do not rename() .map symlinks, but just overwrite them

If the user uses symlinks (perhaps from a carefully constructed CVS path),
we would break the symlink when saving the map file. Do not write a .bak
file in this case and just overwrite the symlink target.

diff --git a/radiant/referencecache.cpp b/radiant/referencecache.cpp
index 9ceeba1bc78fe0e0578d2d3ec97dca2459afa951..cf5abe0c928e3526af1c5eee979b8c42e0f94372 100644 (file)
--- a/radiant/referencecache.cpp
+++ b/radiant/referencecache.cpp
@@ -124,8 +124,7 @@ bool file_saveBackup( const char* path ){
                StringOutputStream backup( 256 );
                backup << StringRange( path, path_get_extension( path ) ) << "bak";
 
-               return ( !file_exists( backup.c_str() ) || file_remove( backup.c_str() ) ) // remove backup
-                          && file_move( path, backup.c_str() ); // rename current to backup
+               return file_move( path, backup.c_str() ); // rename current to backup
        }
 
        globalErrorStream() << "map path is not writeable: " << makeQuoted( path ) << "\n";
@@ -137,7 +136,21 @@ bool MapResource_save( const MapFormat& format, scene::Node& root, const char* p
        fullpath << path << name;
 
        if ( path_is_absolute( fullpath.c_str() ) ) {
-               if ( !file_exists( fullpath.c_str() ) || file_saveBackup( fullpath.c_str() ) ) {
+               /* We don't want a backup + rename operation if the .map file is
+                * a symlink. Otherwise we'll break the user's careful symlink setup.
+                * Just overwrite the original file. Assume the user has versioning. */
+               bool make_backup;
+               struct stat st;
+               if ( lstat(fullpath.c_str(), &st) == 0 ) {
+                       make_backup = true;             // file exists
+                       if ( (st.st_mode & S_IFMT) == S_IFLNK ) {
+                               make_backup = false;    // .. but it is a symlink
+                       }
+               } else {
+                       make_backup = false;            // nothing to move
+               }
+
+               if ( !make_backup || file_saveBackup( fullpath.c_str() ) ) {
                        return MapResource_saveFile( format, root, Map_Traverse, fullpath.c_str() );
                }