MDEV-38694 [check-ci] Clean up unfinished spider bg thread in index_end

Author: mariadb-YuchenPei

sql/ha_partition.cc

@@ -6094,7 +6094,7 @@ int ha_partition::common_index_read(uchar *buf, bool have_start_key)
       The unordered index scan will use the partition set created.
     */
     DBUG_PRINT("info", ("doing unordered scan"));
-    error= handle_pre_scan(reverse_order, FALSE);
+    error= handle_pre_scan(reverse_order, check_parallel_search());
     if (likely(!error))
       error= handle_unordered_scan_next_partition(buf, reverse_order);
   }

storage/spider/ha_spider.cc

@@ -1227,6 +1227,9 @@ int ha_spider::index_end()
   backup_error_status();
   DBUG_ENTER("ha_spider::index_end");
   DBUG_PRINT("info",("spider this=%p", this));
+  if (result_list.bgs_working &&
+      (error_num = spider_bg_all_conn_pre_next(this, search_link_idx)))
+    DBUG_RETURN(error_num);
   active_index = MAX_KEY;
   if ((error_num = drop_tmp_tables()))
     DBUG_RETURN(check_error_mode(error_num));