Read parents list before it could lead to segfault

Author: ildus

src/include/compat/pg_compat.h

@@ -322,7 +322,7 @@ static inline void mult_result_handler() { elog(ERROR, ERR_PART_ATTR_MULTIPLE_RE
 /*
  * extract_actual_join_clauses()
  */
-#if (PG_VERSION_NUM >= 100004) || \
+#if (PG_VERSION_NUM >= 100003) || \
 	(PG_VERSION_NUM <  100000 && PG_VERSION_NUM >= 90609) || \
 	(PG_VERSION_NUM <   90600 && PG_VERSION_NUM >= 90513)
 #define extract_actual_join_clauses_compat(restrictinfo_list, \

src/relation_info.c

@@ -991,7 +991,6 @@ finish_delayed_invalidation(void)
 	{
 		Oid		   *parents = NULL;
 		int			parents_count = 0;
-		bool		parents_fetched = false;
 		ListCell   *lc;
 
 		AcceptInvalidationMessages();
@@ -1017,26 +1016,19 @@ finish_delayed_invalidation(void)
 
 				/* Disregard all remaining invalidation jobs */
 				delayed_invalidation_whole_cache = false;
-				free_invalidation_lists();
 
-				/* No need to continue, exit */
-				return;
+				goto end;
 			}
 		}
 
+		parents = read_parent_oids(&parents_count);
+
 		/* We might be asked to perform a complete cache invalidation */
 		if (delayed_invalidation_whole_cache)
 		{
 			/* Unset 'invalidation_whole_cache' flag */
 			delayed_invalidation_whole_cache = false;
 
-			/* Fetch all partitioned tables */
-			if (!parents_fetched)
-			{
-				parents = read_parent_oids(&parents_count);
-				parents_fetched = true;
-			}
-
 			/* Invalidate live entries and remove dead ones */
 			invalidate_pathman_relation_info_cache(parents, parents_count);
 		}
@@ -1050,13 +1042,6 @@ finish_delayed_invalidation(void)
 			if (IsToastNamespace(get_rel_namespace(parent)))
 				continue;
 
-			/* Fetch all partitioned tables */
-			if (!parents_fetched)
-			{
-				parents = read_parent_oids(&parents_count);
-				parents_fetched = true;
-			}
-
 			/* Check if parent still exists */
 			if (bsearch_oid(parent, parents, parents_count))
 				/* get_pathman_relation_info() will refresh this entry */
@@ -1074,13 +1059,6 @@ finish_delayed_invalidation(void)
 			if (IsToastNamespace(get_rel_namespace(vague_rel)))
 				continue;
 
-			/* Fetch all partitioned tables */
-			if (!parents_fetched)
-			{
-				parents = read_parent_oids(&parents_count);
-				parents_fetched = true;
-			}
-
 			/* It might be a partitioned table or a partition */
 			if (!try_invalidate_parent(vague_rel, parents, parents_count))
 			{
@@ -1117,6 +1095,7 @@ finish_delayed_invalidation(void)
 			}
 		}
 
+end:
 		/* Finally, free invalidation jobs lists */
 		free_invalidation_lists();