When using a junkfilter, the output tuple should NOT be stored back into

the same tuple slot that the raw tuple came from, because that slot has
the wrong tuple descriptor.  Store it into its own slot with the correct
descriptor, instead.  This repairs problems with SPI functions seeing
inappropriate tuple descriptors --- for example, plpgsql code failing to
cope with SELECT FOR UPDATE.

1 files changed, 23 insertions, 9 deletions

diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index f87b674b074..3ba9b9136f5 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -27,7 +27,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.141 2001/05/27 09:59:29 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.142 2001/05/27 20:48:51 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -598,12 +598,19 @@ InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate)
 	}
 
 	/*
-	 * initialize the executor "tuple" table.
+	 * initialize the executor "tuple" table.  We need slots for all the
+	 * plan nodes, plus possibly output slots for the junkfilter(s).
+	 * At this point we aren't sure if we need junkfilters, so just add
+	 * slots for them unconditionally.
 	 */
 	{
 		int			nSlots = ExecCountSlotsNode(plan);
 
-		estate->es_tupleTable = ExecCreateTupleTable(nSlots + 10); /* why add ten? - jolly */
+		if (parseTree->resultRelations != NIL)
+			nSlots += length(parseTree->resultRelations);
+		else
+			nSlots += 1;
+		estate->es_tupleTable = ExecCreateTupleTable(nSlots);
 	}
 
 	/* mark EvalPlanQual not active */
@@ -686,7 +693,8 @@ InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate)
 					JunkFilter *j;
 
 					j = ExecInitJunkFilter(subplan->targetlist,
-										   ExecGetTupType(subplan));
+										   ExecGetTupType(subplan),
+										   ExecAllocTableSlot(estate->es_tupleTable));
 					resultRelInfo->ri_junkFilter = j;
 					resultRelInfo++;
 					subplans = lnext(subplans);
@@ -702,9 +710,11 @@ InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate)
 			else
 			{
 				/* Normal case with just one JunkFilter */
-				JunkFilter *j = ExecInitJunkFilter(plan->targetlist,
-												   tupType);
+				JunkFilter *j;
 
+				j = ExecInitJunkFilter(plan->targetlist,
+									   tupType,
+									   ExecAllocTableSlot(estate->es_tupleTable));
 				estate->es_junkFilter = j;
 				if (estate->es_result_relation_info)
 					estate->es_result_relation_info->ri_junkFilter = j;
@@ -986,7 +996,9 @@ lnext:	;
 		 * if we have a junk filter, then project a new tuple with the
 		 * junk removed.
 		 *
-		 * Store this new "clean" tuple in the place of the original tuple.
+		 * Store this new "clean" tuple in the junkfilter's resultSlot.
+		 * (Formerly, we stored it back over the "dirty" tuple, which is
+		 * WRONG because that tuple slot has the wrong descriptor.)
 		 *
 		 * Also, extract all the junk information we need.
 		 */
@@ -1088,7 +1100,7 @@ lnext:	;
 			newTuple = ExecRemoveJunk(junkfilter, slot);
 
 			slot = ExecStoreTuple(newTuple,		/* tuple to store */
-								  slot, /* destination slot */
+								  junkfilter->jf_resultSlot, /* dest slot */
 								  InvalidBuffer,		/* this tuple has no
 														 * buffer */
 								  true);		/* tuple should be pfreed */
@@ -1467,7 +1479,9 @@ lreplace:;
 				{
 					*tupleid = ctid;
 					tuple = ExecRemoveJunk(estate->es_junkFilter, epqslot);
-					slot = ExecStoreTuple(tuple, slot, InvalidBuffer, true);
+					slot = ExecStoreTuple(tuple,
+										  estate->es_junkFilter->jf_resultSlot,
+										  InvalidBuffer, true);
 					goto lreplace;
 				}
 			}