There is a cut and paste error where the check is made against the user id and not against the group id when checking whether the duplicate entry already exists. Hence we can fail to create the entry, possibly creating permission problems when chnanging the group owner of the file/directory.
Created attachment 8291 [details]
patch cherry-picked from master
This is the obvious fix from master. with cherry-pick-info
OK. this was actually already fixed, but since the order of patches was reversed, I undid the patch in my patch for bug #9462. gonna fix that patchset...