Merge naruto.:C:/cpp/bug20789/my50-bug20789

into  naruto.:C:/cpp/mysql-5.1-maint


storage/myisam/mi_locking.c:
  Auto merged

mysql-test/r/windows.result

@@ -6,3 +6,31 @@ use prn;
 ERROR 42000: Unknown database 'prn'
 create table nu (a int);
 drop table nu;
+CREATE TABLE `t1` (
+`TIM` datetime NOT NULL,
+`VAL` double default NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1;
+CREATE TABLE `t2` (
+`TIM` datetime NOT NULL,
+`VAL` double default NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1;
+CREATE TABLE `mt` (
+`TIM` datetime NOT NULL,
+`VAL` double default NULL
+) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=LAST
+UNION=(`t1`,`t2`);
+INSERT INTO mt VALUES ('2006-01-01',0);
+ALTER TABLE `t2` RENAME TO `t`;
+INSERT INTO mt VALUES ('2006-01-01',0);
+ERROR HY000: Can't lock file (errno: 155)
+select * from mt;
+ERROR HY000: Can't lock file (errno: 155)
+FLUSH TABLES;
+select * from mt;
+ERROR HY000: Can't find file: 'mt' (errno: 2)
+ALTER TABLE `t` RENAME TO `t2`;
+INSERT INTO mt VALUES ('2006-01-01',0);
+select * from mt;
+TIM	VAL
+2006-01-01 00:00:00	0
+2006-01-01 00:00:00	0

mysql-test/t/windows.test

@@ -18,3 +18,42 @@ create table nu (a int);
 drop table nu;
 
 # End of 4.1 tests
+
+#
+# Bug #20789: Merge Subtable Rename Causes Crash
+#
+CREATE TABLE `t1` (
+  `TIM` datetime NOT NULL,
+  `VAL` double default NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1;
+CREATE TABLE `t2` (
+  `TIM` datetime NOT NULL,
+  `VAL` double default NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1;
+CREATE TABLE `mt` (
+  `TIM` datetime NOT NULL,
+  `VAL` double default NULL
+) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=LAST
+UNION=(`t1`,`t2`);
+
+# insert into the merge table and thus open it.
+INSERT INTO mt VALUES ('2006-01-01',0);
+
+# Alter one of the tables that are part of the merge table
+ALTER TABLE `t2` RENAME TO `t`;
+
+# Insert into the merge table that has just been altered
+--error 1015
+INSERT INTO mt VALUES ('2006-01-01',0); 
+--error 1015
+select * from mt;
+
+FLUSH TABLES;
+--error 1017
+select * from mt;
+
+# Alter one of the tables that are part of the merge table
+ALTER TABLE `t` RENAME TO `t2`;
+INSERT INTO mt VALUES ('2006-01-01',0);
+select * from mt; 
+

storage/myisam/mi_locking.c

@@ -236,7 +236,18 @@ int mi_lock_database(MI_INFO *info, int lock_type)
     default:
       break;				/* Impossible */
     }
+  } 
+#ifdef __WIN__
+  else
+  {
+    /*
+      The file has been closed and kfile is -1.
+      See mi_extra.c about implementation of
+      HA_EXTRA_PREPARE_FOR_DELETE.
+    */
+    error=HA_ERR_NO_SUCH_TABLE;
   }
+#endif
   pthread_mutex_unlock(&share->intern_lock);
 #if defined(FULL_LOG) || defined(_lint)
   lock_type|=(int) (flag << 8);		/* Set bit to set if real lock */