Merge remote-tracking branch 'mysql/5.5' into 5.5

1 files changed, 15 insertions, 3 deletions

diff --git a/sql/sql_union.cc b/sql/sql_union.cc
index 95ce1c9b940..2d816e0309d 100644
--- a/sql/sql_union.cc
+++ b/sql/sql_union.cc
@@ -1,5 +1,5 @@
-/* Copyright (c) 2000, 2014, Oracle and/or its affiliates.
-   Copyright (c) 2010, 2014, SkySQL Ab.
+/* Copyright (c) 2000, 2017, Oracle and/or its affiliates.
+   Copyright (c) 2010, 2017, Corporation
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -362,6 +362,19 @@ bool st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
       Item *item_tmp;
       while ((item_tmp= it++))
       {
+        /*
+          If the outer query has a GROUP BY clause, an outer reference to this
+          query block may have been wrapped in a Item_outer_ref, which has not
+          been fixed yet. An Item_type_holder must be created based on a fixed
+          Item, so use the inner Item instead.
+        */
+        DBUG_ASSERT(item_tmp->fixed ||
+                    (item_tmp->type() == Item::REF_ITEM &&
+                     ((Item_ref *)(item_tmp))->ref_type() ==
+                     Item_ref::OUTER_REF));
+        if (!item_tmp->fixed)
+          item_tmp= item_tmp->real_item();
+
 	/* Error's in 'new' will be detected after loop */
 	types.push_back(new Item_type_holder(thd_arg, item_tmp));
       }
@@ -1070,4 +1083,3 @@ void st_select_lex_unit::set_unique_exclude()
     }
   }
 }
-