Repair bug #2839: the various ExecReScan functions need to reset

ps_TupFromTlist in plan nodes that make use of it.  This was being done
correctly in join nodes and Result nodes but not in any relation-scan nodes.
Bug would lead to bogus results if a set-returning function appeared in the
targetlist of a subquery that could be rescanned after partial execution,
for example a subquery within EXISTS().  Bug has been around forever :-(
... surprising it wasn't reported before.

6 files changed, 20 insertions, 6 deletions

diff --git a/src/backend/executor/nodeFunctionscan.c b/src/backend/executor/nodeFunctionscan.c
index 4cf77dac930..4f95692fe0d 100644
--- a/src/backend/executor/nodeFunctionscan.c
+++ b/src/backend/executor/nodeFunctionscan.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeFunctionscan.c,v 1.29 2004/12/31 21:59:45 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeFunctionscan.c,v 1.29.4.1 2006/12/26 19:27:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -326,6 +326,7 @@ void
 ExecFunctionReScan(FunctionScanState *node, ExprContext *exprCtxt)
 {
 	ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
+	node->ss.ps.ps_TupFromTlist = false;
 
 	/*
 	 * If we haven't materialized yet, just return.
diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c
index afe3a8effa3..e3c97fe572e 100644
--- a/src/backend/executor/nodeIndexscan.c
+++ b/src/backend/executor/nodeIndexscan.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.99.4.1 2006/05/19 16:30:50 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.99.4.2 2006/12/26 19:27:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -405,6 +405,8 @@ ExecIndexReScan(IndexScanState *node, ExprContext *exprCtxt)
 	numScanKeys = node->iss_NumScanKeys;
 	scanrelid = ((IndexScan *) node->ss.ps.plan)->scan.scanrelid;
 
+	node->ss.ps.ps_TupFromTlist = false;
+
 	if (econtext)
 	{
 		/*
@@ -680,6 +682,8 @@ ExecInitIndexScan(IndexScan *node, EState *estate)
 	 */
 	ExecAssignExprContext(estate, &indexstate->ss.ps);
 
+	indexstate->ss.ps.ps_TupFromTlist = false;
+
 	/*
 	 * initialize child expressions
 	 *
diff --git a/src/backend/executor/nodeResult.c b/src/backend/executor/nodeResult.c
index abc94a2cf12..d2ec0deded3 100644
--- a/src/backend/executor/nodeResult.c
+++ b/src/backend/executor/nodeResult.c
@@ -34,7 +34,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeResult.c,v 1.29 2004/12/31 21:59:45 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeResult.c,v 1.29.4.1 2006/12/26 19:27:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -194,6 +194,8 @@ ExecInitResult(Result *node, EState *estate)
 	 */
 	ExecAssignExprContext(estate, &resstate->ps);
 
+	resstate->ps.ps_TupFromTlist = false;
+
 #define RESULT_NSLOTS 1
 
 	/*
diff --git a/src/backend/executor/nodeSeqscan.c b/src/backend/executor/nodeSeqscan.c
index 621911652a9..0a53ce0caac 100644
--- a/src/backend/executor/nodeSeqscan.c
+++ b/src/backend/executor/nodeSeqscan.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeSeqscan.c,v 1.51 2004/12/31 21:59:45 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeSeqscan.c,v 1.51.4.1 2006/12/26 19:27:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -319,6 +319,8 @@ ExecSeqReScan(SeqScanState *node, ExprContext *exprCtxt)
 	estate = node->ps.state;
 	scanrelid = ((SeqScan *) node->ps.plan)->scanrelid;
 
+	node->ps.ps_TupFromTlist = false;
+
 	/* If this is re-scanning of PlanQual ... */
 	if (estate->es_evTuple != NULL &&
 		estate->es_evTuple[scanrelid - 1] != NULL)
diff --git a/src/backend/executor/nodeSubqueryscan.c b/src/backend/executor/nodeSubqueryscan.c
index 9bc5a6294d0..dbdd7c05465 100644
--- a/src/backend/executor/nodeSubqueryscan.c
+++ b/src/backend/executor/nodeSubqueryscan.c
@@ -12,7 +12,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeSubqueryscan.c,v 1.25 2004/12/31 21:59:45 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeSubqueryscan.c,v 1.25.4.1 2006/12/26 19:27:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -278,4 +278,5 @@ ExecSubqueryReScan(SubqueryScanState *node, ExprContext *exprCtxt)
 	MemoryContextSwitchTo(oldcontext);
 
 	node->ss.ss_ScanTupleSlot = NULL;
+	node->ss.ps.ps_TupFromTlist = false;
 }
diff --git a/src/backend/executor/nodeTidscan.c b/src/backend/executor/nodeTidscan.c
index a1eb4351dbb..1cc361cfe5a 100644
--- a/src/backend/executor/nodeTidscan.c
+++ b/src/backend/executor/nodeTidscan.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeTidscan.c,v 1.41 2004/12/31 21:59:45 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeTidscan.c,v 1.41.4.1 2006/12/26 19:27:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -276,6 +276,8 @@ ExecTidReScan(TidScanState *node, ExprContext *exprCtxt)
 	estate = node->ss.ps.state;
 	scanrelid = ((TidScan *) node->ss.ps.plan)->scan.scanrelid;
 
+	node->ss.ps.ps_TupFromTlist = false;
+
 	/* If we are being passed an outer tuple, save it for runtime key calc */
 	if (exprCtxt != NULL)
 		node->ss.ps.ps_ExprContext->ecxt_outertuple =
@@ -391,6 +393,8 @@ ExecInitTidScan(TidScan *node, EState *estate)
 	 */
 	ExecAssignExprContext(estate, &tidstate->ss.ps);
 
+	tidstate->ss.ps.ps_TupFromTlist = false;
+
 	/*
 	 * initialize child expressions
 	 */