Checking for filetype=='dir' won't confirm symlinks pointing to a directory

Retrieving a directory listing with function "get_list_of_plugins()" will fail on symlinks.

We have a huge installation with a large number of separated datadirs (but one moodle installation, forced to use different databases, depending on _SERVER[HTTP_HOST]). In order to keep language files out of the www-dir, we use the lang-directories within the different moodledata-dirs. All the Installations should share one language-dir, so we set up symlinks wich point to the master-datadir.

retrieving installed langpacks with moodlelib.php, line 6026:

if (file_exists($basedir) && filetype($basedir) == 'dir') {

will fail in this case. We changed this to

if (file_exists($basedir) && is_dir($basedir)) {

which (for us) works fine.