From 067f83e642f472ccae31b593fead20d7588f681a Mon Sep 17 00:00:00 2001
From: Tor Didriksen <tor.didriksen@oracle.com>
Date: Wed, 22 Feb 2012 11:17:50 +0100
Subject: [PATCH] Bug#13519724 63793: CRASH IN DTCOLLATION::SET(DTCOLLATION
 &SET)

Backport of fix for:
Bug#53236 Segfault in DTCollation::set(DTCollation&)
---
 mysql-test/r/cast.result |  9 +++++++++
 mysql-test/t/cast.test   | 12 ++++++++++++
 sql/sql_select.cc        |  4 ++--
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/mysql-test/r/cast.result b/mysql-test/r/cast.result
index 44d57055e7f..d7a7503707b 100644
--- a/mysql-test/r/cast.result
+++ b/mysql-test/r/cast.result
@@ -468,4 +468,13 @@ NULL
 Warnings:
 Warning	1301	Result of cast_as_char() was larger than max_allowed_packet (2048) - truncated
 SET @@GLOBAL.max_allowed_packet=default;
+#
+# Bug#13519724 63793: CRASH IN DTCOLLATION::SET(DTCOLLATION &SET)
+#
+CREATE TABLE t1 (a VARCHAR(50));
+SELECT a FROM t1 
+WHERE CAST(a as BINARY)=x'62736D697468' 
+AND CAST(a AS BINARY)=x'65736D697468';
+a
+DROP TABLE t1;
 End of 5.1 tests
diff --git a/mysql-test/t/cast.test b/mysql-test/t/cast.test
index 426d7c7fdf2..4474736200c 100644
--- a/mysql-test/t/cast.test
+++ b/mysql-test/t/cast.test
@@ -297,4 +297,16 @@ connection default;
 disconnect newconn;
 SET @@GLOBAL.max_allowed_packet=default;
 
+--echo #
+--echo # Bug#13519724 63793: CRASH IN DTCOLLATION::SET(DTCOLLATION &SET)
+--echo #
+
+CREATE TABLE t1 (a VARCHAR(50));
+
+SELECT a FROM t1 
+WHERE CAST(a as BINARY)=x'62736D697468' 
+  AND CAST(a AS BINARY)=x'65736D697468';
+
+DROP TABLE t1;
+
 --echo End of 5.1 tests
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 5f1efabfc97..0d8dc740431 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -8546,10 +8546,10 @@ change_cond_ref_to_const(THD *thd, I_List<COND_CMP> *save_list,
        left_item->collation.collation == value->collation.collation))
   {
     Item *tmp=value->clone_item();
-    tmp->collation.set(right_item->collation);
     
     if (tmp)
     {
+      tmp->collation.set(right_item->collation);
       thd->change_item_tree(args + 1, tmp);
       func->update_used_tables();
       if ((functype == Item_func::EQ_FUNC || functype == Item_func::EQUAL_FUNC)
@@ -8570,10 +8570,10 @@ change_cond_ref_to_const(THD *thd, I_List<COND_CMP> *save_list,
             right_item->collation.collation == value->collation.collation))
   {
     Item *tmp= value->clone_item();
-    tmp->collation.set(left_item->collation);
     
     if (tmp)
     {
+      tmp->collation.set(left_item->collation);
       thd->change_item_tree(args, tmp);
       value= tmp;
       func->update_used_tables();