Fix another problem in 8.2 changes that allowed "one-time" qual conditions to

be checked at plan levels below the top; namely, we have to allow for Result
nodes inserted just above a nestloop inner indexscan.  Should think about
using the general Param mechanism to pass down outer-relation variables, but
for the moment we need a back-patchable solution.  Per report from Phil Frost.

Author: tglsfdc

src/backend/executor/nodeResult.c

@@ -38,7 +38,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeResult.c,v 1.38 2007/02/15 03:07:13 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeResult.c,v 1.39 2007/02/16 03:49:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -309,10 +309,12 @@ ExecReScanResult(ResultState *node, ExprContext *exprCtxt)
 	node->rs_checkqual = (node->resconstantqual == NULL) ? false : true;
 
 	/*
-	 * if chgParam of subnode is not null then plan will be re-scanned by
-	 * first ExecProcNode.
+	 * If chgParam of subnode is not null then plan will be re-scanned by
+	 * first ExecProcNode.  However, if caller is passing us an exprCtxt
+	 * then forcibly rescan the subnode now, so that we can pass the
+	 * exprCtxt down to the subnode (needed for gated indexscan).
 	 */
-	if (((PlanState *) node)->lefttree &&
-		((PlanState *) node)->lefttree->chgParam == NULL)
-		ExecReScan(((PlanState *) node)->lefttree, exprCtxt);
+	if (node->ps.lefttree &&
+		(node->ps.lefttree->chgParam == NULL || exprCtxt != NULL))
+		ExecReScan(node->ps.lefttree, exprCtxt);
 }

src/backend/optimizer/plan/setrefs.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/plan/setrefs.c,v 1.128 2007/01/22 01:35:20 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/plan/setrefs.c,v 1.129 2007/02/16 03:49:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -936,6 +936,14 @@ set_inner_join_references(Plan *inner_plan, indexed_tlist *outer_itlist)
 									  outer_itlist);
 		}
 	}
+	else if (IsA(inner_plan, Result))
+	{
+		/* Recurse through a gating Result node (similar to Append case) */
+		Result	   *result = (Result *) inner_plan;
+
+		if (result->plan.lefttree)
+			set_inner_join_references(result->plan.lefttree, outer_itlist);
+	}
 	else if (IsA(inner_plan, TidScan))
 	{
 		TidScan    *innerscan = (TidScan *) inner_plan;