HgDriver does not identify bitbucket mercurial repos correctly

src/Composer/Repository/Vcs/HgDriver.php

@@ -195,7 +195,7 @@ class HgDriver extends VcsDriver
      */
     public static function supports(IOInterface $io, Config $config, $url, $deep = false)
     {
-        if (preg_match('#(^(?:https?|ssh)://(?:[^@]@)?bitbucket.org|https://(?:.*?)\.kilnhg.com)#i', $url)) {
+        if (preg_match('#(^(?:https?|ssh)://(?:[^@]+@)?bitbucket.org|https://(?:.*?)\.kilnhg.com)#i', $url)) {
             return true;
         }
 

tests/Composer/Test/Repository/Vcs/HgDriverTest.php

@@ -0,0 +1,63 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Test\Repository\Vcs;
+
+use Composer\Repository\Vcs\HgDriver;
+use Composer\TestCase;
+use Composer\Util\Filesystem;
+use Composer\Config;
+
+class HgDriverTest extends TestCase
+{
+
+    /** @type \Composer\IO\IOInterface|\PHPUnit_Framework_MockObject_MockObject */
+    private $io;
+    /** @type \Composer\Config */
+    private $config;
+    /** @type string */
+    private $home;
+
+    public function setUp()
+    {
+        $this->io = $this->getMock('Composer\IO\IOInterface');
+        $this->home = $this->getUniqueTmpDirectory();
+        $this->config = new Config();
+        $this->config->merge(array(
+            'config' => array(
+                'home' => $this->home,
+            ),
+        ));
+    }
+
+    public function tearDown()
+    {
+        $fs = new Filesystem;
+        $fs->removeDirectory($this->home);
+    }
+
+    public function testSupports()
+    {
+        $this->assertTrue(
+            HgDriver::supports($this->io, $this->config, 'ssh://bitbucket.org/user/repo')
+        );
+
+        $this->assertTrue(
+            HgDriver::supports($this->io, $this->config, 'ssh://hg@bitbucket.org/user/repo')
+        );
+
+        $this->assertTrue(
+            HgDriver::supports($this->io, $this->config, 'ssh://user@bitbucket.org/user/repo')
+        );
+    }
+
+}