Merge 10.1 into 10.1

This is joint work with Oleksandr Byelkin.

1 files changed, 12 insertions, 10 deletions

diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index bfaa0a60a24..f98a7b7e474 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -15699,19 +15699,21 @@ subselect_end:
             lex->current_select = lex->current_select->return_after_parsing();
             lex->nest_level--;
             lex->current_select->n_child_sum_items += child->n_sum_items;
-            /*
-              A subselect can add fields to an outer select. Reserve space for
-              them.
-            */
-            lex->current_select->select_n_where_fields+=
-            child->select_n_where_fields;
 
             /*
-              Aggregate functions in having clause may add fields to an outer
-              select. Count them also.
+              A subquery (and all the subsequent query blocks in a UNION) can
+              add columns to an outer query block. Reserve space for them.
+              Aggregate functions in having clause can also add fields to an
+              outer select.
             */
-            lex->current_select->select_n_having_items+=
-            child->select_n_having_items;
+            for (SELECT_LEX *temp= child->master_unit()->first_select();
+                 temp != NULL; temp= temp->next_select())
+            {
+              lex->current_select->select_n_where_fields+=
+                temp->select_n_where_fields;
+              lex->current_select->select_n_having_items+=
+                temp->select_n_having_items;
+            }
           }
         ;