]> git.lyx.org Git - lyx.git/blobdiff - src/support/FileName.cpp
Provide proper fallback if a bibliography processor is not found
[lyx.git] / src / support / FileName.cpp
index 1d114f811489765d89a09189eb190061a13a94ae..482bb93e2135dcdeda0d72721ef30d723d5ed9ef 100644 (file)
 #include "support/FileName.h"
 #include "support/FileNameList.h"
 
-#include "support/convert.h"
 #include "support/debug.h"
 #include "support/filetools.h"
+#include "support/lassert.h"
 #include "support/lstrings.h"
+#include "support/mutex.h"
 #include "support/os.h"
 #include "support/Package.h"
 #include "support/qstring_helpers.h"
 #include <QFileInfo>
 #include <QList>
 #include <QTemporaryFile>
-#include <QTime>
+#include <QElapsedTimer>
 
-#include "support/lassert.h"
-#include <boost/scoped_array.hpp>
+#ifdef _WIN32
+#include <QThread>
+#endif
+
+#include <boost/crc.hpp>
 
+#include <algorithm>
+#include <iterator>
+#include <fstream>
+#include <iomanip>
 #include <map>
 #include <sstream>
-#include <fstream>
-#include <algorithm>
 
 #ifdef HAVE_SYS_TYPES_H
 # include <sys/types.h>
 #include <cerrno>
 #include <fcntl.h>
 
-
-#ifdef HAVE_UNISTD_H
-# include <unistd.h>
-#endif
-
-#if defined(HAVE_MKSTEMP) && ! defined(HAVE_DECL_MKSTEMP)
-extern "C" int mkstemp(char *);
-#endif
-
-#if !defined(HAVE_MKSTEMP) && defined(HAVE_MKTEMP)
-# ifdef HAVE_IO_H
-#  include <io.h>
-# endif
-# ifdef HAVE_PROCESS_H
-#  include <process.h>
-# endif
-#endif
+// Three implementations of checksum(), depending on having mmap support or not.
+#if defined(HAVE_MMAP) && defined(HAVE_MUNMAP)
+#define SUM_WITH_MMAP
+#include <sys/mman.h>
+#endif // SUM_WITH_MMAP
 
 using namespace std;
+using namespace lyx::support;
 
 namespace lyx {
 namespace support {
 
-
 /////////////////////////////////////////////////////////////////////
 //
 // FileName::Private
@@ -90,23 +84,34 @@ struct FileName::Private
 {
        Private() {}
 
-       Private(string const & abs_filename) : fi(toqstr(abs_filename))
+       Private(string const & abs_filename) : fi(toqstr(handleTildeName(abs_filename)))
        {
+               name = fromqstr(fi.absoluteFilePath());
                fi.setCaching(fi.exists() ? true : false);
        }
        ///
-       inline void refresh() 
+       inline void refresh()
        {
-// There seems to be a bug in Qt >= 4.2.0, at least, that causes problems with
-// QFileInfo::refresh() on *nix. So we recreate the object in that case.
-// FIXME: When Trolltech fixes the bug, we will have to replace 0x999999 below
-// with the actual working minimum version.
-#if defined(_WIN32) || (QT_VERSION >= 0x999999)
                fi.refresh();
-#else
-               fi = QFileInfo(fi.absoluteFilePath());
-#endif
        }
+
+       static
+       bool isFilesystemEqual(QString const & lhs, QString const & rhs)
+       {
+               return QString::compare(lhs, rhs, os::isFilesystemCaseSensitive() ?
+                       Qt::CaseSensitive : Qt::CaseInsensitive) == 0;
+       }
+
+       static
+       string const handleTildeName(string const & name)
+       {
+               return name == "~" ? Package::get_home_dir().absFileName() :
+                       prefixIs(name, "~/") ? Package::get_home_dir().absFileName() + name.substr(1) :
+                       name;
+       }
+
+       /// The absolute file name in UTF-8 encoding.
+       std::string name;
        ///
        QFileInfo fi;
 };
@@ -126,6 +131,8 @@ FileName::FileName() : d(new Private)
 FileName::FileName(string const & abs_filename)
        : d(abs_filename.empty() ? new Private : new Private(abs_filename))
 {
+       //LYXERR(Debug::FILES, "FileName(" << abs_filename << ')');
+       LATTEST(empty() || isAbsolute(d->name));
 }
 
 
@@ -137,12 +144,22 @@ FileName::~FileName()
 
 FileName::FileName(FileName const & rhs) : d(new Private)
 {
+       d->name = rhs.d->name;
        d->fi = rhs.d->fi;
 }
 
 
+FileName::FileName(FileName const & rhs, string const & suffix) : d(new Private)
+{
+       set(rhs, suffix);
+}
+
+
 FileName & FileName::operator=(FileName const & rhs)
 {
+       if (&rhs == this)
+               return *this;
+       d->name = rhs.d->name;
        d->fi = rhs.d->fi;
        return *this;
 }
@@ -150,37 +167,77 @@ FileName & FileName::operator=(FileName const & rhs)
 
 bool FileName::empty() const
 {
-       return d->fi.absoluteFilePath().isEmpty();
+       return d->name.empty();
 }
 
 
-bool FileName::isAbsolute() const
+bool FileName::isAbsolute(string const & name)
 {
-       return d->fi.isAbsolute();
+       QFileInfo fi(toqstr(Private::handleTildeName(name)));
+       return fi.isAbsolute();
 }
 
 
-string FileName::absFilename() const
+string FileName::absFileName() const
 {
-       return fromqstr(d->fi.absoluteFilePath());
+       return d->name;
+}
+
+
+string FileName::realPath() const
+{
+       return os::real_path(absFileName());
 }
 
 
 void FileName::set(string const & name)
 {
-       d->fi.setFile(toqstr(name));
+       d->fi.setFile(toqstr(Private::handleTildeName(name)));
+       d->name = fromqstr(d->fi.absoluteFilePath());
+       //LYXERR(Debug::FILES, "FileName::set(" << name << ')');
+       LATTEST(empty() || isAbsolute(d->name));
+}
+
+
+void FileName::set(FileName const & rhs, string const & suffix)
+{
+       if (!rhs.d->fi.isDir())
+               d->fi.setFile(rhs.d->fi.filePath() + toqstr(suffix));
+       else
+               d->fi.setFile(QDir(rhs.d->fi.absoluteFilePath()), toqstr(suffix));
+       d->name = fromqstr(d->fi.absoluteFilePath());
+       //LYXERR(Debug::FILES, "FileName::set(" << d->name << ')');
+       LATTEST(empty() || isAbsolute(d->name));
 }
 
 
 void FileName::erase()
 {
+       d->name.clear();
        d->fi = QFileInfo();
 }
 
 
-bool FileName::copyTo(FileName const & name) const
+bool FileName::copyTo(FileName const & name, bool keepsymlink) const
+{
+       FileNameSet visited;
+       return copyTo(name, keepsymlink, visited);
+}
+
+
+bool FileName::copyTo(FileName const & name, bool keepsymlink,
+                      FileName::FileNameSet & visited) const
 {
-       LYXERR(Debug::FILES, "Copying " << name);
+       LYXERR(Debug::FILES, "Copying " << name << " keep symlink: " << keepsymlink);
+       if (keepsymlink && name.isSymLink()) {
+               visited.insert(*this);
+               FileName const target(fromqstr(name.d->fi.symLinkTarget()));
+               if (visited.find(target) != visited.end()) {
+                       LYXERR(Debug::FILES, "Found circular symlink: " << target);
+                       return false;
+               }
+               return copyTo(target, true);
+       }
        QFile::remove(name.d->fi.absoluteFilePath());
        bool success = QFile::copy(d->fi.absoluteFilePath(), name.d->fi.absoluteFilePath());
        if (!success)
@@ -192,7 +249,9 @@ bool FileName::copyTo(FileName const & name) const
 
 bool FileName::renameTo(FileName const & name) const
 {
+       LYXERR(Debug::FILES, "Renaming " << name << " as " << *this);
        bool success = QFile::rename(d->fi.absoluteFilePath(), name.d->fi.absoluteFilePath());
+       d->refresh();
        if (!success)
                LYXERR0("Could not rename file " << *this << " to " << name);
        return success;
@@ -201,10 +260,26 @@ bool FileName::renameTo(FileName const & name) const
 
 bool FileName::moveTo(FileName const & name) const
 {
+       LYXERR(Debug::FILES, "Moving " << *this << " to " << name);
+#ifdef _WIN32
+       // there's a locking problem on Windows sometimes, so
+       // we will keep trying for five seconds, in the hope
+       // that clears.
+       name.refresh();
+       if (name.exists()) {
+               bool removed = name.removeFile();
+               int tries = 1;
+               while (!removed && tries < 6)   {
+                       QThread::sleep(1);
+                       removed = name.removeFile();
+                       tries++;
+               }
+       }
+#else
        QFile::remove(name.d->fi.absoluteFilePath());
+#endif
 
-       bool success = QFile::rename(d->fi.absoluteFilePath(),
-               name.d->fi.absoluteFilePath());
+       bool const success = renameTo(name);
        if (!success)
                LYXERR0("Could not move file " << *this << " to " << name);
        return success;
@@ -223,14 +298,32 @@ bool FileName::changePermission(unsigned long int mode) const
        return true;
 }
 
+bool FileName::clonePermissions(FileName const & source)
+{
+       QFile fin(toqstr(source.absFileName()));
+       QFile f(toqstr(absFileName()));
+
+       return f.setPermissions(fin.permissions());
+}
 
 string FileName::toFilesystemEncoding() const
 {
+       // This doesn't work on Windows for non ascii file names.
        QByteArray const encoded = QFile::encodeName(d->fi.absoluteFilePath());
        return string(encoded.begin(), encoded.end());
 }
 
 
+string FileName::toSafeFilesystemEncoding(os::file_access how) const
+{
+       // This will work on Windows for non ascii file names.
+       QString const safe_path =
+               toqstr(os::safe_internal_path(absFileName(), how));
+       QByteArray const encoded = QFile::encodeName(safe_path);
+       return string(encoded.begin(), encoded.end());
+}
+
+
 FileName FileName::fromFilesystemEncoding(string const & name)
 {
        QByteArray const encoded(name.c_str(), name.length());
@@ -240,37 +333,42 @@ FileName FileName::fromFilesystemEncoding(string const & name)
 
 bool FileName::exists() const
 {
-       return d->fi.exists();
+       return !empty() && d->fi.exists();
 }
 
 
 bool FileName::isSymLink() const
 {
-       return d->fi.isSymLink();
+       return !empty() && d->fi.isSymLink();
 }
 
 
+//QFileInfo caching info might fool this test if file was changed meanwhile.
+//refresh() helps, but we don't want to put it blindly here, because it might
+//trigger slowdown on networked file systems.
 bool FileName::isFileEmpty() const
 {
+       LASSERT(!empty(), return true);
        return d->fi.size() == 0;
 }
 
 
 bool FileName::isDirectory() const
 {
-       return d->fi.isDir();
+       return !empty() && d->fi.isDir();
 }
 
 
 bool FileName::isReadOnly() const
 {
+       LASSERT(!empty(), return true);
        return d->fi.isReadable() && !d->fi.isWritable();
 }
 
 
 bool FileName::isReadableDirectory() const
 {
-       return d->fi.isDir() && d->fi.isReadable();
+       return isDirectory() && d->fi.isReadable();
 }
 
 
@@ -282,35 +380,69 @@ string FileName::onlyFileName() const
 
 string FileName::onlyFileNameWithoutExt() const
 {
-       return fromqstr(d->fi.baseName());
+       return fromqstr(d->fi.completeBaseName());
+}
+
+
+string FileName::extension() const
+{
+       return fromqstr(d->fi.suffix());
+}
+
+
+bool FileName::hasExtension(const string & ext)
+{
+       return Private::isFilesystemEqual(d->fi.suffix(), toqstr(ext));
 }
 
 
 FileName FileName::onlyPath() const
 {
        FileName path;
+       if (empty())
+               return path;
+       path.d->fi.setFile(d->fi.path());
+       path.d->name = fromqstr(path.d->fi.absoluteFilePath());
+       return path;
+}
+
+
+FileName FileName::parentPath() const
+{
+       FileName path;
+       // return empty path for parent of root dir
+       // parent of empty path is empty too
+       if (empty() || d->fi.isRoot())
+               return path;
        path.d->fi.setFile(d->fi.path());
+       path.d->name = fromqstr(path.d->fi.absoluteFilePath());
        return path;
 }
 
 
 bool FileName::isReadableFile() const
 {
-       return d->fi.isFile() && d->fi.isReadable();
+       return !empty() && d->fi.isFile() && d->fi.isReadable();
 }
 
 
 bool FileName::isWritable() const
 {
-       return d->fi.isWritable();
+       return !empty() && d->fi.isWritable();
 }
 
 
 bool FileName::isDirWritable() const
 {
-       LYXERR(Debug::FILES, "isDirWriteable: " << *this);
-       FileName const tmpfl = FileName::tempName(absFilename() + "lyxwritetest");
-       return !tmpfl.empty();
+       LASSERT(isDirectory(), return false);
+       QFileInfo tmp(QDir(d->fi.absoluteFilePath()), "lyxwritetest");
+       QTemporaryFile qt_tmp(tmp.absoluteFilePath());
+       if (qt_tmp.open()) {
+               LYXERR(Debug::FILES, "Directory " << *this << " is writable");
+               return true;
+       }
+       LYXERR(Debug::FILES, "Directory " << *this << " is not writable");
+       return false;
 }
 
 
@@ -322,7 +454,9 @@ FileNameList FileName::dirList(string const & ext) const
                return dirlist;
        }
 
-       QDir dir = d->fi.absoluteDir();
+       // If the directory is specified without a trailing '/', absoluteDir()
+       // would return the parent dir, so we must use absoluteFilePath() here.
+       QDir dir = d->fi.absoluteFilePath();
 
        if (!ext.empty()) {
                QString filter;
@@ -347,35 +481,23 @@ FileNameList FileName::dirList(string const & ext) const
 }
 
 
-FileName FileName::tempName(string const & mask)
+FileName FileName::getcwd()
 {
-       FileName tmp_name(mask);
-       string tmpfl;
-       if (tmp_name.d->fi.isAbsolute())
-               tmpfl = mask;
-       else
-               tmpfl = package().temp_dir().absFilename() + "/" + mask;
-
-       QTemporaryFile qt_tmp(toqstr(tmpfl));
-       if (qt_tmp.open()) {
-               tmp_name.d->fi.setFile(qt_tmp.fileName());
-               LYXERR(Debug::FILES, "Temporary file `" << tmp_name << "' created.");
-               return tmp_name;
-       }
-       LYXERR(Debug::FILES, "LyX Error: Unable to create temporary file.");
-       return FileName();
+       // return makeAbsPath("."); would create an infinite loop
+       QFileInfo fi(".");
+       return FileName(fromqstr(fi.absoluteFilePath()));
 }
 
 
-FileName FileName::getcwd()
+FileName FileName::tempPath()
 {
-       return FileName(".");
+       return FileName(os::internal_path(fromqstr(QDir::tempPath())));
 }
 
 
-FileName FileName::tempPath()
+void FileName::refresh() const
 {
-       return FileName(fromqstr(QDir::tempPath()));
+       d->refresh();
 }
 
 
@@ -385,7 +507,11 @@ time_t FileName::lastModified() const
        // been touched between the object creation and now, we refresh the file
        // information.
        d->refresh();
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 8, 0))
+       return d->fi.lastModified().toSecsSinceEpoch();
+#else
        return d->fi.lastModified().toTime_t();
+#endif
 }
 
 
@@ -395,34 +521,118 @@ bool FileName::chdir() const
 }
 
 
-extern unsigned long sum(char const * file);
+bool FileName::link(FileName const & name) const
+{
+       return QFile::link(toqstr(absFileName()), toqstr(name.absFileName()));
+}
+
+
+unsigned long checksum_ifstream_fallback(char const * file)
+{
+       unsigned long result = 0;
+       //LYXERR(Debug::FILES, "lyx::sum() using istreambuf_iterator (fast)");
+       ifstream ifs(file, ios_base::in | ios_base::binary);
+       if (!ifs)
+               return result;
+
+       istreambuf_iterator<char> beg(ifs);
+       istreambuf_iterator<char> end;
+       boost::crc_32_type crc;
+       crc = for_each(beg, end, crc);
+       result = crc.checksum();
+       return result;
+}
 
 unsigned long FileName::checksum() const
 {
+       unsigned long result = 0;
+
        if (!exists()) {
-               //LYXERR0("File \"" << absFilename() << "\" does not exist!");
-               return 0;
+               //LYXERR0("File \"" << absFileName() << "\" does not exist!");
+               return result;
        }
        // a directory may be passed here so we need to test it. (bug 3622)
        if (isDirectory()) {
-               LYXERR0('"' << absFilename() << "\" is a directory!");
-               return 0;
+               LYXERR0('"' << absFileName() << "\" is a directory!");
+               return result;
+       }
+
+       // This is used in the debug output at the end of the method.
+       static QElapsedTimer t;
+       if (lyxerr.debugging(Debug::FILES))
+               t.restart();
+
+#if QT_VERSION >= 0x999999
+       // First version of checksum uses Qt4.4 mmap support.
+       // FIXME: This code is not ready with Qt4.4.2,
+       // see http://www.lyx.org/trac/ticket/5293
+       // FIXME: should we check if the MapExtension extension is supported?
+       // see QAbstractFileEngine::supportsExtension() and
+       // QAbstractFileEngine::MapExtension)
+       QFile qf(fi.filePath());
+       if (!qf.open(QIODevice::ReadOnly))
+               return result;
+       qint64 size = fi.size();
+       uchar * ubeg = qf.map(0, size);
+       uchar * uend = ubeg + size;
+       boost::crc_32_type ucrc;
+       ucrc.process_block(ubeg, uend);
+       qf.unmap(ubeg);
+       qf.close();
+       result = ucrc.checksum();
+
+#else // QT_VERSION
+
+       string const encoded = toSafeFilesystemEncoding();
+       char const * file = encoded.c_str();
+
+ #ifdef SUM_WITH_MMAP
+       //LYXERR(Debug::FILES, "using mmap (lightning fast)");
+
+       int fd = open(file, O_RDONLY);
+       if (!fd)
+               return result;
+
+       struct stat info;
+       if (fstat(fd, &info)){
+               // fstat fails on samba shares (bug 5891)
+               close(fd);
+               return checksum_ifstream_fallback(file);
+       }
+
+       void * mm = mmap(0, info.st_size, PROT_READ,
+                        MAP_PRIVATE, fd, 0);
+       // Some platforms have the wrong type for MAP_FAILED (compaq cxx).
+       if (mm == reinterpret_cast<void*>(MAP_FAILED)) {
+               close(fd);
+               return result;
        }
-       if (!lyxerr.debugging(Debug::FILES))
-               return sum(absFilename().c_str());
 
-       QTime t;
-       t.start();
-       unsigned long r = sum(absFilename().c_str());
-       lyxerr << "Checksumming \"" << absFilename() << "\" lasted "
-               << t.elapsed() << " ms." << endl;
-       return r;
+       char * beg = static_cast<char*>(mm);
+       char * end = beg + info.st_size;
+
+       boost::crc_32_type crc;
+       crc.process_block(beg, end);
+       result = crc.checksum();
+
+       munmap(mm, info.st_size);
+       close(fd);
+
+ #else // no SUM_WITH_MMAP
+       result = checksum_ifstream_fallback(file);
+ #endif // SUM_WITH_MMAP
+#endif // QT_VERSION
+
+       LYXERR(Debug::FILES, "Checksumming \"" << absFileName() << "\" "
+               << result << " lasted " << QString::number(t.elapsed()) << " ms.");
+       return result;
 }
 
 
 bool FileName::removeFile() const
 {
        bool const success = QFile::remove(d->fi.absoluteFilePath());
+       d->refresh();
        if (!success && exists())
                LYXERR0("Could not delete file " << *this);
        return success;
@@ -441,12 +651,12 @@ static bool rmdir(QFileInfo const & fi)
                        continue;
                bool removed;
                if (list.at(i).isDir()) {
-                       LYXERR(Debug::FILES, "Removing dir " 
+                       LYXERR(Debug::FILES, "Removing dir "
                                << fromqstr(list.at(i).absoluteFilePath()));
                        removed = rmdir(list.at(i));
                }
                else {
-                       LYXERR(Debug::FILES, "Removing file " 
+                       LYXERR(Debug::FILES, "Removing file "
                                << fromqstr(list.at(i).absoluteFilePath()));
                        removed = dir.remove(list.at(i).fileName());
                }
@@ -455,7 +665,7 @@ static bool rmdir(QFileInfo const & fi)
                        LYXERR0("Could not delete "
                                << fromqstr(list.at(i).absoluteFilePath()));
                }
-       } 
+       }
        QDir parent = fi.absolutePath();
        success &= parent.rmdir(fi.fileName());
        return success;
@@ -472,6 +682,7 @@ bool FileName::destroyDirectory() const
 }
 
 
+// Only used in non Win32 platforms
 static int mymkdir(char const * pathname, unsigned long int mode)
 {
        // FIXME: why don't we have mode_t in lyx::mkdir prototype ??
@@ -500,16 +711,22 @@ static int mymkdir(char const * pathname, unsigned long int mode)
 
 bool FileName::createDirectory(int permission) const
 {
-       LASSERT(!empty(), /**/);
+       LASSERT(!empty(), return false);
+#ifdef Q_OS_WIN32
+       // FIXME: "Permissions of created directories are ignored on this system."
+       return createPath();
+#else
        return mymkdir(toFilesystemEncoding().c_str(), permission) == 0;
+#endif
 }
 
 
 bool FileName::createPath() const
 {
-       LASSERT(!empty(), /**/);
+       LASSERT(!empty(), return false);
+       LYXERR(Debug::FILES, "creating path '" << *this << "'.");
        if (isDirectory())
-               return true;
+               return false;
 
        QDir dir;
        bool success = dir.mkpath(d->fi.absoluteFilePath());
@@ -527,14 +744,14 @@ docstring const FileName::absoluteFilePath() const
 
 docstring FileName::displayName(int threshold) const
 {
-       return makeDisplayPath(absFilename(), threshold);
+       return makeDisplayPath(absFileName(), threshold);
 }
 
 
 docstring FileName::fileContents(string const & encoding) const
 {
        if (!isReadableFile()) {
-               LYXERR0("File '" << *this << "' is not redable!");
+               LYXERR0("File '" << *this << "' is not readable!");
                return docstring();
        }
 
@@ -557,7 +774,11 @@ docstring FileName::fileContents(string const & encoding) const
        if (encoding.empty() || encoding == "UTF-8")
                s = QString::fromUtf8(contents.data());
        else if (encoding == "ascii")
+#if (QT_VERSION < 0x050000)
                s = QString::fromAscii(contents.data());
+#else
+               s = QString::fromLatin1(contents.data());
+#endif
        else if (encoding == "local8bit")
                s = QString::fromLocal8Bit(contents.data());
        else if (encoding == "latin1")
@@ -570,7 +791,7 @@ docstring FileName::fileContents(string const & encoding) const
 void FileName::changeExtension(string const & extension)
 {
        // FIXME: use Qt native methods...
-       string const oldname = absFilename();
+       string const oldname = absFileName();
        string::size_type const last_slash = oldname.rfind('/');
        string::size_type last_dot = oldname.rfind('.');
        if (last_dot < last_slash && last_slash != string::npos)
@@ -587,222 +808,89 @@ void FileName::changeExtension(string const & extension)
 }
 
 
-string FileName::guessFormatFromContents() const
-{
-       // the different filetypes and what they contain in one of the first lines
-       // (dots are any characters).           (Herbert 20020131)
-       // AGR  Grace...
-       // BMP  BM...
-       // EPS  %!PS-Adobe-3.0 EPSF...
-       // FIG  #FIG...
-       // FITS ...BITPIX...
-       // GIF  GIF...
-       // JPG  JFIF
-       // PDF  %PDF-...
-       // PNG  .PNG...
-       // PBM  P1... or P4     (B/W)
-       // PGM  P2... or P5     (Grayscale)
-       // PPM  P3... or P6     (color)
-       // PS   %!PS-Adobe-2.0 or 1.0,  no "EPSF"!
-       // SGI  \001\332...     (decimal 474)
-       // TGIF %TGIF...
-       // TIFF II... or MM...
-       // XBM  ..._bits[]...
-       // XPM  /* XPM */    sometimes missing (f.ex. tgif-export)
-       //      ...static char *...
-       // XWD  \000\000\000\151        (0x00006900) decimal 105
-       //
-       // GZIP \037\213        http://www.ietf.org/rfc/rfc1952.txt
-       // ZIP  PK...                   http://www.halyava.ru/document/ind_arch.htm
-       // Z    \037\235                UNIX compress
-
-       // paranoia check
-       if (empty() || !isReadableFile())
-               return string();
-
-       ifstream ifs(toFilesystemEncoding().c_str());
-       if (!ifs)
-               // Couldn't open file...
-               return string();
-
-       // gnuzip
-       static string const gzipStamp = "\037\213";
-
-       // PKZIP
-       static string const zipStamp = "PK";
-
-       // compress
-       static string const compressStamp = "\037\235";
-
-       // Maximum strings to read
-       int const max_count = 50;
-       int count = 0;
-
-       string str;
-       string format;
-       bool firstLine = true;
-       while ((count++ < max_count) && format.empty()) {
-               if (ifs.eof()) {
-                       LYXERR(Debug::GRAPHICS, "filetools(getFormatFromContents)\n"
-                               << "\tFile type not recognised before EOF!");
-                       break;
-               }
-
-               getline(ifs, str);
-               string const stamp = str.substr(0, 2);
-               if (firstLine && str.size() >= 2) {
-                       // at first we check for a zipped file, because this
-                       // information is saved in the first bytes of the file!
-                       // also some graphic formats which save the information
-                       // in the first line, too.
-                       if (prefixIs(str, gzipStamp)) {
-                               format =  "gzip";
-
-                       } else if (stamp == zipStamp) {
-                               format =  "zip";
-
-                       } else if (stamp == compressStamp) {
-                               format =  "compress";
-
-                       // the graphics part
-                       } else if (stamp == "BM") {
-                               format =  "bmp";
-
-                       } else if (stamp == "\001\332") {
-                               format =  "sgi";
-
-                       // PBM family
-                       // Don't need to use str.at(0), str.at(1) because
-                       // we already know that str.size() >= 2
-                       } else if (str[0] == 'P') {
-                               switch (str[1]) {
-                               case '1':
-                               case '4':
-                                       format =  "pbm";
-                                   break;
-                               case '2':
-                               case '5':
-                                       format =  "pgm";
-                                   break;
-                               case '3':
-                               case '6':
-                                       format =  "ppm";
-                               }
-                               break;
-
-                       } else if ((stamp == "II") || (stamp == "MM")) {
-                               format =  "tiff";
-
-                       } else if (prefixIs(str,"%TGIF")) {
-                               format =  "tgif";
-
-                       } else if (prefixIs(str,"#FIG")) {
-                               format =  "fig";
-
-                       } else if (prefixIs(str,"GIF")) {
-                               format =  "gif";
-
-                       } else if (str.size() > 3) {
-                               int const c = ((str[0] << 24) & (str[1] << 16) &
-                                              (str[2] << 8)  & str[3]);
-                               if (c == 105) {
-                                       format =  "xwd";
-                               }
-                       }
-
-                       firstLine = false;
-               }
-
-               if (!format.empty())
-                   break;
-               else if (contains(str,"EPSF"))
-                       // dummy, if we have wrong file description like
-                       // %!PS-Adobe-2.0EPSF"
-                       format = "eps";
-
-               else if (contains(str, "Grace"))
-                       format = "agr";
-
-               else if (contains(str, "JFIF"))
-                       format = "jpg";
-
-               else if (contains(str, "%PDF"))
-                       format = "pdf";
-
-               else if (contains(str, "PNG"))
-                       format = "png";
-
-               else if (contains(str, "%!PS-Adobe")) {
-                       // eps or ps
-                       ifs >> str;
-                       if (contains(str,"EPSF"))
-                               format = "eps";
-                       else
-                           format = "ps";
-               }
-
-               else if (contains(str, "_bits[]"))
-                       format = "xbm";
-
-               else if (contains(str, "XPM") || contains(str, "static char *"))
-                       format = "xpm";
-
-               else if (contains(str, "BITPIX"))
-                       format = "fits";
-       }
-
-       if (!format.empty()) {
-               LYXERR(Debug::GRAPHICS, "Recognised Fileformat: " << format);
-               return format;
-       }
-
-       LYXERR(Debug::GRAPHICS, "filetools(getFormatFromContents)\n"
-               << "\tCouldn't find a known format!");
-       return string();
+docstring const FileName::relPath(string const & path) const
+{
+       // FIXME UNICODE
+       return makeRelPath(absoluteFilePath(), from_utf8(path));
 }
 
 
-bool FileName::isZippedFile() const
+// Note: According to Qt, QFileInfo::operator== is undefined when
+// both files do not exist (Qt4.5 gives true for all non-existent
+// files, while Qt4.4 compares the filenames).
+// see:
+// http://www.qtsoftware.com/developer/task-tracker/
+//   index_html?id=248471&method=entry.
+bool equivalent(FileName const & l, FileName const & r)
 {
-       string const type = guessFormatFromContents();
-       return contains("gzip zip compress", type) && !type.empty();
-}
+       // FIXME: In future use Qt.
+       // Qt 4.4: We need to solve this warning from Qt documentation:
+       // * Long and short file names that refer to the same file on Windows are
+       //   treated as if they referred to different files.
+       // This is supposed to be fixed for Qt5.
+       FileName const lhs(os::internal_path(l.absFileName()));
+       FileName const rhs(os::internal_path(r.absFileName()));
+
+       if (lhs.empty())
+               // QFileInfo::operator==() returns false if the two QFileInfo are empty.
+               return rhs.empty();
+
+       if (rhs.empty())
+               // Avoid unnecessary checks below.
+               return false;
 
+       lhs.d->refresh();
+       rhs.d->refresh();
 
-docstring const FileName::relPath(string const & path) const
-{
-       // FIXME UNICODE
-       return makeRelPath(absoluteFilePath(), from_utf8(path));
+       if (!lhs.d->fi.isSymLink() && !rhs.d->fi.isSymLink()) {
+               // Qt already checks if the filesystem is case sensitive or not.
+               // see note above why the extra check with fileName is needed.
+               return lhs.d->fi == rhs.d->fi
+                       && lhs.d->fi.fileName() == rhs.d->fi.fileName();
+       }
+
+       // FIXME: When/if QFileInfo support symlink comparison, remove this code.
+       QFileInfo fi1(lhs.d->fi);
+       if (fi1.isSymLink())
+               fi1 = QFileInfo(fi1.symLinkTarget());
+       QFileInfo fi2(rhs.d->fi);
+       if (fi2.isSymLink())
+               fi2 = QFileInfo(fi2.symLinkTarget());
+       // see note above why the extra check with fileName is needed.
+       return fi1 == fi2 && fi1.fileName() == fi2.fileName();
 }
 
 
 bool operator==(FileName const & lhs, FileName const & rhs)
 {
-       return lhs.absFilename() == rhs.absFilename();
+       return os::isFilesystemCaseSensitive()
+               ? lhs.absFileName() == rhs.absFileName()
+               : !QString::compare(toqstr(lhs.absFileName()),
+                               toqstr(rhs.absFileName()), Qt::CaseInsensitive);
 }
 
 
 bool operator!=(FileName const & lhs, FileName const & rhs)
 {
-       return lhs.absFilename() != rhs.absFilename();
+       return !(operator==(lhs, rhs));
 }
 
 
 bool operator<(FileName const & lhs, FileName const & rhs)
 {
-       return lhs.absFilename() < rhs.absFilename();
+       return lhs.absFileName() < rhs.absFileName();
 }
 
 
 bool operator>(FileName const & lhs, FileName const & rhs)
 {
-       return lhs.absFilename() > rhs.absFilename();
+       return lhs.absFileName() > rhs.absFileName();
 }
 
 
 ostream & operator<<(ostream & os, FileName const & filename)
 {
-       return os << filename.absFilename();
+       return os << filename.absFileName();
 }
 
 
@@ -819,57 +907,60 @@ DocFileName::DocFileName()
 
 
 DocFileName::DocFileName(string const & abs_filename, bool save_abs)
-       : FileName(abs_filename), save_abs_path_(save_abs), zipped_valid_(false)
+       : FileName(abs_filename), save_abs_path_(save_abs)
 {}
 
 
 DocFileName::DocFileName(FileName const & abs_filename, bool save_abs)
-       : FileName(abs_filename), save_abs_path_(save_abs), zipped_valid_(false)
+       : FileName(abs_filename), save_abs_path_(save_abs)
 {}
 
 
 void DocFileName::set(string const & name, string const & buffer_path)
 {
-       FileName::set(name);
-       bool const nameIsAbsolute = isAbsolute();
-       save_abs_path_ = nameIsAbsolute;
-       if (!nameIsAbsolute)
-               FileName::set(makeAbsPath(name, buffer_path).absFilename());
-       zipped_valid_ = false;
+       save_abs_path_ = isAbsolute(name);
+       if (save_abs_path_)
+               FileName::set(name);
+       else
+               FileName::set(makeAbsPath(name, buffer_path).absFileName());
 }
 
 
 void DocFileName::erase()
 {
        FileName::erase();
-       zipped_valid_ = false;
 }
 
 
-string DocFileName::relFilename(string const & path) const
+string DocFileName::relFileName(string const & path) const
 {
        // FIXME UNICODE
        return to_utf8(relPath(path));
 }
 
 
-string DocFileName::outputFilename(string const & path) const
+string DocFileName::outputFileName(string const & path) const
 {
-       return save_abs_path_ ? absFilename() : relFilename(path);
+       return save_abs_path_ ? absFileName() : relFileName(path);
 }
 
 
-string DocFileName::mangledFilename(string const & dir) const
+string DocFileName::mangledFileName(string const & dir) const
 {
+       // Concurrent access to these variables is possible.
+
        // We need to make sure that every DocFileName instance for a given
        // filename returns the same mangled name.
        typedef map<string, string> MangledMap;
        static MangledMap mangledNames;
-       MangledMap::const_iterator const it = mangledNames.find(absFilename());
+       static Mutex mangledMutex;
+       // this locks both access to mangledNames and counter below
+       Mutex::Locker lock(&mangledMutex);
+       MangledMap::const_iterator const it = mangledNames.find(absFileName());
        if (it != mangledNames.end())
                return (*it).second;
 
-       string const name = absFilename();
+       string const name = absFileName();
        // Now the real work
        string mname = os::internal_path(name);
        // Remove the extension.
@@ -883,7 +974,7 @@ string DocFileName::mangledFilename(string const & dir) const
        // in the name.
        static string const keep = "abcdefghijklmnopqrstuvwxyz"
                                   "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-                                  "+,-0123456789;=";
+                                  "+-0123456789;=";
        string::size_type pos = 0;
        while ((pos = mname.find_first_not_of(keep, pos)) != string::npos)
                mname[pos++] = '_';
@@ -916,30 +1007,21 @@ string DocFileName::mangledFilename(string const & dir) const
                }
        }
 
-       mangledNames[absFilename()] = mname;
+       mangledNames[absFileName()] = mname;
        return mname;
 }
 
 
-bool DocFileName::isZipped() const
-{
-       if (!zipped_valid_) {
-               zipped_ = isZippedFile();
-               zipped_valid_ = true;
-       }
-       return zipped_;
-}
-
-
-string DocFileName::unzippedFilename() const
+string DocFileName::unzippedFileName() const
 {
-       return unzippedFileName(absFilename());
+       return support::unzippedFileName(absFileName());
 }
 
 
 bool operator==(DocFileName const & lhs, DocFileName const & rhs)
 {
-       return lhs.absFilename() == rhs.absFilename()
+       return static_cast<FileName const &>(lhs)
+               == static_cast<FileName const &>(rhs)
                && lhs.saveAbsPath() == rhs.saveAbsPath();
 }