item.cc, item.h:

  Post fix for bug#23800.

sql/item.cc

@@ -5497,6 +5497,7 @@ bool Item_outer_ref::fix_fields(THD *thd, Item **reference)
   if (!outer_field->fixed &&
       (outer_field->fix_fields(thd, reference)))
     return TRUE;
+  table_name= outer_field->table_name;
   return Item_direct_ref::fix_fields(thd, reference);
 }
 

sql/item.h

@@ -1968,7 +1968,6 @@ public:
                           outer_field_arg->field_name),
     outer_field(outer_field_arg)
   {
-    table_name= my_strdup(outer_field_arg->table_name, MYF(MY_WME));
     ref= (Item**)&outer_field;
     set_properties();
     fixed= 0;