[LyX/master] If we successfully save a file but fail to move it to its proper location, then, if we made a backup and the original file was not a symlink, we moved that file, so it will look to the user as if it was deleted. This is bug

[Richard Heck]

commit 8ec3e3283a7384215afede4b6177852d338d708a
Author: Richard Heck <rgh...@lyx.org>
Date:   Fri Aug 8 12:02:20 2014 -0400

    If we successfully save a file but fail to move it to its proper location,
    then, if we made a backup and the original file was not a symlink, we moved
    that file, so it will look to the user as if it was deleted. This is bug

diff --git a/src/Buffer.cpp b/src/Buffer.cpp
index bfd1676..9dd2a25 100644
--- a/src/Buffer.cpp
+++ b/src/Buffer.cpp
@@ -1301,17 +1301,20 @@ bool Buffer::save() const
        // proper location once that has been done successfully. that
        // way we preserve the original file if something goes wrong.
        TempFile tempfile(fileName().onlyPath(), "tmpXXXXXX.lyx");
-       FileName savefile(tempfile.name());
+       bool const symlink = fileName().isSymLink();
+       if (!symlink)
+               tempfile.setAutoRemove(false);
 
+       FileName savefile(tempfile.name());
        LYXERR(Debug::FILES, "Saving to " << savefile.absFileName());
        if (!writeFile(savefile))
                return false;
 
        // we will set this to false if we fail
        bool made_backup = true;
-       bool const symlink = fileName().isSymLink();
+
+       FileName backupName(absFileName() + '~');
        if (lyxrc.make_backup) {
-               FileName backupName(absFileName() + '~');
                if (!lyxrc.backupdir_path.empty()) {
                        string const mangledName =
                                subst(subst(backupName.absFileName(), '/', 
'!'), ':', '!');
@@ -1338,22 +1341,39 @@ bool Buffer::save() const
 
        // If we have no symlink, we can simply rename the temp file.
        // Otherwise, we need to copy it so the symlink stays intact.
-       if (!symlink)
-               tempfile.setAutoRemove(false);
-       if (made_backup &&
-           (symlink ? savefile.copyTo(fileName(), true) : 
savefile.moveTo(fileName()))) {
+       if (made_backup && symlink ? savefile.copyTo(fileName(), true) :
+                                          savefile.moveTo(fileName()))
+       {
                // saveCheckSum() was already called by writeFile(), but the
                // time stamp is invalidated by copying/moving
                saveCheckSum();
                markClean();
                return true;
        }
-       // else
-       Alert::error(_("Write failure"),
-                    bformat(_("Cannot move saved file to:\n  %1$s.\n"
-                              "But the file has successfully been saved as:\n  
%2$s."),
-                            from_utf8(fileName().absFileName()),
-                from_utf8(savefile.absFileName())));
+       // else we saved the file, but failed to move it to the right location.
+
+       if (lyxrc.make_backup && made_backup && !symlink) {
+               // the original file was moved to filename.lyx~, so it will look
+               // to the user as if it was deleted. (see bug #9234.) we could 
try
+               // to restore it, but that would basically mean trying to do 
again
+               // what we just failed to do. better to leave things as they 
are.
+               Alert::error(_("Write failure"),
+                            bformat(_("The file has successfully been saved 
as:\n  %1$s.\n"
+                          "But LyX could not move it to:\n  %2$s.\n"
+                                                        "Your original file 
has been backed up to:\n  %3$s"),
+                                    from_utf8(savefile.absFileName()),
+             from_utf8(fileName().absFileName()),
+                        from_utf8(backupName.absFileName())));
+       } else {
+               // either we did not try to make a backup, or else we tried and 
failed,
+               // or else the original file was a symlink, in which case it 
was copied,
+               // not moved. so the original file is intact.
+               Alert::error(_("Write failure"),
+                            bformat(_("Cannot move saved file to:\n  %1$s.\n"
+                                      "But the file has successfully been 
saved as:\n  %2$s."),
+                                    from_utf8(fileName().absFileName()),
+                        from_utf8(savefile.absFileName())));
+       }
        return false;
 }