Index: src/backend/utils/adt/trigfuncs.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/trigfuncs.c,v
retrieving revision 1.2
diff -c -r1.2 trigfuncs.c
*** src/backend/utils/adt/trigfuncs.c	4 Nov 2008 00:29:39 -0000	1.2
--- src/backend/utils/adt/trigfuncs.c	5 Nov 2008 17:30:26 -0000
***************
*** 30,35 ****
--- 30,36 ----
      TriggerData *trigdata = (TriggerData *) fcinfo->context;
      HeapTuple   newtuple, oldtuple, rettuple;
  	HeapTupleHeader newheader, oldheader;
+ 	Oid oldoid = InvalidOid;
  
      /* make sure it's called as a trigger */
      if (!CALLED_AS_TRIGGER(fcinfo))
***************
*** 62,67 ****
--- 63,74 ----
  	newheader = newtuple->t_data;
  	oldheader = oldtuple->t_data;
  
+  	if (oldheader->t_infomask & HEAP_HASOID)
+ 	{
+ 		oldoid = HeapTupleHeaderGetOid(oldheader);
+ 		HeapTupleHeaderSetOid(oldheader, InvalidOid);
+ 	}
+ 
  	/* if the tuple payload is the same ... */
      if (newtuple->t_len == oldtuple->t_len &&
  		newheader->t_hoff == oldheader->t_hoff &&
***************
*** 76,81 ****
--- 83,93 ----
  		/* ... then suppress the update */
  		rettuple = NULL;
  	}
+  	else if (oldheader->t_infomask & HEAP_HASOID)
+ 	{
+ 		HeapTupleHeaderSetOid(oldheader, oldoid);
+ 	}
+ 	
  	
      return PointerGetDatum(rettuple);
  }
Index: src/test/regress/expected/triggers.out
===================================================================
RCS file: /cvsroot/pgsql/src/test/regress/expected/triggers.out,v
retrieving revision 1.25
diff -c -r1.25 triggers.out
*** src/test/regress/expected/triggers.out	3 Nov 2008 20:17:20 -0000	1.25
--- src/test/regress/expected/triggers.out	5 Nov 2008 17:30:27 -0000
***************
*** 542,551 ****
--- 542,559 ----
  	f1	text,
  	f2 int,
  	f3 int);
+ CREATE TABLE min_updates_test_oids (
+ 	f1	text,
+ 	f2 int,
+ 	f3 int) WITH OIDS;
  INSERT INTO min_updates_test VALUES ('a',1,2),('b','2',null);
+ INSERT INTO min_updates_test_oids VALUES ('a',1,2),('b','2',null);
  CREATE TRIGGER z_min_update 
  BEFORE UPDATE ON min_updates_test
  FOR EACH ROW EXECUTE PROCEDURE suppress_redundant_updates_trigger();
+ CREATE TRIGGER z_min_update 
+ BEFORE UPDATE ON min_updates_test_oids
+ FOR EACH ROW EXECUTE PROCEDURE suppress_redundant_updates_trigger();
  \set QUIET false
  UPDATE min_updates_test SET f1 = f1;
  UPDATE 0
***************
*** 553,558 ****
--- 561,572 ----
  UPDATE 2
  UPDATE min_updates_test SET f3 = 2 WHERE f3 is null;
  UPDATE 1
+ UPDATE min_updates_test_oids SET f1 = f1;
+ UPDATE 0
+ UPDATE min_updates_test_oids SET f2 = f2 + 1;
+ UPDATE 2
+ UPDATE min_updates_test_oids SET f3 = 2 WHERE f3 is null;
+ UPDATE 1
  \set QUIET true
  SELECT * FROM min_updates_test;
   f1 | f2 | f3 
***************
*** 561,564 ****
--- 575,586 ----
   b  |  3 |  2
  (2 rows)
  
+ SELECT * FROM min_updates_test_oids;
+  f1 | f2 | f3 
+ ----+----+----
+  a  |  2 |  2
+  b  |  3 |  2
+ (2 rows)
+ 
  DROP TABLE min_updates_test;
+ DROP TABLE min_updates_test_oids;
Index: src/test/regress/sql/triggers.sql
===================================================================
RCS file: /cvsroot/pgsql/src/test/regress/sql/triggers.sql,v
retrieving revision 1.14
diff -c -r1.14 triggers.sql
*** src/test/regress/sql/triggers.sql	3 Nov 2008 20:17:21 -0000	1.14
--- src/test/regress/sql/triggers.sql	5 Nov 2008 17:30:27 -0000
***************
*** 424,435 ****
--- 424,446 ----
  	f2 int,
  	f3 int);
  
+ CREATE TABLE min_updates_test_oids (
+ 	f1	text,
+ 	f2 int,
+ 	f3 int) WITH OIDS;
+ 
  INSERT INTO min_updates_test VALUES ('a',1,2),('b','2',null);
  
+ INSERT INTO min_updates_test_oids VALUES ('a',1,2),('b','2',null);
+ 
  CREATE TRIGGER z_min_update 
  BEFORE UPDATE ON min_updates_test
  FOR EACH ROW EXECUTE PROCEDURE suppress_redundant_updates_trigger();
  
+ CREATE TRIGGER z_min_update 
+ BEFORE UPDATE ON min_updates_test_oids
+ FOR EACH ROW EXECUTE PROCEDURE suppress_redundant_updates_trigger();
+ 
  \set QUIET false
  
  UPDATE min_updates_test SET f1 = f1;
***************
*** 438,446 ****
--- 449,467 ----
  
  UPDATE min_updates_test SET f3 = 2 WHERE f3 is null;
  
+ UPDATE min_updates_test_oids SET f1 = f1;
+ 
+ UPDATE min_updates_test_oids SET f2 = f2 + 1;
+ 
+ UPDATE min_updates_test_oids SET f3 = 2 WHERE f3 is null;
+ 
  \set QUIET true
  
  SELECT * FROM min_updates_test;
  
+ SELECT * FROM min_updates_test_oids;
+ 
  DROP TABLE min_updates_test;
  
+ DROP TABLE min_updates_test_oids;
+