Fix delete_object and write convergence in transaction.

Fix a bug, when delete_object was deleting the record if it was written
in the same transaction even if it was written to a different value.

To verify:
%% Create a set table
mnesia:create_table(foo, []).

%% Write and delete_object in transaction
mnesia:transaction(fun() ->
    mnesia:write({foo, bar, one}),
    mnesia:delete_object({foo, bar, not_one})
end).

{atomic, [{foo, bar, one}]} = mnesia:transaction(fun() -> mnesia:read(foo, bar) end).

Added a section to isolation tests to check for non-matching delete_object
requests.

1 files changed, 10 insertions, 6 deletions

diff --git a/lib/mnesia/src/mnesia.erl b/lib/mnesia/src/mnesia.erl
index e298904e2a..df3a2dfe6f 100644
--- a/lib/mnesia/src/mnesia.erl
+++ b/lib/mnesia/src/mnesia.erl
@@ -779,12 +779,16 @@ do_delete_object(Tid, Ts, Tab, Val, LockKind) ->
 		      ?ets_insert(Store, {Oid, Val, delete_object});
 		  _ ->
 		      case ?ets_match_object(Store, {Oid, '_', write}) of
-			  [] ->
-			      ?ets_match_delete(Store, {Oid, Val, '_'}),
-			      ?ets_insert(Store, {Oid, Val, delete_object});
-			  _  ->
-			      ?ets_delete(Store, Oid),
-			      ?ets_insert(Store, {Oid, Oid, delete})
+			      [] ->
+			          ?ets_match_delete(Store, {Oid, Val, '_'}),
+			          ?ets_insert(Store, {Oid, Val, delete_object});
+			      Ops  ->
+			          case lists:member({Oid, Val, write}, Ops) of
+			              true ->
+			                  ?ets_delete(Store, Oid),
+			                  ?ets_insert(Store, {Oid, Oid, delete});
+			              false -> ok
+			          end
 		      end
 	      end,
 	      ok;