Merge 10.2 to 10.3

Temporarily disable main.cte_recursive due to hang in
an added test related to MDEV-15575.

1 files changed, 18 insertions, 13 deletions

diff --git a/sql/sql_union.cc b/sql/sql_union.cc
index 0149c2848c2..4cc7de8897d 100644
--- a/sql/sql_union.cc
+++ b/sql/sql_union.cc
@@ -413,19 +413,13 @@ select_union_recursive::create_result_table(THD *thd_arg,
   if (! (incr_table= create_tmp_table(thd_arg, &tmp_table_param, *column_types,
                                       (ORDER*) 0, false, 1,
                                       options, HA_POS_ERROR, &empty_clex_str,
-                                      !create_table, keep_row_order)))
+                                      true, keep_row_order)))
     return true;
 
   incr_table->keys_in_use_for_query.clear_all();
   for (uint i=0; i < table->s->fields; i++)
     incr_table->field[i]->flags &= ~PART_KEY_FLAG;
 
-  if (create_table)
-  {
-    incr_table->file->extra(HA_EXTRA_WRITE_CACHE);
-    incr_table->file->extra(HA_EXTRA_IGNORE_DUP_KEY);
-  }
-
   TABLE *rec_table= 0;
   if (! (rec_table= create_tmp_table(thd_arg, &tmp_table_param, *column_types,
                                      (ORDER*) 0, false, 1,
@@ -469,8 +463,11 @@ void select_union_recursive::cleanup()
 
   if (incr_table)
   {
-    incr_table->file->extra(HA_EXTRA_RESET_STATE);
-    incr_table->file->ha_delete_all_rows();
+    if (incr_table->is_created())
+    {
+      incr_table->file->extra(HA_EXTRA_RESET_STATE);
+      incr_table->file->ha_delete_all_rows();
+    }
     free_tmp_table(thd, incr_table);
   }
 
@@ -1659,16 +1656,24 @@ bool st_select_lex_unit::exec_recursive()
   if (!was_executed)
     save_union_explain(thd->lex->explain);
 
-  if ((saved_error= incr_table->file->ha_delete_all_rows()))
-    goto err;
-
   if (with_element->level == 0)
   {
+    if (!incr_table->is_created() &&
+        instantiate_tmp_table(incr_table,
+                              tmp_table_param->keyinfo,
+                              tmp_table_param->start_recinfo,
+                              &tmp_table_param->recinfo,
+                              0))
+      DBUG_RETURN(1);
+    incr_table->file->extra(HA_EXTRA_WRITE_CACHE);
+    incr_table->file->extra(HA_EXTRA_IGNORE_DUP_KEY);
     start= first_select();
     if (with_element->with_anchor)
       end= with_element->first_recursive;
   }
-   
+  else if ((saved_error= incr_table->file->ha_delete_all_rows()))
+    goto err;
+
   for (st_select_lex *sl= start ; sl != end; sl= sl->next_select())
   {
     if (with_element->level)