Call to dict_keys_join dereferences xattr before it is checked for NULL. Restructured the function to check for NULL earlier and call dict_unref only when needed. BUG: 789278 CID: 1124826 Change-Id: I732fa304ad6f3b921c589832d13f73bbd36f589c Signed-off-by: Jose A. Rivera <jarrpa@redhat.com> Reviewed-on: http://review.gluster.org/6763 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Vijay Bellur <vbellur@redhat.com>