From 5b8c42d91d3d709ffa4fca27f4199e52f72ca38e Mon Sep 17 00:00:00 2001
From: Igor Babaev <igor@askmonty.org>
Date: Thu, 8 Apr 2010 13:55:17 -0700
Subject: [PATCH] Fixed a problem of merge from mysql-5.1 baseline.

---
 sql/sql_select.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index c326b2770a9..e3b34126828 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -2335,7 +2335,13 @@ JOIN::destroy()
 	tab->cleanup();
     }
     tmp_join->tmp_join= 0;
+    /*
+      We need to clean up tmp_table_param for reusable JOINs (having non-zero
+      and different from self tmp_join) because it's not being cleaned up
+      anywhere else (as we need to keep the join is reusable).
+    */
     tmp_table_param.cleanup();
+    tmp_join->tmp_table_param.copy_field= 0;
     DBUG_RETURN(tmp_join->destroy());
   }
   cond_equal= 0;