Upgrade from 4.4 to 4.5.1 creates incorrect columns in menu table when using PostgreSQL

I just upgraded my installation from 4.4 to 4.5.1 and got these errors when trying to administer the image module:

pg_query(): query failed: ERROR: invalid input syntax for integer

They were all for the menu table. On investigation, i found this in database/updates.inc:

if ($GLOBALS['db_type'] == 'mysql') {
$ret[] = update_sql("ALTER TABLE {menu} ADD description varchar(255) DEFAULT '' NOT NULL");
}
else {
$ret[] = update_sql("ALTER TABLE {menu} ADD description smallint");
$ret[] = update_sql("ALTER TABLE {menu} ALTER COLUMN description SET DEFAULT '0'");
$ret[] = update_sql("UPDATE {menu} SET description = '0'");
$ret[] = update_sql("ALTER TABLE {menu} ALTER COLUMN description SET NOT NULL");
}

WTH??? How is a smallint on other databases equivalent to varchar on mysql? Attached is a patch to fix the updates.inc file.