Add missed bms_copy() in perform_pruning_combine_step

alvherre · alvherre · commit 7ba6ee815dc9 · 2018-04-09T10:54:28.000-03:00
We were initializing a BMS to merely reference an existing one, which would cause a double-free (and a crash) when the recursive algorithm tried to intersect it with an empty one. Fix it by creating a copy at initialization time. Reported-by: sqlsmith (by way of Andreas Seltenreich) Author: Amit Langote Discussion: https://postgr.es/m/87in923lyw.fsf@ansel.ydns.eu
diff --git a/src/backend/partitioning/partprune.c b/src/backend/partitioning/partprune.c
@@ -2923,7 +2923,8 @@ perform_pruning_combine_step(PartitionPruneContext *context,
 				if (firststep)
 				{
 					/* Copy step's result the first time. */
-					result->bound_offsets = step_result->bound_offsets;
+					result->bound_offsets =
+						bms_copy(step_result->bound_offsets);
 					result->scan_null = step_result->scan_null;
 					result->scan_default = step_result->scan_default;
 					firststep = false;
