fix: don't follow symlinks when removing junk files (transmission#1638)…

… (transmission#1638)

This prevents accidentally following a symlink that points outside of
the torrent's folder and crawling the rest of the drive for junk files
to remove.

This also prevents symlinks that point to a folder from being treated as
real directories, which would cause them to be removed even if the folder
they point to is not actually empty.

libtransmission/torrent.cc

@@ -2122,7 +2122,7 @@ static void removeEmptyFoldersAndJunkFiles(char const* folder)
             auto const filename = tr_strvPath(folder, name);
 
             auto info = tr_sys_path_info{};
-            if (tr_sys_path_get_info(filename.c_str(), 0, &info, nullptr) && info.type == TR_SYS_PATH_IS_DIRECTORY)
+            if (tr_sys_path_get_info(filename.c_str(), TR_SYS_PATH_NO_FOLLOW, &info, nullptr) && info.type == TR_SYS_PATH_IS_DIRECTORY)
             {
                 removeEmptyFoldersAndJunkFiles(filename.c_str());
             }