563365 - Error handling problems in the backend functions
    
    https://bugzilla.redhat.com/show_bug.cgi?id=563365
    
    Error handling in ldbm_back_{add,delete,modify,modrdn} functions was
    incomplete.  When any error occurs after the transaction begins, the
    changes made after that should be aborted.  There were some cases the
    abort was not called.