Ensure that INSERT ... SELECT into a table with OIDs never copies row OIDs

from the source table.  This could never happen anyway before 8.4 because
the executor invariably applied a "junk filter" to rows due to be inserted;
but now that we skip doing that when it's not necessary, the case can occur.
Problem noted 2008-11-27 by KaiGai Kohei, though I misunderstood what he
was on about at the time (the opacity of the patch he proposed didn't help).

diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 41b6737049b00282ff3a8bca88441ce4d14969b2..2ff4150f601a1af4225c30629bf5e366ca7e022e 100644 (file)
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -26,7 +26,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.322 2009/02/02 19:31:39 alvherre Exp $
+ *   $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.323 2009/02/08 18:02:27 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1766,6 +1766,21 @@ ExecInsert(TupleTableSlot *slot,
    resultRelInfo = estate->es_result_relation_info;
    resultRelationDesc = resultRelInfo->ri_RelationDesc;
 
+   /*
+    * If the result relation has OIDs, force the tuple's OID to zero so that
+    * heap_insert will assign a fresh OID.  Usually the OID already will be
+    * zero at this point, but there are corner cases where the plan tree can
+    * return a tuple extracted literally from some table with the same
+    * rowtype.
+    *
+    * XXX if we ever wanted to allow users to assign their own OIDs to new
+    * rows, this'd be the place to do it.  For the moment, we make a point
+    * of doing this before calling triggers, so that a user-supplied trigger
+    * could hack the OID if desired.
+    */
+   if (resultRelationDesc->rd_rel->relhasoids)
+       HeapTupleSetOid(tuple, InvalidOid);
+
    /* BEFORE ROW INSERT Triggers */
    if (resultRelInfo->ri_TrigDesc &&
        resultRelInfo->ri_TrigDesc->n_before_row[TRIGGER_EVENT_INSERT] > 0)
@@ -3033,6 +3048,12 @@ intorel_receive(TupleTableSlot *slot, DestReceiver *self)
     */
    tuple = ExecMaterializeSlot(slot);
 
+   /*
+    * force assignment of new OID (see comments in ExecInsert)
+    */
+   if (myState->rel->rd_rel->relhasoids)
+       HeapTupleSetOid(tuple, InvalidOid);
+
    heap_insert(myState->rel,
                tuple,
                myState->estate->es_output_cid,