The unification had been introduced in r12352 and native backend exceptions still slipped through in cases that end in connection.commit() call. Thanks Alex, Jacob and Carl for reviewing. Backport of [14320] from trunk git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@14321 bcc190cf-cafb-0310-a4f2-bffc1f526a37