Merge pull request #18 from cystbear/fix-mnesia-backend

added invariant case to store_mnesia:delete/2

src/store_mnesia.erl

@@ -37,7 +37,8 @@ put(Record) -> put([Record]).
 delete(Tab, Key) ->
     case mnesia:activity(context(),fun()-> mnesia:delete({Tab, Key}) end) of
         {aborted,Reason} -> {error,Reason};
-        {atomic,_Result} -> ok end.
+        {atomic,_Result} -> ok;
+        X -> X end.
 count(RecordName) -> mnesia:table_info(RecordName, size).
 all(R) -> lists:flatten(many(fun() -> L= mnesia:all_keys(R), [ mnesia:read({R, G}) || G <- L ] end)).
 next_id(RecordName, Incr) -> mnesia:dirty_update_counter({id_seq, RecordName}, Incr).