Merge may.pils.ru:/home/svoj/devel/mysql/BUG18036/mysql-5.0

into  may.pils.ru:/home/svoj/devel/mysql/BUG18036/mysql-5.1

mysql-test/r/myisam.result

@@ -747,6 +747,14 @@ 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;
 set storage_engine=MyISAM;
 drop table if exists t1,t2,t3;
 --- Testing varchar ---

mysql-test/t/myisam.test

@@ -697,6 +697,15 @@ 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
 
 #
@@ -869,4 +878,3 @@ drop table t1;
 create table t1 (a int not null, key key_block_size=1024 (a));
 --error 1064
 create table t1 (a int not null, key `a` key_block_size=1024 (a));
-

sql/sql_update.cc

@@ -985,7 +985,12 @@ reopen_tables:
       }
     }
   }
-
+  /*
+    Set exclude_from_table_unique_test value back to FALSE. It is needed for
+    further check in multi_update::prepare whether to use record cache.
+  */
+  lex->select_lex.exclude_from_table_unique_test= FALSE;
+ 
   if (thd->fill_derived_tables() &&
       mysql_handle_derived(lex, &mysql_derived_filling))
     DBUG_RETURN(TRUE);
@@ -1164,7 +1169,7 @@ int multi_update::prepare(List<Item> &not_used_values,
   for (table_ref= leaves;  table_ref; table_ref= table_ref->next_leaf)
   {
     TABLE *table=table_ref->table;
-    if (!(tables_to_update & table->map) &&
+    if ((tables_to_update & table->map) &&
         unique_table(thd, table_ref, update_tables))
       table->no_cache= 1;			// Disable row cache
   }