;
                        }
-                       if (runparams.local_font != 0
+                       if (runparams.local_font != nullptr
                            &&  oldEnc.package() == Encoding::CJK) {
                                // within insets, \inputenc switches need
                                // to be embraced within \bgroup...\egroup;
                                // else CJK fails.
                                os << "\\bgroup";
                                count += 7;
-                               open_encoding_ = inputenc;
+                               state->open_encoding_ = inputenc;
                        }
-                       // with the japanese option, inputenc is omitted.
-                       if (runparams.use_japanese)
+                       if (noswitchmacro)
                                return make_pair(true, count);
                        os << "\\inputencoding{" << inputenc_arg << '}';
                        return make_pair(true, count + 16);
@@ -1149,24 +1770,24 @@ pair<bool, int> switchEncoding(odocstream & os, BufferParams const & bparams,
                case Encoding::CJK: {
                        int count = inputenc_arg.length();
                        if (oldEnc.package() == Encoding::CJK &&
-                           open_encoding_ == CJK) {
+                           state->open_encoding_ == CJK) {
                                os << "\\end{CJK}";
                                count += 9;
                        }
                        if (oldEnc.package() == Encoding::inputenc &&
-                           open_encoding_ == inputenc) {
+                           state->open_encoding_ == inputenc) {
                                os << "\\egroup";
                                count += 7;
                        }
-                       os << "\\begin{CJK}{" << inputenc_arg << "}{"
+                       os << "\\begin{CJK}{"
+                          << from_ascii(newEnc.latexName()) << "}{"
                           << from_ascii(bparams.fonts_cjk) << "}";
-                       open_encoding_ = CJK;
+                       state->open_encoding_ = CJK;
                        return make_pair(true, count + 15);
                }
        }
        // Dead code to avoid a warning:
        return make_pair(true, 0);
-
 }
 
 } // namespace lyx