Use outerPlanState macro instead of referring to leffttree.

This makes the executor code more consistent.  It also removes
an apparently superfluous NULL test in nodeGroup.c.

Qingqing Zhou, reviewed by Tom Lane, and further revised by me.

6 files changed, 27 insertions, 18 deletions

diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index 9ff0eff6d7b..4a8af7b3a7e 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -2053,6 +2053,7 @@ void
 ExecReScanAgg(AggState *node)
 {
 	ExprContext *econtext = node->ss.ps.ps_ExprContext;
+	PlanState	*outerPlan = outerPlanState(node);
 	int			aggno;
 
 	node->agg_done = false;
@@ -2075,7 +2076,7 @@ ExecReScanAgg(AggState *node)
 		 * parameter changes, then we can just rescan the existing hash table;
 		 * no need to build it again.
 		 */
-		if (node->ss.ps.lefttree->chgParam == NULL)
+		if (outerPlan->chgParam == NULL)
 		{
 			ResetTupleHashIterator(node->hashtable, &node->hashiter);
 			return;
@@ -2133,8 +2134,8 @@ ExecReScanAgg(AggState *node)
 	 * if chgParam of subnode is not null then plan will be re-scanned by
 	 * first ExecProcNode.
 	 */
-	if (node->ss.ps.lefttree->chgParam == NULL)
-		ExecReScan(node->ss.ps.lefttree);
+	if (outerPlan->chgParam == NULL)
+		ExecReScan(outerPlan);
 }
 
 
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
index 8ea8b9f16be..40a06f163a6 100644
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -449,6 +449,8 @@ ExecBitmapHeapScan(BitmapHeapScanState *node)
 void
 ExecReScanBitmapHeapScan(BitmapHeapScanState *node)
 {
+	PlanState	*outerPlan = outerPlanState(node);
+
 	/* rescan to release any page pin */
 	heap_rescan(node->ss.ss_currentScanDesc, NULL);
 
@@ -469,8 +471,8 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node)
 	 * if chgParam of subnode is not null then plan will be re-scanned by
 	 * first ExecProcNode.
 	 */
-	if (node->ss.ps.lefttree->chgParam == NULL)
-		ExecReScan(node->ss.ps.lefttree);
+	if (outerPlan->chgParam == NULL)
+		ExecReScan(outerPlan);
 }
 
 /* ----------------------------------------------------------------
diff --git a/src/backend/executor/nodeGroup.c b/src/backend/executor/nodeGroup.c
index 83d562e5119..3f87716b8f1 100644
--- a/src/backend/executor/nodeGroup.c
+++ b/src/backend/executor/nodeGroup.c
@@ -280,6 +280,8 @@ ExecEndGroup(GroupState *node)
 void
 ExecReScanGroup(GroupState *node)
 {
+	PlanState	*outerPlan = outerPlanState(node);
+
 	node->grp_done = FALSE;
 	node->ss.ps.ps_TupFromTlist = false;
 	/* must clear first tuple */
@@ -289,7 +291,6 @@ ExecReScanGroup(GroupState *node)
 	 * if chgParam of subnode is not null then plan will be re-scanned by
 	 * first ExecProcNode.
 	 */
-	if (node->ss.ps.lefttree &&
-		node->ss.ps.lefttree->chgParam == NULL)
-		ExecReScan(node->ss.ps.lefttree);
+	if (outerPlan->chgParam == NULL)
+		ExecReScan(outerPlan);
 }
diff --git a/src/backend/executor/nodeMaterial.c b/src/backend/executor/nodeMaterial.c
index 11588258694..8ff4352a66a 100644
--- a/src/backend/executor/nodeMaterial.c
+++ b/src/backend/executor/nodeMaterial.c
@@ -317,6 +317,8 @@ ExecMaterialRestrPos(MaterialState *node)
 void
 ExecReScanMaterial(MaterialState *node)
 {
+	PlanState	*outerPlan = outerPlanState(node);
+
 	ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
 
 	if (node->eflags != 0)
@@ -339,13 +341,13 @@ ExecReScanMaterial(MaterialState *node)
 		 * Otherwise we can just rewind and rescan the stored output. The
 		 * state of the subnode does not change.
 		 */
-		if (node->ss.ps.lefttree->chgParam != NULL ||
+		if (outerPlan->chgParam != NULL ||
 			(node->eflags & EXEC_FLAG_REWIND) == 0)
 		{
 			tuplestore_end(node->tuplestorestate);
 			node->tuplestorestate = NULL;
-			if (node->ss.ps.lefttree->chgParam == NULL)
-				ExecReScan(node->ss.ps.lefttree);
+			if (outerPlan->chgParam == NULL)
+				ExecReScan(outerPlan);
 			node->eof_underlying = false;
 		}
 		else
@@ -359,8 +361,8 @@ ExecReScanMaterial(MaterialState *node)
 		 * if chgParam of subnode is not null then plan will be re-scanned by
 		 * first ExecProcNode.
 		 */
-		if (node->ss.ps.lefttree->chgParam == NULL)
-			ExecReScan(node->ss.ps.lefttree);
+		if (outerPlan->chgParam == NULL)
+			ExecReScan(outerPlan);
 		node->eof_underlying = false;
 	}
 }
diff --git a/src/backend/executor/nodeSort.c b/src/backend/executor/nodeSort.c
index a815cde2ccf..732f3c38dbb 100644
--- a/src/backend/executor/nodeSort.c
+++ b/src/backend/executor/nodeSort.c
@@ -290,6 +290,8 @@ ExecSortRestrPos(SortState *node)
 void
 ExecReScanSort(SortState *node)
 {
+	PlanState	*outerPlan = outerPlanState(node);
+
 	/*
 	 * If we haven't sorted yet, just return. If outerplan's chgParam is not
 	 * NULL then it will be re-scanned by ExecProcNode, else no reason to
@@ -308,7 +310,7 @@ ExecReScanSort(SortState *node)
 	 *
 	 * Otherwise we can just rewind and rescan the sorted output.
 	 */
-	if (node->ss.ps.lefttree->chgParam != NULL ||
+	if (outerPlan->chgParam != NULL ||
 		node->bounded != node->bounded_Done ||
 		node->bound != node->bound_Done ||
 		!node->randomAccess)
@@ -321,8 +323,8 @@ ExecReScanSort(SortState *node)
 		 * if chgParam of subnode is not null then plan will be re-scanned by
 		 * first ExecProcNode.
 		 */
-		if (node->ss.ps.lefttree->chgParam == NULL)
-			ExecReScan(node->ss.ps.lefttree);
+		if (outerPlan->chgParam == NULL)
+			ExecReScan(outerPlan);
 	}
 	else
 		tuplesort_rescan((Tuplesortstate *) node->tuplesortstate);
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index a06790d94a1..bf0c98d8783 100644
--- a/src/backend/executor/nodeWindowAgg.c
+++ b/src/backend/executor/nodeWindowAgg.c
@@ -2057,6 +2057,7 @@ ExecEndWindowAgg(WindowAggState *node)
 void
 ExecReScanWindowAgg(WindowAggState *node)
 {
+	PlanState	*outerPlan = outerPlanState(node);
 	ExprContext *econtext = node->ss.ps.ps_ExprContext;
 
 	node->all_done = false;
@@ -2082,8 +2083,8 @@ ExecReScanWindowAgg(WindowAggState *node)
 	 * if chgParam of subnode is not null then plan will be re-scanned by
 	 * first ExecProcNode.
 	 */
-	if (node->ss.ps.lefttree->chgParam == NULL)
-		ExecReScan(node->ss.ps.lefttree);
+	if (outerPlan->chgParam == NULL)
+		ExecReScan(outerPlan);
 }
 
 /*