Add subquery pullup handling for WindowClause runCondition

9d9c02ccd added code to allow WindowAgg to take some shortcuts when a
monotonic WindowFunc reached some value that it could never come back
from due to the function's monotonic nature.  That commit added a
runCondition field to WindowClause to store the condition which, when it
becomes false we can start taking shortcuts in nodeWindowAgg.c.

Here we fix an issue where subquery pullups didn't properly update the
runCondition to update the Vars to properly reference the new query level.

Here we also add a missing call to preprocess_expression() for the
WindowClause's runCondtion.  The WindowFuncs in the targetlist will have
had this process done, so we must also do it for the WindowFuncs in the
runCondition so that they can be correctly found in the targetlist
during setrefs.c

Bug: #17709
Reported-by: Alexey Makhmutov
Author: Richard Guo, David Rowley
Discussion: https://postgr.es/m/[email protected]
Backpatch-through: 15, where 9d9c02ccd was introduced

2 files changed, 12 insertions, 0 deletions

diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 15aa9c5087..5dd4f92720 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -833,6 +833,9 @@ subquery_planner(PlannerGlobal *glob, Query *parse,
 												EXPRKIND_LIMIT);
 		wc->endOffset = preprocess_expression(root, wc->endOffset,
 											  EXPRKIND_LIMIT);
+		wc->runCondition = (List *) preprocess_expression(root,
+														  (Node *) wc->runCondition,
+														  EXPRKIND_TARGET);
 	}
 
 	parse->limitOffset = preprocess_expression(root, parse->limitOffset,
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index 57fea35e44..c2239d18b4 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -2120,6 +2120,15 @@ perform_pullup_replace_vars(PlannerInfo *root,
 		pullup_replace_vars((Node *) parse->targetList, rvcontext);
 	parse->returningList = (List *)
 		pullup_replace_vars((Node *) parse->returningList, rvcontext);
+
+	foreach(lc, parse->windowClause)
+	{
+		WindowClause *wc = lfirst_node(WindowClause, lc);
+
+		if (wc->runCondition != NIL)
+			wc->runCondition = (List *)
+				pullup_replace_vars((Node *) wc->runCondition, rvcontext);
+	}
 	if (parse->onConflict)
 	{
 		parse->onConflict->onConflictSet = (List *)