Do not prevent updates if untracked files are present

src/Composer/Downloader/GitDownloader.php

@@ -61,7 +61,7 @@ class GitDownloader extends VcsDownloader
      */
     protected function enforceCleanDirectory($path)
     {
-        $command = sprintf('cd %s && git status --porcelain', escapeshellarg($path));
+        $command = sprintf('cd %s && git status --porcelain --untracked-files=no', escapeshellarg($path));
         if (0 !== $this->process->execute($command, $output)) {
             throw new \RuntimeException('Failed to execute ' . $command . "\n\n" . $this->process->getErrorOutput());
         }

tests/Composer/Test/Downloader/GitDownloaderTest.php

@@ -140,7 +140,7 @@ class GitDownloaderTest extends \PHPUnit_Framework_TestCase
     public function testUpdate()
     {
         $expectedGitUpdateCommand = $this->getCmd("cd 'composerPath' && git remote set-url composer 'git://github.com/composer/composer' && git fetch composer && git fetch --tags composer && git checkout 'ref' && git reset --hard 'ref'");
-        $expectedGitResetCommand = $this->getCmd("cd 'composerPath' && git status --porcelain");
+        $expectedGitResetCommand = $this->getCmd("cd 'composerPath' && git status --porcelain --untracked-files=no");
 
         $packageMock = $this->getMock('Composer\Package\PackageInterface');
         $packageMock->expects($this->any())
@@ -173,7 +173,7 @@ class GitDownloaderTest extends \PHPUnit_Framework_TestCase
     public function testUpdateThrowsRuntimeExceptionIfGitCommandFails()
     {
         $expectedGitUpdateCommand = $this->getCmd("cd 'composerPath' && git remote set-url composer 'git://github.com/composer/composer' && git fetch composer && git fetch --tags composer && git checkout 'ref' && git reset --hard 'ref'");
-        $expectedGitResetCommand = $this->getCmd("cd 'composerPath' && git status --porcelain");
+        $expectedGitResetCommand = $this->getCmd("cd 'composerPath' && git status --porcelain --untracked-files=no");
 
         $packageMock = $this->getMock('Composer\Package\PackageInterface');
         $packageMock->expects($this->any())
@@ -202,7 +202,7 @@ class GitDownloaderTest extends \PHPUnit_Framework_TestCase
 
     public function testRemove()
     {
-        $expectedGitResetCommand = $this->getCmd("cd 'composerPath' && git status --porcelain");
+        $expectedGitResetCommand = $this->getCmd("cd 'composerPath' && git status --porcelain --untracked-files=no");
 
         $packageMock = $this->getMock('Composer\Package\PackageInterface');
         $processExecutor = $this->getMock('Composer\Util\ProcessExecutor');