--- mysql-5.0.bk-orig/sql/item_sum.cc	Sat Apr  7 12:23:32 2007
+++ mysql-5.0.bk/sql/item_sum.cc	Thu Apr 12 22:42:02 2007
@@ -274,6 +274,19 @@
          sl && sl != aggr_sel && sl->master_unit()->item;
          sl= sl->master_unit()->outer_select() )
       sl->master_unit()->item->with_sum_func= 1;
+
+    /* Add note for explain extended */
+    if (thd->lex->describe & DESCRIBE_EXTENDED)
+    {
+      String printed_name;
+      (*ref)->full_name_or_print(&printed_name);
+      push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
+                          ER_WARN_FIELD_RESOLVED,
+                          ER(ER_WARN_FIELD_RESOLVED),
+                          printed_name.ptr(), "", "", "", "",
+                          thd->lex->current_select->select_number,
+                          aggr_sel->select_number);
+    }
   }
   thd->lex->current_select->mark_as_dependent(aggr_sel);
   return FALSE;
--- mysql-5.0.bk-orig/sql/item.h	Sat Apr  7 12:23:32 2007
+++ mysql-5.0.bk/sql/item.h	Thu Apr 12 22:43:33 2007
@@ -617,6 +617,13 @@
   /* This is also used to create fields in CREATE ... SELECT: */
   virtual Field *tmp_table_field(TABLE *t_arg) { return 0; }
   virtual const char *full_name() const { return name ? name : "???"; }
+  void full_name_or_print(String *result)
+  {
+    if (name)
+      result->set(name, (uint32) name_length, &my_charset_bin);
+    else
+      print(result);
+  }
 
   /*
     *result* family of methods is analog of *val* family (see above) but