Fix brown-paper-bag bug in commit 0a459cec96d3856f476c2db298c6b52f592894e8.

RANGE_OFFSET comparisons need to examine the first ORDER BY column,
which isn't necessarily the first column in the incoming tuples.
No idea how this slipped through initial testing.

Per bug #15082 from Zhou Digoal.

Discussion: https://postgr.es/m/151939899974.1461.9411971793110285476@wrigleys.postgresql.org

diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index a56c3e89fd5f661d05d9856b45883f8d1d112151..fe5369a0c7b70ea338fa38adc43f9985f860581a 100644 (file)
--- a/src/backend/executor/nodeWindowAgg.c
+++ b/src/backend/executor/nodeWindowAgg.c
@@ -1559,6 +1559,7 @@ update_frameheadpos(WindowAggState *winstate)
             * reach end of partition, we will leave frameheadpos = end+1 and
             * framehead_slot empty.
             */
+           int         sortCol = node->ordColIdx[0];
            bool        sub,
                        less;
 
@@ -1593,9 +1594,9 @@ update_frameheadpos(WindowAggState *winstate)
                bool        headisnull,
                            currisnull;
 
-               headval = slot_getattr(winstate->framehead_slot, 1,
+               headval = slot_getattr(winstate->framehead_slot, sortCol,
                                       &headisnull);
-               currval = slot_getattr(winstate->ss.ss_ScanTupleSlot, 1,
+               currval = slot_getattr(winstate->ss.ss_ScanTupleSlot, sortCol,
                                       &currisnull);
                if (headisnull || currisnull)
                {
@@ -1809,6 +1810,7 @@ update_frametailpos(WindowAggState *winstate)
             * necessary.  Note that if we reach end of partition, we will
             * leave frametailpos = end+1 and frametail_slot empty.
             */
+           int         sortCol = node->ordColIdx[0];
            bool        sub,
                        less;
 
@@ -1843,9 +1845,9 @@ update_frametailpos(WindowAggState *winstate)
                bool        tailisnull,
                            currisnull;
 
-               tailval = slot_getattr(winstate->frametail_slot, 1,
+               tailval = slot_getattr(winstate->frametail_slot, sortCol,
                                       &tailisnull);
-               currval = slot_getattr(winstate->ss.ss_ScanTupleSlot, 1,
+               currval = slot_getattr(winstate->ss.ss_ScanTupleSlot, sortCol,
                                       &currisnull);
                if (tailisnull || currisnull)
                {