bk commit into 5.0 tree (svoj:1.2531) BUG#29957

[Sergey Vojtovich]

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ChangeSet@stripped, 2007-07-26 15:24:09+05:00, svoj@stripped +3 -0
  BUG#29957 - alter_table.test fails
  
  INSERT/DELETE/UPDATE followed by ALTER TABLE within LOCK TABLES
  may cause table corruption on Windows.
  
  That happens because ALTER TABLE writes outdated shared state
  info into index file.
  
  Fixed by updating shared state info prior to actually writing it
  to disk.
  
  Affects MyISAM tables on Windows only.

  myisam/mi_extra.c@stripped, 2007-07-26 15:24:07+05:00, svoj@stripped +1 -0
    On windows when mi_extra(HA_EXTRA_PREPARE_FOR_DELETE) is called,
    we release external lock and close index file. If we're in LOCK
    TABLES, MyISAM state info doesn't get updated until UNLOCK TABLES.
    
    That means when we release external lock and we're in LOCK TABLES,
    we may write outdated state info.
    
    Fixed by updating state info prior to releasing external lock.

  mysql-test/r/alter_table.result@stripped, 2007-07-26 15:24:07+05:00, svoj@stripped +12 -0
    A test case for BUG#29957.

  mysql-test/t/alter_table.test@stripped, 2007-07-26 15:24:07+05:00, svoj@stripped +12 -0
    A test case for BUG#29957.

diff -Nrup a/myisam/mi_extra.c b/myisam/mi_extra.c
--- a/myisam/mi_extra.c	2006-12-31 00:02:04 +04:00
+++ b/myisam/mi_extra.c	2007-07-26 15:24:07 +05:00
@@ -298,6 +298,7 @@ int mi_extra(MI_INFO *info, enum ha_extr
     if (info->lock_type != F_UNLCK && ! info->was_locked)
     {
       info->was_locked=info->lock_type;
+      mi_update_status((void*) info);
       if (mi_lock_database(info,F_UNLCK))
 	error=my_errno;
       info->lock_type = F_UNLCK;
diff -Nrup a/mysql-test/r/alter_table.result b/mysql-test/r/alter_table.result
--- a/mysql-test/r/alter_table.result	2007-05-22 01:20:29 +05:00
+++ b/mysql-test/r/alter_table.result	2007-07-26 15:24:07 +05:00
@@ -903,3 +903,15 @@ f1	f2	f21	f4	f41
 1	2000-01-01 00:00:00	2000-01-01	2002-02-02 00:00:00	2002-02-02
 drop table t1;
 set sql_mode= @orig_sql_mode;
+create table t1 (c char(10) default "Two");
+lock table t1 write;
+insert into t1 values ();
+alter table t1 modify c char(10) default "Three";
+unlock tables;
+select * from t1;
+c
+Two
+check table t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+drop table t1;
diff -Nrup a/mysql-test/t/alter_table.test b/mysql-test/t/alter_table.test
--- a/mysql-test/t/alter_table.test	2007-05-22 01:18:34 +05:00
+++ b/mysql-test/t/alter_table.test	2007-07-26 15:24:07 +05:00
@@ -684,3 +684,15 @@ alter table t1 add column f4 datetime no
 select * from t1;
 drop table t1;
 set sql_mode= @orig_sql_mode;
+
+#
+# BUG#29957 - alter_table.test fails
+#
+create table t1 (c char(10) default "Two");
+lock table t1 write;
+insert into t1 values ();
+alter table t1 modify c char(10) default "Three";
+unlock tables;
+select * from t1;
+check table t1;
+drop table t1;