Merge branch 'mysql-5.5' into mysql-5.6

Author: Ajo Robert

sql/item.h

@@ -1,7 +1,7 @@
 #ifndef ITEM_INCLUDED
 #define ITEM_INCLUDED
 
-/* Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
 
    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
@@ -2017,6 +2017,12 @@ class Item_name_const : public Item
     return value_item->result_type();
   }
 
+  virtual bool cache_const_expr_analyzer(uchar **arg)
+  {
+    // Item_name_const always wraps a literal, so there is no need to cache it.
+    return false;
+  }
+
   type_conversion_status save_in_field(Field *field, bool no_conversions)
   {
     return  value_item->save_in_field(field, no_conversions);