From 37cdb0fbf3d9439829678614443834b2622d82db Mon Sep 17 00:00:00 2001
From: "svoj@may.pils.ru" <>
Date: Mon, 19 Jun 2006 14:05:14 +0500
Subject: [PATCH] BUG#18036 - update of table joined to self reports table as
 crashed Certain updates of table joined to self results in unexpected
 behavior.

The problem was that record cache was mistakenly enabled for
self-joined table updates. Normally record cache must be disabled
for such updates.

Fixed wrong condition in code that determines whether to use
record cache for self-joined table updates.

Only MyISAM tables were affected.
---
 mysql-test/r/myisam.result | 8 ++++++++
 mysql-test/t/myisam.test   | 9 +++++++++
 sql/sql_update.cc          | 2 +-
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/mysql-test/r/myisam.result b/mysql-test/r/myisam.result
index 3b4519e5444..7aaf3c8f85a 100644
--- a/mysql-test/r/myisam.result
+++ b/mysql-test/r/myisam.result
@@ -748,3 +748,11 @@ select count(id1) from t1 where id2 = 10;
 count(id1)
 5
 drop table t1;
+CREATE TABLE t1(a CHAR(9), b VARCHAR(7)) ENGINE=MyISAM;
+INSERT INTO t1(a) VALUES('xxxxxxxxx'),('xxxxxxxxx');
+UPDATE t1 AS ta1,t1 AS ta2 SET ta1.b='aaaaaa',ta2.b='bbbbbb';
+SELECT * FROM t1;
+a	b
+xxxxxxxxx	bbbbbb
+xxxxxxxxx	bbbbbb
+DROP TABLE t1;
diff --git a/mysql-test/t/myisam.test b/mysql-test/t/myisam.test
index 7e4cc324b12..5f948973141 100644
--- a/mysql-test/t/myisam.test
+++ b/mysql-test/t/myisam.test
@@ -705,4 +705,13 @@ select count(*)   from t1 where id2 = 10;
 select count(id1) from t1 where id2 = 10;
 drop table t1;
 
+#
+# BUG#18036 - update of table joined to self reports table as crashed
+#
+CREATE TABLE t1(a CHAR(9), b VARCHAR(7)) ENGINE=MyISAM;
+INSERT INTO t1(a) VALUES('xxxxxxxxx'),('xxxxxxxxx');
+UPDATE t1 AS ta1,t1 AS ta2 SET ta1.b='aaaaaa',ta2.b='bbbbbb';
+SELECT * FROM t1;
+DROP TABLE t1;
+
 # End of 4.1 tests
diff --git a/sql/sql_update.cc b/sql/sql_update.cc
index 48a8cf93917..16423b39786 100644
--- a/sql/sql_update.cc
+++ b/sql/sql_update.cc
@@ -862,7 +862,7 @@ int multi_update::prepare(List<Item> &not_used_values,
   for (table_ref= all_tables;  table_ref; table_ref=table_ref->next)
   {
     TABLE *table=table_ref->table;
-    if (!(tables_to_update & table->map) && 
+    if ((tables_to_update & table->map) && 
 	mysql_lock_have_duplicate(thd, table, update_tables))
       table->no_cache= 1;			// Disable row cache
   }