bk commit into 5.1 tree (mskold:1.2198)

[Martin Skold]

Below is the list of changes that have just been committed into a local
5.1 repository of marty. When marty does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
For information on how to access the public repository
see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet
  1.2198 06/06/14 13:37:43 mskold@stripped +1 -0
  Merge mskold@stripped:/home/bk/mysql-5.1
  into  mysql.com:/home/marty/MySQL/mysql-5.1

  sql/sql_table.cc
    1.346 06/06/14 13:37:34 mskold@stripped +0 -0
    Auto merged

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	mskold
# Host:	linux.site
# Root:	/home/marty/MySQL/mysql-5.1/RESYNC

--- 1.345/sql/sql_table.cc	2006-06-14 12:23:02 +02:00
+++ 1.346/sql/sql_table.cc	2006-06-14 13:37:34 +02:00
@@ -4709,6 +4709,14 @@ static uint compare_tables(TABLE *table,
     At the moment we can't handle altering temporary tables without a copy.
     We also test if OPTIMIZE TABLE was given and was mapped to alter table.
     In that case we always do full copy.
+
+    There was a bug prior to mysql-4.0.25. Number of null fields was
+    calculated incorrectly. As a result frm and data files gets out of
+    sync after fast alter table. There is no way to determine by which
+    mysql version (in 4.0 and 4.1 branches) table was created, thus we
+    disable fast alter table for all tables created by mysql versions
+    prior to 5.0 branch.
+    See BUG#6236.
   */
   if (table->s->fields != create_list->elements ||
       table->s->db_type != create_info->db_type ||
@@ -4718,6 +4726,7 @@ static uint compare_tables(TABLE *table,
       create_info->used_fields & HA_CREATE_USED_DEFAULT_CHARSET ||
       (alter_info->flags & (ALTER_RECREATE | ALTER_FOREIGN_KEY)) ||
       order_num ||
+      !table->s->mysql_version ||
       (table->s->frm_version < FRM_VER_TRUE_VARCHAR && varchar))
     DBUG_RETURN(ALTER_TABLE_DATA_CHANGED);