- addendum of the fix for bug 27786:

  applied the new function is_union() to places
  in the code that check the same condition.
- 5.0->5.1 merge fixes


mysql-test/r/subselect3.result:
  merge 5.0->5.1 : updated explain.
sql/item_subselect.cc:
  addendum of the fix for bug 27786:
  applied the new function is_union() to the applicable places.
sql/sql_derived.cc:
  addendum of the fix for bug 27786:
  applied the new function is_union() to the applicable places.
sql/sql_parse.cc:
  addendum of the fix for bug 27786:
  applied the new function is_union() to the applicable places.
sql/sql_select.cc:
  addendum of the fix for bug 27786:
  applied the new function is_union() to places 
  in the code that check the same condition.
sql/sql_union.cc:
  addendum of the fix for bug 27786:
  applied the new function is_union() to the applicable places.
sql/sql_view.cc:
  addendum of the fix for bug 27786:
  applied the new function is_union() to the applicable places.
sql/sql_yacc.yy:
  addendum of the fix for bug 27786:
  applied the new function is_union() to the applicable places.

1 files changed, 1 insertions, 3 deletions

diff --git a/sql/sql_derived.cc b/sql/sql_derived.cc
index 89bd7958c86..ea7545fe5cb 100644
--- a/sql/sql_derived.cc
+++ b/sql/sql_derived.cc
@@ -236,9 +236,7 @@ bool mysql_derived_filling(THD *thd, LEX *lex, TABLE_LIST *orig_table_list)
     SELECT_LEX *first_select= unit->first_select();
     select_union *derived_result= orig_table_list->derived_result;
     SELECT_LEX *save_current_select= lex->current_select;
-    bool is_union= first_select->next_select() &&
-      first_select->next_select()->linkage == UNION_TYPE;
-    if (is_union)
+    if (unit->is_union())
     {
       // execute union without clean up
       res= unit->exec();