Doctrine_Export::dropForeignKey() doesn't format foreign key names

Doctrine_Export::createForeignKey() formats foreign key names, but Doctrine_Export::dropForeignKey() doesn't. It is a problem.

I tested following:

echo "<?php

class addForeignKey extends Doctrine_Migration_Base
{
public function up()

Unknown macro: { $this->createForeignKey('user', 'dotted.foreign.key', array( 'local' => 'category_id', 'foreign' => 'id', 'foreignTable' => 'category', )); }

}" > migrations/1_add_foreign_key.php

echo "<?php

class removeForeignKey extends Doctrine_Migration_Base
{
public function up()

Unknown macro: { $this->dropForeignKey('user', 'dotted.foreign.key'); }

}" > migrations/2_add_foreign_key.php

./doctrine migrate 1 # successful

./doctrine migrate 2 # failed

1 error(s) encountered during migration
=======================================
Error #1 - SQLSTATE[42000]: Syntax error or access violation: 1103 Incorrect table name 'dotted'. Failing Query: "ALTER TABLE user DROP FOREIGN KEY dotted.foreign"

I have a patch to fix this problem.