diff --git a/.travis.yml b/.travis.yml
index a06922904..2460a200c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,9 +30,11 @@ matrix:
       env:
         - deps=high
     - php: nightly
+    - php: 7.4snapshot
   fast_finish: true
   allow_failures:
     - php: nightly
+    - php: 7.4snapshot
 
 before_install:
   # disable xdebug if available
@@ -62,7 +64,7 @@ script:
   - ls -d tests/Composer/Test/* | grep -v TestCase.php | parallel --gnu --keep-order 'echo "Running {} tests"; ./vendor/bin/phpunit -c tests/complete.phpunit.xml --colors=always {} || (echo -e "\e[41mFAILED\e[0m {}" && exit 1);'
   # Run PHPStan
   - if [[ $PHPSTAN == "1" ]]; then
-      composer require --dev phpstan/phpstan-shim:^0.11 --ignore-platform-reqs &&
+      bin/composer require --dev phpstan/phpstan-shim:^0.11 --ignore-platform-reqs &&
       vendor/bin/phpstan.phar analyse src tests --configuration=phpstan/config.neon --autoload-file=phpstan/autoload.php;
     fi
 
diff --git a/doc/03-cli.md b/doc/03-cli.md
index c04522733..08beb716b 100644
--- a/doc/03-cli.md
+++ b/doc/03-cli.md
@@ -259,6 +259,10 @@ match the platform requirements of the installed packages. This can be used
 to verify that a production server has all the extensions needed to run a
 project after installing it for example.
 
+Unlike update/install, this command will ignore config.platform settings and
+check the real platform packages so you can be certain you have the required
+platform dependencies.
+
 ## global
 
 The global command allows you to run other commands like `install`, `remove`, `require`
diff --git a/doc/articles/handling-private-packages-with-satis.md b/doc/articles/handling-private-packages-with-satis.md
index cdf31f6e4..3ef604fe7 100644
--- a/doc/articles/handling-private-packages-with-satis.md
+++ b/doc/articles/handling-private-packages-with-satis.md
@@ -112,6 +112,19 @@ Note that this will still need to pull and scan all of your VCS repositories
 because any VCS repository might contain (on any branch) one of the selected
 packages.
 
+If you want to scan only the selected package and not all VCS repositories you need
+to declare a *name* for all your package (this only work on VCS repositories type) :
+
+```json
+{
+  "repositories": [
+    { "name": "company/privaterepo", "type": "vcs", "url": "https://github.com/mycompany/privaterepo" },
+    { "name": "private/repo", "type": "vcs", "url": "http://svn.example.org/private/repo" },
+    { "name": "mycompany/privaterepo2", "type": "vcs", "url": "https://github.com/mycompany/privaterepo2" }
+  ]
+}
+```
+
 If you want to scan only a single repository and update all packages found in
 it, pass the VCS repository URL as an optional argument:
 
diff --git a/phpstan/config.neon b/phpstan/config.neon
index 9fd155963..0c5dc30b8 100644
--- a/phpstan/config.neon
+++ b/phpstan/config.neon
@@ -16,7 +16,6 @@ parameters:
         - '~^Anonymous function has an unused use \$io\.$~'
         - '~^Anonymous function has an unused use \$cache\.$~'
         - '~^Anonymous function has an unused use \$path\.$~'
-        - '~^Anonymous function has an unused use \$fileName\.$~'
 
         # ion cube is not installed
         - '~^Function ioncube_loader_\w+ not found\.$~'
diff --git a/src/Composer/Command/CheckPlatformReqsCommand.php b/src/Composer/Command/CheckPlatformReqsCommand.php
index de7f4b4d3..195a2c490 100644
--- a/src/Composer/Command/CheckPlatformReqsCommand.php
+++ b/src/Composer/Command/CheckPlatformReqsCommand.php
@@ -34,6 +34,8 @@ class CheckPlatformReqsCommand extends BaseCommand
                 <<<EOT
 Checks that your PHP and extensions versions match the platform requirements of the installed packages.
 
+Unlike update/install, this command will ignore config.platform settings and check the real platform packages so you can be certain you have the required platform dependencies.
+
 <info>php composer.phar check-platform-reqs</info>
 
 EOT
@@ -49,6 +51,10 @@ EOT
             $dependencies = $composer->getLocker()->getLockedRepository(!$input->getOption('no-dev'))->getPackages();
         } else {
             $dependencies = $composer->getRepositoryManager()->getLocalRepository()->getPackages();
+            // fallback to lockfile if installed repo is empty
+            if (!$dependencies) {
+                $dependencies = $composer->getLocker()->getLockedRepository(true)->getPackages();
+            }
             $requires += $composer->getPackage()->getDevRequires();
         }
         foreach ($requires as $require => $link) {
diff --git a/src/Composer/Command/DiagnoseCommand.php b/src/Composer/Command/DiagnoseCommand.php
index c2123e066..3bcc665dc 100644
--- a/src/Composer/Command/DiagnoseCommand.php
+++ b/src/Composer/Command/DiagnoseCommand.php
@@ -156,7 +156,7 @@ EOT
             $this->outputResult($this->checkVersion($config));
         }
 
-        $io->write(sprintf('Composer version: <comment>%s</comment>', Composer::VERSION));
+        $io->write(sprintf('Composer version: <comment>%s</comment>', Composer::getVersion()));
 
         $platformOverrides = $config->get('platform') ?: array();
         $platformRepo = new PlatformRepository(array(), $platformOverrides);
@@ -254,7 +254,7 @@ EOT
 
         $protocol = extension_loaded('openssl') ? 'https' : 'http';
         try {
-            $json = $this->httpDownloader->get($protocol . '://repo.packagist.org/packages.json')->parseJson();
+            $json = $this->httpDownloader->get($protocol . '://repo.packagist.org/packages.json')->decodeJson();
             $hash = reset($json['provider-includes']);
             $hash = $hash['sha256'];
             $path = str_replace('%hash%', $hash, key($json['provider-includes']));
@@ -375,7 +375,7 @@ EOT
         }
 
         $url = $domain === 'github.com' ? 'https://api.'.$domain.'/rate_limit' : 'https://'.$domain.'/api/rate_limit';
-        $data = $this->httpDownloader->get($url, array('retry-auth-failure' => false))->parseJson();
+        $data = $this->httpDownloader->get($url, array('retry-auth-failure' => false))->decodeJson();
 
         return $data['resources']['core'];
     }
diff --git a/src/Composer/Command/InitCommand.php b/src/Composer/Command/InitCommand.php
index ac4b26ec8..08f891014 100644
--- a/src/Composer/Command/InitCommand.php
+++ b/src/Composer/Command/InitCommand.php
@@ -168,13 +168,25 @@ EOT
         if ($repositories) {
             $config = Factory::createConfig($io);
             $repos = array(new PlatformRepository);
+            $createDefaultPackagistRepo = true;
             foreach ($repositories as $repo) {
-                $repos[] = RepositoryFactory::fromString($io, $config, $repo);
+                $repoConfig = RepositoryFactory::configFromString($io, $config, $repo);
+                if (
+                    (isset($repoConfig['packagist']) && $repoConfig === array('packagist' => false))
+                    || (isset($repoConfig['packagist.org']) && $repoConfig === array('packagist.org' => false))
+                ) {
+                    $createDefaultPackagistRepo = false;
+                    continue;
+                }
+                $repos[] = RepositoryFactory::createRepo($io, $config, $repoConfig);
+            }
+
+            if ($createDefaultPackagistRepo) {
+                $repos[] = RepositoryFactory::createRepo($io, $config, array(
+                    'type' => 'composer',
+                    'url' => 'https://repo.packagist.org',
+                ));
             }
-            $repos[] = RepositoryFactory::createRepo($io, $config, array(
-                'type' => 'composer',
-                'url' => 'https://repo.packagist.org',
-            ));
 
             $this->repos = new CompositeRepository($repos);
             unset($repos, $config, $repositories);
diff --git a/src/Composer/Command/RequireCommand.php b/src/Composer/Command/RequireCommand.php
index 8a06d46ad..876371635 100644
--- a/src/Composer/Command/RequireCommand.php
+++ b/src/Composer/Command/RequireCommand.php
@@ -26,6 +26,7 @@ use Composer\Plugin\PluginEvents;
 use Composer\Repository\CompositeRepository;
 use Composer\Repository\PlatformRepository;
 use Composer\IO\IOInterface;
+use Composer\Util\Silencer;
 
 /**
  * @author Jérémy Romey <jeremy@free-agent.fr>
@@ -103,11 +104,6 @@ EOT
 
             return 1;
         }
-        if (!is_writable($this->file)) {
-            $io->writeError('<error>'.$this->file.' is not writable.</error>');
-
-            return 1;
-        }
 
         if (filesize($this->file) === 0) {
             file_put_contents($this->file, "{\n}\n");
@@ -116,6 +112,14 @@ EOT
         $this->json = new JsonFile($this->file);
         $this->composerBackup = file_get_contents($this->json->getPath());
 
+        // check for writability by writing to the file as is_writable can not be trusted on network-mounts
+        // see https://github.com/composer/composer/issues/8231 and https://bugs.php.net/bug.php?id=68926
+        if (!is_writable($this->file) && !Silencer::call('file_put_contents', $this->file, $this->composerBackup)) {
+            $io->writeError('<error>'.$this->file.' is not writable.</error>');
+
+            return 1;
+        }
+
         $composer = $this->getComposer(true, $input->getOption('no-plugins'));
         $repos = $composer->getRepositoryManager()->getRepositories();
 
@@ -141,7 +145,12 @@ EOT
 
         // validate requirements format
         $versionParser = new VersionParser();
-        foreach ($requirements as $constraint) {
+        foreach ($requirements as $package => $constraint) {
+            if (strtolower($package) === $composer->getPackage()->getName()) {
+                $io->writeError(sprintf('<error>Root package \'%s\' cannot require itself in its composer.json</error>', $package));
+
+                return 1;
+            }
             $versionParser->parseConstraints($constraint);
         }
 
diff --git a/src/Composer/Console/Application.php b/src/Composer/Console/Application.php
index a91f96f0d..a9fb2e117 100644
--- a/src/Composer/Console/Application.php
+++ b/src/Composer/Console/Application.php
@@ -379,6 +379,9 @@ class Application extends BaseApplication
     public function resetComposer()
     {
         $this->composer = null;
+        if ($this->getIO() && method_exists($this->getIO(), 'resetAuthentications')) {
+            $this->getIO()->resetAuthentications();
+        }
     }
 
     /**
diff --git a/src/Composer/DependencyResolver/RuleSetGenerator.php b/src/Composer/DependencyResolver/RuleSetGenerator.php
index 0a63eaacb..64cb27b11 100644
--- a/src/Composer/DependencyResolver/RuleSetGenerator.php
+++ b/src/Composer/DependencyResolver/RuleSetGenerator.php
@@ -195,7 +195,7 @@ class RuleSetGenerator
         }
     }
 
-    protected function addConflictRules()
+    protected function addConflictRules($ignorePlatformReqs = false)
     {
         /** @var PackageInterface $package */
         foreach ($this->addedPackages as $package) {
@@ -204,6 +204,10 @@ class RuleSetGenerator
                     continue;
                 }
 
+                if ($ignorePlatformReqs && preg_match(PlatformRepository::PLATFORM_PACKAGE_REGEX, $link->getTarget())) {
+                    continue;
+                }
+
                 /** @var PackageInterface $possibleConflict */
                 foreach ($this->addedPackagesByNames[$link->getTarget()] as $possibleConflict) {
                     $conflictMatch = $this->pool->match($possibleConflict, $link->getTarget(), $link->getConstraint(), true);
@@ -305,7 +309,7 @@ class RuleSetGenerator
 
         $this->addRulesForRequest($request, $ignorePlatformReqs);
 
-        $this->addConflictRules();
+        $this->addConflictRules($ignorePlatformReqs);
 
         // Remove references to packages
         $this->addedPackages = $this->addedPackagesByNames = null;
diff --git a/src/Composer/Downloader/ArchiveDownloader.php b/src/Composer/Downloader/ArchiveDownloader.php
index 3c53a086e..be863f1d3 100644
--- a/src/Composer/Downloader/ArchiveDownloader.php
+++ b/src/Composer/Downloader/ArchiveDownloader.php
@@ -33,16 +33,16 @@ abstract class ArchiveDownloader extends FileDownloader
     public function install(PackageInterface $package, $path, $output = true)
     {
         if ($output) {
-            $this->io->writeError("  - Installing <info>" . $package->getName() . "</info> (<comment>" . $package->getFullPrettyVersion() . "</comment>)");
+            $this->io->writeError("  - Installing <info>" . $package->getName() . "</info> (<comment>" . $package->getFullPrettyVersion() . "</comment>): Extracting archive");
+        } else {
+            $this->io->writeError('Extracting archive', false);
         }
 
+        $this->filesystem->emptyDirectory($path);
+
         $temporaryDir = $this->config->get('vendor-dir').'/composer/'.substr(md5(uniqid('', true)), 0, 8);
         $fileName = $this->getFileName($package, $path);
 
-        if ($output) {
-            $this->io->writeError('    Extracting archive', true, IOInterface::VERBOSE);
-        }
-
         try {
             $this->filesystem->ensureDirectoryExists($temporaryDir);
             try {
diff --git a/src/Composer/Downloader/DownloadManager.php b/src/Composer/Downloader/DownloadManager.php
index a23c167b5..794998bb2 100644
--- a/src/Composer/Downloader/DownloadManager.php
+++ b/src/Composer/Downloader/DownloadManager.php
@@ -165,9 +165,9 @@ class DownloadManager
     /**
      * Downloads package into target dir.
      *
-     * @param PackageInterface $package      package instance
-     * @param string           $targetDir    target dir
-     * @param PackageInterface $prevPackage  previous package instance in case of updates
+     * @param PackageInterface      $package      package instance
+     * @param string                $targetDir    target dir
+     * @param PackageInterface|null $prevPackage  previous package instance in case of updates
      *
      * @return PromiseInterface
      * @throws \InvalidArgumentException if package have no urls to download from
@@ -182,7 +182,7 @@ class DownloadManager
         $io = $this->io;
         $self = $this;
 
-        $download = function ($retry = false) use (&$sources, $io, $package, $self, $targetDir, &$download) {
+        $download = function ($retry = false) use (&$sources, $io, $package, $self, $targetDir, &$download, $prevPackage) {
             $source = array_shift($sources);
             if ($retry) {
                 $io->writeError('    <warning>Now trying to download from ' . $source . '</warning>');
@@ -214,7 +214,7 @@ class DownloadManager
             };
 
             try {
-                $result = $downloader->download($package, $targetDir);
+                $result = $downloader->download($package, $targetDir, $prevPackage);
             } catch (\Exception $e) {
                 return $handleError($e);
             }
@@ -232,12 +232,31 @@ class DownloadManager
         return $download();
     }
 
+    /**
+     * Prepares an operation execution
+     *
+     * @param string                $type         one of install/update/uninstall
+     * @param PackageInterface      $package      package instance
+     * @param string                $targetDir    target dir
+     * @param PackageInterface|null $prevPackage  previous package instance in case of updates
+     *
+     * @return PromiseInterface|null
+     */
+    public function prepare($type, PackageInterface $package, $targetDir, PackageInterface $prevPackage = null)
+    {
+        $downloader = $this->getDownloaderForPackage($package);
+        if ($downloader) {
+            return $downloader->prepare($type, $package, $targetDir, $prevPackage);
+        }
+    }
+
     /**
      * Installs package into target dir.
      *
      * @param PackageInterface $package      package instance
      * @param string           $targetDir    target dir
      *
+     * @return PromiseInterface|null
      * @throws \InvalidArgumentException if package have no urls to download from
      * @throws \RuntimeException
      */
@@ -245,7 +264,7 @@ class DownloadManager
     {
         $downloader = $this->getDownloaderForPackage($package);
         if ($downloader) {
-            $downloader->install($package, $targetDir);
+            return $downloader->install($package, $targetDir);
         }
     }
 
@@ -256,6 +275,7 @@ class DownloadManager
      * @param PackageInterface $target    target package version
      * @param string           $targetDir target dir
      *
+     * @return PromiseInterface|null
      * @throws \InvalidArgumentException if initial package is not installed
      */
     public function update(PackageInterface $initial, PackageInterface $target, $targetDir)
@@ -270,17 +290,14 @@ class DownloadManager
 
         // if we have a downloader present before, but not after, the package became a metapackage and its files should be removed
         if (!$downloader) {
-            $initialDownloader->remove($initial, $targetDir);
-            return;
+            return $initialDownloader->remove($initial, $targetDir);
         }
 
         $initialType = $this->getDownloaderType($initialDownloader);
         $targetType = $this->getDownloaderType($downloader);
         if ($initialType === $targetType) {
             try {
-                $downloader->update($initial, $target, $targetDir);
-
-                return;
+                return $downloader->update($initial, $target, $targetDir);
             } catch (\RuntimeException $e) {
                 if (!$this->io->isInteractive()) {
                     throw $e;
@@ -294,8 +311,15 @@ class DownloadManager
 
         // if downloader type changed, or update failed and user asks for reinstall,
         // we wipe the dir and do a new install instead of updating it
-        $initialDownloader->remove($initial, $targetDir);
-        $this->install($target, $targetDir);
+        $promise = $initialDownloader->remove($initial, $targetDir);
+        if ($promise) {
+            $self = $this;
+            return $promise->then(function ($res) use ($self, $target, $targetDir) {
+                return $self->install($target, $targetDir);
+            });
+        }
+
+        return $this->install($target, $targetDir);
     }
 
     /**
@@ -303,12 +327,32 @@ class DownloadManager
      *
      * @param PackageInterface $package   package instance
      * @param string           $targetDir target dir
+     *
+     * @return PromiseInterface|null
      */
     public function remove(PackageInterface $package, $targetDir)
     {
         $downloader = $this->getDownloaderForPackage($package);
         if ($downloader) {
-            $downloader->remove($package, $targetDir);
+            return $downloader->remove($package, $targetDir);
+        }
+    }
+
+    /**
+     * Cleans up a failed operation
+     *
+     * @param string                $type         one of install/update/uninstall
+     * @param PackageInterface      $package      package instance
+     * @param string                $targetDir    target dir
+     * @param PackageInterface|null $prevPackage  previous package instance in case of updates
+     *
+     * @return PromiseInterface|null
+     */
+    public function cleanup($type, PackageInterface $package, $targetDir, PackageInterface $prevPackage = null)
+    {
+        $downloader = $this->getDownloaderForPackage($package);
+        if ($downloader) {
+            return $downloader->cleanup($type, $package, $targetDir, $prevPackage);
         }
     }
 
diff --git a/src/Composer/Downloader/DownloaderInterface.php b/src/Composer/Downloader/DownloaderInterface.php
index 2074b16da..01e7f95c8 100644
--- a/src/Composer/Downloader/DownloaderInterface.php
+++ b/src/Composer/Downloader/DownloaderInterface.php
@@ -31,14 +31,30 @@ interface DownloaderInterface
     public function getInstallationSource();
 
     /**
-     * This should do any network-related tasks to prepare for install/update
+     * This should do any network-related tasks to prepare for an upcoming install/update
      *
      * @return PromiseInterface|null
      */
-    public function download(PackageInterface $package, $path);
+    public function download(PackageInterface $package, $path, PackageInterface $prevPackage = null);
 
     /**
-     * Downloads specific package into specific folder.
+     * Do anything that needs to be done between all downloads have been completed and the actual operation is executed
+     *
+     * All packages get first downloaded, then all together prepared, then all together installed/updated/uninstalled. Therefore
+     * for error recovery it is important to avoid failing during install/update/uninstall as much as possible, and risky things or
+     * user prompts should happen in the prepare step rather. In case of failure, cleanup() will be called so that changes can
+     * be undone as much as possible.
+     *
+     * @param  string                $type        one of install/update/uninstall
+     * @param  PackageInterface      $package     package instance
+     * @param  string                $path        download path
+     * @param  PackageInterface      $prevPackage previous package instance in case of an update
+     * @return PromiseInterface|null
+     */
+    public function prepare($type, PackageInterface $package, $path, PackageInterface $prevPackage = null);
+
+    /**
+     * Installs specific package into specific folder.
      *
      * @param PackageInterface $package package instance
      * @param string           $path    download path
@@ -61,4 +77,19 @@ interface DownloaderInterface
      * @param string           $path    download path
      */
     public function remove(PackageInterface $package, $path);
+
+    /**
+     * Do anything to cleanup changes applied in the prepare or install/update/uninstall steps
+     *
+     * Note that cleanup will be called for all packages regardless if they failed an operation or not, to give
+     * all installers a change to cleanup things they did previously, so you need to keep track of changes
+     * applied in the installer/downloader themselves.
+     *
+     * @param  string                $type        one of install/update/uninstall
+     * @param  PackageInterface      $package     package instance
+     * @param  string                $path        download path
+     * @param  PackageInterface      $prevPackage previous package instance in case of an update
+     * @return PromiseInterface|null
+     */
+    public function cleanup($type, PackageInterface $package, $path, PackageInterface $prevPackage = null);
 }
diff --git a/src/Composer/Downloader/FileDownloader.php b/src/Composer/Downloader/FileDownloader.php
index 2c66c23a3..20d21804d 100644
--- a/src/Composer/Downloader/FileDownloader.php
+++ b/src/Composer/Downloader/FileDownloader.php
@@ -84,7 +84,7 @@ class FileDownloader implements DownloaderInterface, ChangeReportInterface
     /**
      * {@inheritDoc}
      */
-    public function download(PackageInterface $package, $path, $output = true)
+    public function download(PackageInterface $package, $path, PackageInterface $prevPackage = null, $output = true)
     {
         if (!$package->getDistUrl()) {
             throw new \InvalidArgumentException('The given package is missing url information');
@@ -101,7 +101,7 @@ class FileDownloader implements DownloaderInterface, ChangeReportInterface
             );
         }
 
-        $this->filesystem->emptyDirectory($path);
+        $this->filesystem->ensureDirectoryExists($path);
         $fileName = $this->getFileName($package, $path);
 
         $io = $this->io;
@@ -176,7 +176,9 @@ class FileDownloader implements DownloaderInterface, ChangeReportInterface
 
         $reject = function ($e) use ($io, &$urls, $download, $fileName, $path, $package, &$retries, $filesystem, $self) {
             // clean up
-            $filesystem->removeDirectory($path);
+            if (file_exists($fileName)) {
+                $filesystem->unlink($fileName);
+            }
             $self->clearLastCacheWrite($package);
 
             if ($e instanceof TransportException) {
@@ -220,6 +222,20 @@ class FileDownloader implements DownloaderInterface, ChangeReportInterface
         return $download();
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    public function prepare($type, PackageInterface $package, $path, PackageInterface $prevPackage = null)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function cleanup($type, PackageInterface $package, $path, PackageInterface $prevPackage = null)
+    {
+    }
+
     /**
      * {@inheritDoc}
      */
@@ -229,6 +245,7 @@ class FileDownloader implements DownloaderInterface, ChangeReportInterface
             $this->io->writeError("  - Installing <info>" . $package->getName() . "</info> (<comment>" . $package->getFullPrettyVersion() . "</comment>)");
         }
 
+        $this->filesystem->emptyDirectory($path);
         $this->filesystem->ensureDirectoryExists($path);
         $this->filesystem->rename($this->getFileName($package, $path), $path . pathinfo(parse_url($package->getDistUrl(), PHP_URL_PATH), PATHINFO_BASENAME));
     }
@@ -333,7 +350,7 @@ class FileDownloader implements DownloaderInterface, ChangeReportInterface
         $e = null;
 
         try {
-            $res = $this->download($package, $targetDir.'_compare', false);
+            $res = $this->download($package, $targetDir.'_compare', null, false);
             $this->httpDownloader->wait();
             $res = $this->install($package, $targetDir.'_compare', false);
 
diff --git a/src/Composer/Downloader/FossilDownloader.php b/src/Composer/Downloader/FossilDownloader.php
index a814f89b7..be7c987b3 100644
--- a/src/Composer/Downloader/FossilDownloader.php
+++ b/src/Composer/Downloader/FossilDownloader.php
@@ -23,7 +23,15 @@ class FossilDownloader extends VcsDownloader
     /**
      * {@inheritDoc}
      */
-    public function doInstall(PackageInterface $package, $path, $url)
+    protected function doDownload(PackageInterface $package, $path, $url, PackageInterface $prevPackage = null)
+    {
+
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    protected function doInstall(PackageInterface $package, $path, $url)
     {
         // Ensure we are allowed to use this URL by config
         $this->config->prohibitUrlByConfig($url, $this->io);
@@ -49,7 +57,7 @@ class FossilDownloader extends VcsDownloader
     /**
      * {@inheritDoc}
      */
-    public function doUpdate(PackageInterface $initial, PackageInterface $target, $path, $url)
+    protected function doUpdate(PackageInterface $initial, PackageInterface $target, $path, $url)
     {
         // Ensure we are allowed to use this URL by config
         $this->config->prohibitUrlByConfig($url, $this->io);
diff --git a/src/Composer/Downloader/GitDownloader.php b/src/Composer/Downloader/GitDownloader.php
index f698981fe..3d3d947f4 100644
--- a/src/Composer/Downloader/GitDownloader.php
+++ b/src/Composer/Downloader/GitDownloader.php
@@ -29,6 +29,7 @@ class GitDownloader extends VcsDownloader implements DvcsDownloaderInterface
     private $hasStashedChanges = false;
     private $hasDiscardedChanges = false;
     private $gitUtil;
+    private $cachedPackages = array();
 
     public function __construct(IOInterface $io, Config $config, ProcessExecutor $process = null, Filesystem $fs = null)
     {
@@ -39,7 +40,28 @@ class GitDownloader extends VcsDownloader implements DvcsDownloaderInterface
     /**
      * {@inheritDoc}
      */
-    public function doInstall(PackageInterface $package, $path, $url)
+    protected function doDownload(PackageInterface $package, $path, $url, PackageInterface $prevPackage = null)
+    {
+        GitUtil::cleanEnv();
+
+        $cachePath = $this->config->get('cache-vcs-dir').'/'.preg_replace('{[^a-z0-9.]}i', '-', $url).'/';
+        $gitVersion = $this->gitUtil->getVersion();
+
+        // --dissociate option is only available since git 2.3.0-rc0
+        if ($gitVersion && version_compare($gitVersion, '2.3.0-rc0', '>=') && Cache::isUsable($cachePath)) {
+            $this->io->writeError("  - Syncing <info>" . $package->getName() . "</info> (<comment>" . $package->getFullPrettyVersion() . "</comment>) into cache");
+            $this->io->writeError(sprintf('    Cloning to cache at %s', ProcessExecutor::escape($cachePath)), true, IOInterface::DEBUG);
+            $ref = $package->getSourceReference();
+            if ($this->gitUtil->fetchRefOrSyncMirror($url, $cachePath, $ref) && is_dir($cachePath)) {
+                $this->cachedPackages[$package->getId()][$ref] = true;
+            }
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    protected function doInstall(PackageInterface $package, $path, $url)
     {
         GitUtil::cleanEnv();
         $path = $this->normalizePath($path);
@@ -47,26 +69,20 @@ class GitDownloader extends VcsDownloader implements DvcsDownloaderInterface
         $ref = $package->getSourceReference();
         $flag = Platform::isWindows() ? '/D ' : '';
 
-        // --dissociate option is only available since git 2.3.0-rc0
-        $gitVersion = $this->gitUtil->getVersion();
-        $msg = "Cloning ".$this->getShortHash($ref);
-
-        $command = 'git clone --no-checkout %url% %path% && cd '.$flag.'%path% && git remote add composer %url% && git fetch composer';
-        if ($gitVersion && version_compare($gitVersion, '2.3.0-rc0', '>=') && Cache::isUsable($cachePath)) {
-            $this->io->writeError('', true, IOInterface::DEBUG);
-            $this->io->writeError(sprintf('    Cloning to cache at %s', ProcessExecutor::escape($cachePath)), true, IOInterface::DEBUG);
-            try {
-                $this->gitUtil->fetchRefOrSyncMirror($url, $cachePath, $ref);
-                if (is_dir($cachePath)) {
-                    $command =
-                        'git clone --no-checkout %cachePath% %path% --dissociate --reference %cachePath% '
-                        . '&& cd '.$flag.'%path% '
-                        . '&& git remote set-url origin %url% && git remote add composer %url%';
-                    $msg = "Cloning ".$this->getShortHash($ref).' from cache';
-                }
-            } catch (\RuntimeException $e) {
+        if (!empty($this->cachedPackages[$package->getId()][$ref])) {
+            $msg = "Cloning ".$this->getShortHash($ref).' from cache';
+            $command =
+                'git clone --no-checkout %cachePath% %path% --dissociate --reference %cachePath% '
+                . '&& cd '.$flag.'%path% '
+                . '&& git remote set-url origin %url% && git remote add composer %url%';
+        } else {
+            $msg = "Cloning ".$this->getShortHash($ref);
+            $command = 'git clone --no-checkout %url% %path% && cd '.$flag.'%path% && git remote add composer %url% && git fetch composer';
+            if (getenv('COMPOSER_DISABLE_NETWORK')) {
+                throw new \RuntimeException('The required git reference for '.$package->getName().' is not in cache and network is disabled, aborting');
             }
         }
+
         $this->io->writeError($msg);
 
         $commandCallable = function ($url) use ($path, $command, $cachePath) {
@@ -99,13 +115,51 @@ class GitDownloader extends VcsDownloader implements DvcsDownloaderInterface
     /**
      * {@inheritDoc}
      */
-    public function doUpdate(PackageInterface $initial, PackageInterface $target, $path, $url)
+    protected function doUpdate(PackageInterface $initial, PackageInterface $target, $path, $url)
     {
         GitUtil::cleanEnv();
+        $path = $this->normalizePath($path);
         if (!$this->hasMetadataRepository($path)) {
             throw new \RuntimeException('The .git directory is missing from '.$path.', see https://getcomposer.org/commit-deps for more information');
         }
 
+        $cachePath = $this->config->get('cache-vcs-dir').'/'.preg_replace('{[^a-z0-9.]}i', '-', $url).'/';
+        $ref = $target->getSourceReference();
+        $flag = Platform::isWindows() ? '/D ' : '';
+
+        if (!empty($this->cachedPackages[$target->getId()][$ref])) {
+            $msg = "Checking out ".$this->getShortHash($ref).' from cache';
+            $command = 'git rev-parse --quiet --verify %ref% || (git remote set-url composer %cachePath% && git fetch composer && git fetch --tags composer); git remote set-url composer %url%';
+        } else {
+            $msg = "Checking out ".$this->getShortHash($ref);
+            $command = 'git remote set-url composer %url% && git rev-parse --quiet --verify %ref% || (git fetch composer && git fetch --tags composer)';
+            if (getenv('COMPOSER_DISABLE_NETWORK')) {
+                throw new \RuntimeException('The required git reference for '.$target->getName().' is not in cache and network is disabled, aborting');
+            }
+        }
+
+        $this->io->writeError($msg);
+
+        $commandCallable = function ($url) use ($ref, $command, $cachePath) {
+            return str_replace(
+                array('%url%', '%ref%', '%cachePath%'),
+                array(
+                    ProcessExecutor::escape($url),
+                    ProcessExecutor::escape($ref.'^{commit}'),
+                    ProcessExecutor::escape($cachePath),
+                ),
+                $command
+            );
+        };
+
+        $this->gitUtil->runCommand($commandCallable, $url, $path);
+        if ($newRef = $this->updateToCommit($path, $ref, $target->getPrettyVersion(), $target->getReleaseDate())) {
+            if ($target->getDistReference() === $target->getSourceReference()) {
+                $target->setDistReference($newRef);
+            }
+            $target->setSourceReference($newRef);
+        }
+
         $updateOriginUrl = false;
         if (
             0 === $this->process->execute('git remote -v', $output, $path)
@@ -116,23 +170,6 @@ class GitDownloader extends VcsDownloader implements DvcsDownloaderInterface
                 $updateOriginUrl = true;
             }
         }
-
-        $ref = $target->getSourceReference();
-        $this->io->writeError(" Checking out ".$this->getShortHash($ref));
-        $command = 'git remote set-url composer %s && git rev-parse --quiet --verify %s || (git fetch composer && git fetch --tags composer)';
-
-        $commandCallable = function ($url) use ($command, $ref) {
-            return sprintf($command, ProcessExecutor::escape($url), ProcessExecutor::escape($ref.'^{commit}'));
-        };
-
-        $this->gitUtil->runCommand($commandCallable, $url, $path);
-        if ($newRef = $this->updateToCommit($path, $ref, $target->getPrettyVersion(), $target->getReleaseDate())) {
-            if ($target->getDistReference() === $target->getSourceReference()) {
-                $target->setDistReference($newRef);
-            }
-            $target->setSourceReference($newRef);
-        }
-
         if ($updateOriginUrl) {
             $this->updateOriginUrl($path, $target->getSourceUrl());
         }
diff --git a/src/Composer/Downloader/HgDownloader.php b/src/Composer/Downloader/HgDownloader.php
index add381a75..91144a13d 100644
--- a/src/Composer/Downloader/HgDownloader.php
+++ b/src/Composer/Downloader/HgDownloader.php
@@ -24,7 +24,15 @@ class HgDownloader extends VcsDownloader
     /**
      * {@inheritDoc}
      */
-    public function doInstall(PackageInterface $package, $path, $url)
+    protected function doDownload(PackageInterface $package, $path, $url, PackageInterface $prevPackage = null)
+    {
+
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    protected function doInstall(PackageInterface $package, $path, $url)
     {
         $hgUtils = new HgUtils($this->io, $this->config, $this->process);
 
@@ -44,7 +52,7 @@ class HgDownloader extends VcsDownloader
     /**
      * {@inheritDoc}
      */
-    public function doUpdate(PackageInterface $initial, PackageInterface $target, $path, $url)
+    protected function doUpdate(PackageInterface $initial, PackageInterface $target, $path, $url)
     {
         $hgUtils = new HgUtils($this->io, $this->config, $this->process);
 
diff --git a/src/Composer/Downloader/PathDownloader.php b/src/Composer/Downloader/PathDownloader.php
index 2d069fdbc..b84396416 100644
--- a/src/Composer/Downloader/PathDownloader.php
+++ b/src/Composer/Downloader/PathDownloader.php
@@ -37,7 +37,7 @@ class PathDownloader extends FileDownloader implements VcsCapableDownloaderInter
     /**
      * {@inheritdoc}
      */
-    public function download(PackageInterface $package, $path, $output = true)
+    public function download(PackageInterface $package, $path, PackageInterface $prevPackage = null, $output = true)
     {
         $url = $package->getDistUrl();
         $realUrl = realpath($url);
@@ -49,6 +49,10 @@ class PathDownloader extends FileDownloader implements VcsCapableDownloaderInter
             ));
         }
 
+        if (realpath($path) === $realUrl) {
+            return;
+        }
+
         if (strpos(realpath($path) . DIRECTORY_SEPARATOR, $realUrl . DIRECTORY_SEPARATOR) === 0) {
             // IMPORTANT NOTICE: If you wish to change this, don't. You are wasting your time and ours.
             //
@@ -71,6 +75,20 @@ class PathDownloader extends FileDownloader implements VcsCapableDownloaderInter
         $url = $package->getDistUrl();
         $realUrl = realpath($url);
 
+        if (realpath($path) === $realUrl) {
+            if ($output) {
+                $this->io->writeError(sprintf(
+                    '  - Installing <info>%s</info> (<comment>%s</comment>): Source already present',
+                    $package->getName(),
+                    $package->getFullPrettyVersion()
+                ));
+            } else {
+                $this->io->writeError('Source already present', false);
+            }
+
+            return;
+        }
+
         // Get the transport options with default values
         $transportOptions = $package->getTransportOptions() + array('symlink' => null);
 
@@ -147,7 +165,9 @@ class PathDownloader extends FileDownloader implements VcsCapableDownloaderInter
             $fileSystem->mirror($realUrl, $path, $iterator);
         }
 
-        $this->io->writeError('');
+        if ($output) {
+            $this->io->writeError('');
+        }
     }
 
     /**
@@ -155,6 +175,16 @@ class PathDownloader extends FileDownloader implements VcsCapableDownloaderInter
      */
     public function remove(PackageInterface $package, $path, $output = true)
     {
+        $realUrl = realpath($package->getDistUrl());
+
+        if ($path === $realUrl) {
+            if ($output) {
+                $this->io->writeError("  - Removing <info>" . $package->getName() . "</info> (<comment>" . $package->getFullPrettyVersion() . "</comment>), source is still present in $path");
+            }
+
+            return;
+        }
+
         /**
          * For junctions don't blindly rely on Filesystem::removeDirectory as it may be overzealous. If a process
          * inadvertently locks the file the removal will fail, but it would fall back to recursive delete which
diff --git a/src/Composer/Downloader/PerforceDownloader.php b/src/Composer/Downloader/PerforceDownloader.php
index 0427ec8c8..8be866929 100644
--- a/src/Composer/Downloader/PerforceDownloader.php
+++ b/src/Composer/Downloader/PerforceDownloader.php
@@ -24,6 +24,14 @@ class PerforceDownloader extends VcsDownloader
     /** @var Perforce */
     protected $perforce;
 
+    /**
+     * {@inheritDoc}
+     */
+    protected function doDownload(PackageInterface $package, $path, $url, PackageInterface $prevPackage = null)
+    {
+
+    }
+
     /**
      * {@inheritDoc}
      */
@@ -76,7 +84,7 @@ class PerforceDownloader extends VcsDownloader
     /**
      * {@inheritDoc}
      */
-    public function doUpdate(PackageInterface $initial, PackageInterface $target, $path, $url)
+    protected function doUpdate(PackageInterface $initial, PackageInterface $target, $path, $url)
     {
         $this->doInstall($target, $path, $url);
     }
@@ -87,8 +95,6 @@ class PerforceDownloader extends VcsDownloader
     public function getLocalChanges(PackageInterface $package, $path)
     {
         $this->io->writeError('Perforce driver does not check for local changes before overriding', true);
-
-        return null;
     }
 
     /**
diff --git a/src/Composer/Downloader/SvnDownloader.php b/src/Composer/Downloader/SvnDownloader.php
index 0aae163c6..35f01eb68 100644
--- a/src/Composer/Downloader/SvnDownloader.php
+++ b/src/Composer/Downloader/SvnDownloader.php
@@ -28,7 +28,15 @@ class SvnDownloader extends VcsDownloader
     /**
      * {@inheritDoc}
      */
-    public function doInstall(PackageInterface $package, $path, $url)
+    protected function doDownload(PackageInterface $package, $path, $url, PackageInterface $prevPackage = null)
+    {
+
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    protected function doInstall(PackageInterface $package, $path, $url)
     {
         SvnUtil::cleanEnv();
         $ref = $package->getSourceReference();
@@ -48,7 +56,7 @@ class SvnDownloader extends VcsDownloader
     /**
      * {@inheritDoc}
      */
-    public function doUpdate(PackageInterface $initial, PackageInterface $target, $path, $url)
+    protected function doUpdate(PackageInterface $initial, PackageInterface $target, $path, $url)
     {
         SvnUtil::cleanEnv();
         $ref = $target->getSourceReference();
diff --git a/src/Composer/Downloader/VcsDownloader.php b/src/Composer/Downloader/VcsDownloader.php
index b87f6433a..ce0a4bd9f 100644
--- a/src/Composer/Downloader/VcsDownloader.php
+++ b/src/Composer/Downloader/VcsDownloader.php
@@ -20,6 +20,7 @@ use Composer\Package\Version\VersionParser;
 use Composer\Util\ProcessExecutor;
 use Composer\IO\IOInterface;
 use Composer\Util\Filesystem;
+use React\Promise\PromiseInterface;
 
 /**
  * @author Jordi Boggiano <j.boggiano@seld.be>
@@ -54,9 +55,57 @@ abstract class VcsDownloader implements DownloaderInterface, ChangeReportInterfa
     /**
      * {@inheritDoc}
      */
-    public function download(PackageInterface $package, $path)
+    public function download(PackageInterface $package, $path, PackageInterface $prevPackage = null)
     {
-        // noop for now, ideally we would do a git fetch already here, or make sure the cached git repo is synced, etc.
+        if (!$package->getSourceReference()) {
+            throw new \InvalidArgumentException('Package '.$package->getPrettyName().' is missing reference information');
+        }
+
+        $urls = $this->prepareUrls($package->getSourceUrls());
+
+        while ($url = array_shift($urls)) {
+            try {
+                return $this->doDownload($package, $path, $url, $prevPackage);
+            } catch (\Exception $e) {
+                // rethrow phpunit exceptions to avoid hard to debug bug failures
+                if ($e instanceof \PHPUnit_Framework_Exception) {
+                    throw $e;
+                }
+                if ($this->io->isDebug()) {
+                    $this->io->writeError('Failed: ['.get_class($e).'] '.$e->getMessage());
+                } elseif (count($urls)) {
+                    $this->io->writeError('    Failed, trying the next URL');
+                }
+                if (!count($urls)) {
+                    throw $e;
+                }
+            }
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function prepare($type, PackageInterface $package, $path, PackageInterface $prevPackage = null)
+    {
+        if ($type === 'update') {
+            $this->cleanChanges($prevPackage, $path, true);
+        } elseif ($type === 'install') {
+            $this->filesystem->emptyDirectory($path);
+        } elseif ($type === 'uninstall') {
+            $this->cleanChanges($package, $path, false);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function cleanup($type, PackageInterface $package, $path, PackageInterface $prevPackage = null)
+    {
+        if ($type === 'update') {
+            // TODO keep track of whether prepare was called for this package
+            $this->reapplyChanges($path);
+        }
     }
 
     /**
@@ -69,32 +118,10 @@ abstract class VcsDownloader implements DownloaderInterface, ChangeReportInterfa
         }
 
         $this->io->writeError("  - Installing <info>" . $package->getName() . "</info> (<comment>" . $package->getFullPrettyVersion() . "</comment>): ", false);
-        $this->filesystem->emptyDirectory($path);
 
-        $urls = $package->getSourceUrls();
+        $urls = $this->prepareUrls($package->getSourceUrls());
         while ($url = array_shift($urls)) {
             try {
-                if (Filesystem::isLocalPath($url)) {
-                    // realpath() below will not understand
-                    // url that starts with "file://"
-                    $needle = 'file://';
-                    $isFileProtocol = false;
-                    if (0 === strpos($url, $needle)) {
-                        $url = substr($url, strlen($needle));
-                        $isFileProtocol = true;
-                    }
-
-                    // realpath() below will not understand %20 spaces etc.
-                    if (false !== strpos($url, '%')) {
-                        $url = rawurldecode($url);
-                    }
-
-                    $url = realpath($url);
-
-                    if ($isFileProtocol) {
-                        $url = $needle . $url;
-                    }
-                }
                 $this->doInstall($package, $path, $url);
                 break;
             } catch (\Exception $e) {
@@ -141,15 +168,11 @@ abstract class VcsDownloader implements DownloaderInterface, ChangeReportInterfa
         $actionName = VersionParser::isUpgrade($initial->getVersion(), $target->getVersion()) ? 'Updating' : 'Downgrading';
         $this->io->writeError("  - " . $actionName . " <info>" . $name . "</info> (<comment>" . $from . "</comment> => <comment>" . $to . "</comment>): ", false);
 
-        $this->cleanChanges($initial, $path, true);
-        $urls = $target->getSourceUrls();
+        $urls = $this->prepareUrls($target->getSourceUrls());
 
         $exception = null;
         while ($url = array_shift($urls)) {
             try {
-                if (Filesystem::isLocalPath($url)) {
-                    $url = realpath($url);
-                }
                 $this->doUpdate($initial, $target, $path, $url);
 
                 $exception = null;
@@ -167,8 +190,6 @@ abstract class VcsDownloader implements DownloaderInterface, ChangeReportInterfa
             }
         }
 
-        $this->reapplyChanges($path);
-
         // print the commit logs if in verbose mode and VCS metadata is present
         // because in case of missing metadata code would trigger another exception
         if (!$exception && $this->io->isVerbose() && $this->hasMetadataRepository($path)) {
@@ -204,7 +225,6 @@ abstract class VcsDownloader implements DownloaderInterface, ChangeReportInterfa
     public function remove(PackageInterface $package, $path)
     {
         $this->io->writeError("  - Removing <info>" . $package->getName() . "</info> (<comment>" . $package->getPrettyVersion() . "</comment>)");
-        $this->cleanChanges($package, $path, false);
         if (!$this->filesystem->removeDirectory($path)) {
             throw new \RuntimeException('Could not completely delete '.$path.', aborting.');
         }
@@ -243,7 +263,7 @@ abstract class VcsDownloader implements DownloaderInterface, ChangeReportInterfa
     }
 
     /**
-     * Guarantee that no changes have been made to the local copy
+     * Reapply previously stashes changes if applicable, only called after an update (regardless if successful or not)
      *
      * @param  string            $path
      * @throws \RuntimeException in case the operation must be aborted or the patch does not apply cleanly
@@ -252,12 +272,26 @@ abstract class VcsDownloader implements DownloaderInterface, ChangeReportInterfa
     {
     }
 
+    /**
+     * Downloads data needed to run an install/update later
+     *
+     * @param PackageInterface      $package     package instance
+     * @param string                $path        download path
+     * @param string                $url         package url
+     * @param PackageInterface|null $prevPackage previous package (in case of an update)
+     *
+     * @return PromiseInterface|null
+     */
+    abstract protected function doDownload(PackageInterface $package, $path, $url, PackageInterface $prevPackage = null);
+
     /**
      * Downloads specific package into specific folder.
      *
      * @param PackageInterface $package package instance
      * @param string           $path    download path
      * @param string           $url     package url
+     *
+     * @return PromiseInterface|null
      */
     abstract protected function doInstall(PackageInterface $package, $path, $url);
 
@@ -268,6 +302,8 @@ abstract class VcsDownloader implements DownloaderInterface, ChangeReportInterfa
      * @param PackageInterface $target  updated package
      * @param string           $path    download path
      * @param string           $url     package url
+     *
+     * @return PromiseInterface|null
      */
     abstract protected function doUpdate(PackageInterface $initial, PackageInterface $target, $path, $url);
 
@@ -289,4 +325,33 @@ abstract class VcsDownloader implements DownloaderInterface, ChangeReportInterfa
      * @return bool
      */
     abstract protected function hasMetadataRepository($path);
+
+    private function prepareUrls(array $urls)
+    {
+        foreach ($urls as $index => $url) {
+            if (Filesystem::isLocalPath($url)) {
+                // realpath() below will not understand
+                // url that starts with "file://"
+                $fileProtocol = 'file://';
+                $isFileProtocol = false;
+                if (0 === strpos($url, $fileProtocol)) {
+                    $url = substr($url, strlen($fileProtocol));
+                    $isFileProtocol = true;
+                }
+
+                // realpath() below will not understand %20 spaces etc.
+                if (false !== strpos($url, '%')) {
+                    $url = rawurldecode($url);
+                }
+
+                $urls[$index] = realpath($url);
+
+                if ($isFileProtocol) {
+                    $urls[$index] = $fileProtocol . $urls[$index];
+                }
+            }
+        }
+
+        return $urls;
+    }
 }
diff --git a/src/Composer/Downloader/ZipDownloader.php b/src/Composer/Downloader/ZipDownloader.php
index bd8d3b499..160bae1d6 100644
--- a/src/Composer/Downloader/ZipDownloader.php
+++ b/src/Composer/Downloader/ZipDownloader.php
@@ -47,7 +47,7 @@ class ZipDownloader extends ArchiveDownloader
     /**
      * {@inheritDoc}
      */
-    public function download(PackageInterface $package, $path, $output = true)
+    public function download(PackageInterface $package, $path, PackageInterface $prevPackage = null, $output = true)
     {
         if (null === self::$hasSystemUnzip) {
             $finder = new ExecutableFinder;
@@ -76,7 +76,7 @@ class ZipDownloader extends ArchiveDownloader
             }
         }
 
-        return parent::download($package, $path, $output);
+        return parent::download($package, $path, $prevPackage, $output);
     }
 
     /**
diff --git a/src/Composer/EventDispatcher/EventDispatcher.php b/src/Composer/EventDispatcher/EventDispatcher.php
index f5ac22a69..f37b1a2a4 100644
--- a/src/Composer/EventDispatcher/EventDispatcher.php
+++ b/src/Composer/EventDispatcher/EventDispatcher.php
@@ -201,7 +201,9 @@ class EventDispatcher
 
                     try {
                         /** @var InstallerEvent $event */
-                        $return = $this->dispatch($scriptName, new Script\Event($scriptName, $event->getComposer(), $event->getIO(), $event->isDevMode(), $args, $flags));
+                        $scriptEvent = new Script\Event($scriptName, $event->getComposer(), $event->getIO(), $event->isDevMode(), $args, $flags);
+                        $scriptEvent->setOriginatingEvent($event);
+                        $return = $this->dispatch($scriptName, $scriptEvent);
                     } catch (ScriptExecutionException $e) {
                         $this->io->writeError(sprintf('<error>Script %s was called via %s</error>', $callable, $event->getName()), true, IOInterface::QUIET);
                         throw $e;
diff --git a/src/Composer/Factory.php b/src/Composer/Factory.php
index 383337aa6..b6dc373a5 100644
--- a/src/Composer/Factory.php
+++ b/src/Composer/Factory.php
@@ -392,7 +392,7 @@ class Factory
                 ? substr($composerFile, 0, -4).'lock'
                 : $composerFile . '.lock';
 
-            $locker = new Package\Locker($io, new JsonFile($lockFile, null, $io), $rm, $im, file_get_contents($composerFile));
+            $locker = new Package\Locker($io, new JsonFile($lockFile, null, $io), $im, file_get_contents($composerFile));
             $composer->setLocker($locker);
         }
 
diff --git a/src/Composer/IO/BaseIO.php b/src/Composer/IO/BaseIO.php
index b63b59484..09d9d1663 100644
--- a/src/Composer/IO/BaseIO.php
+++ b/src/Composer/IO/BaseIO.php
@@ -28,6 +28,14 @@ abstract class BaseIO implements IOInterface
         return $this->authentications;
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    public function resetAuthentications()
+    {
+        $this->authentications = array();
+    }
+
     /**
      * {@inheritDoc}
      */
diff --git a/src/Composer/Installer.php b/src/Composer/Installer.php
index 791c7bcfd..8c1e9a801 100644
--- a/src/Composer/Installer.php
+++ b/src/Composer/Installer.php
@@ -632,7 +632,7 @@ class Installer
             $this->installationManager->execute($localRepo, $operation);
 
             if ($this->executeOperations) {
-                $localRepo->write();
+                $localRepo->write($this->devMode, $this->installationManager);
             }
 
             $event = 'Composer\Installer\PackageEvents::POST_PACKAGE_'.strtoupper($jobType);
diff --git a/src/Composer/Installer/InstallationManager.php b/src/Composer/Installer/InstallationManager.php
index ce10dc4da..f018c0a31 100644
--- a/src/Composer/Installer/InstallationManager.php
+++ b/src/Composer/Installer/InstallationManager.php
@@ -177,11 +177,52 @@ class InstallationManager
             $promise = $installer->download($target, $operation->getInitialPackage());
         }
 
-        if (isset($promise)) {
+        if (!empty($promise)) {
             $this->loop->wait(array($promise));
         }
 
-        $this->$method($repo, $operation);
+        $e = null;
+        try {
+            if ($method === 'install' || $method === 'uninstall') {
+                $package = $operation->getPackage();
+                $installer = $this->getInstaller($package->getType());
+                $promise = $installer->prepare($method, $package);
+            } elseif ($method === 'update') {
+                $target = $operation->getTargetPackage();
+                $targetType = $target->getType();
+                $installer = $this->getInstaller($targetType);
+                $promise = $installer->prepare('update', $target, $operation->getInitialPackage());
+            }
+
+            if (!empty($promise)) {
+                $this->loop->wait(array($promise));
+            }
+
+            $promise = $this->$method($repo, $operation);
+            if (!empty($promise)) {
+                $this->loop->wait(array($promise));
+            }
+        } catch (\Exception $e) {
+        }
+
+        if ($method === 'install' || $method === 'uninstall') {
+            $package = $operation->getPackage();
+            $installer = $this->getInstaller($package->getType());
+            $promise = $installer->cleanup($method, $package);
+        } elseif ($method === 'update') {
+            $target = $operation->getTargetPackage();
+            $targetType = $target->getType();
+            $installer = $this->getInstaller($targetType);
+            $promise = $installer->cleanup('update', $target, $operation->getInitialPackage());
+        }
+
+        if (!empty($promise)) {
+            $this->loop->wait(array($promise));
+        }
+
+        if ($e) {
+            throw $e;
+        }
     }
 
     /**
@@ -194,8 +235,10 @@ class InstallationManager
     {
         $package = $operation->getPackage();
         $installer = $this->getInstaller($package->getType());
-        $installer->install($repo, $package);
+        $promise = $installer->install($repo, $package);
         $this->markForNotification($package);
+
+        return $promise;
     }
 
     /**
@@ -214,13 +257,15 @@ class InstallationManager
 
         if ($initialType === $targetType) {
             $installer = $this->getInstaller($initialType);
-            $installer->update($repo, $initial, $target);
+            $promise = $installer->update($repo, $initial, $target);
             $this->markForNotification($target);
         } else {
             $this->getInstaller($initialType)->uninstall($repo, $initial);
             $installer = $this->getInstaller($targetType);
-            $installer->install($repo, $target);
+            $promise = $installer->install($repo, $target);
         }
+
+        return $promise;
     }
 
     /**
@@ -233,7 +278,8 @@ class InstallationManager
     {
         $package = $operation->getPackage();
         $installer = $this->getInstaller($package->getType());
-        $installer->uninstall($repo, $package);
+
+        return $installer->uninstall($repo, $package);
     }
 
     /**
diff --git a/src/Composer/Installer/InstallerInterface.php b/src/Composer/Installer/InstallerInterface.php
index 310c5fcfc..cc4bef7e9 100644
--- a/src/Composer/Installer/InstallerInterface.php
+++ b/src/Composer/Installer/InstallerInterface.php
@@ -46,26 +46,43 @@ interface InstallerInterface
     /**
      * Downloads the files needed to later install the given package.
      *
-     * @param  PackageInterface $package     package instance
-     * @param  PackageInterface $prevPackage previous package instance in case of an update
+     * @param  PackageInterface      $package     package instance
+     * @param  PackageInterface      $prevPackage previous package instance in case of an update
      * @return PromiseInterface|null
      */
     public function download(PackageInterface $package, PackageInterface $prevPackage = null);
 
+    /**
+     * Do anything that needs to be done between all downloads have been completed and the actual operation is executed
+     *
+     * All packages get first downloaded, then all together prepared, then all together installed/updated/uninstalled. Therefore
+     * for error recovery it is important to avoid failing during install/update/uninstall as much as possible, and risky things or
+     * user prompts should happen in the prepare step rather. In case of failure, cleanup() will be called so that changes can
+     * be undone as much as possible.
+     *
+     * @param  string                $type        one of install/update/uninstall
+     * @param  PackageInterface      $package     package instance
+     * @param  PackageInterface      $prevPackage previous package instance in case of an update
+     * @return PromiseInterface|null
+     */
+    public function prepare($type, PackageInterface $package, PackageInterface $prevPackage = null);
+
     /**
      * Installs specific package.
      *
-     * @param InstalledRepositoryInterface $repo    repository in which to check
-     * @param PackageInterface             $package package instance
+     * @param  InstalledRepositoryInterface $repo    repository in which to check
+     * @param  PackageInterface             $package package instance
+     * @return PromiseInterface|null
      */
     public function install(InstalledRepositoryInterface $repo, PackageInterface $package);
 
     /**
      * Updates specific package.
      *
-     * @param InstalledRepositoryInterface $repo    repository in which to check
-     * @param PackageInterface             $initial already installed package version
-     * @param PackageInterface             $target  updated version
+     * @param  InstalledRepositoryInterface $repo    repository in which to check
+     * @param  PackageInterface             $initial already installed package version
+     * @param  PackageInterface             $target  updated version
+     * @return PromiseInterface|null
      *
      * @throws InvalidArgumentException if $initial package is not installed
      */
@@ -74,11 +91,26 @@ interface InstallerInterface
     /**
      * Uninstalls specific package.
      *
-     * @param InstalledRepositoryInterface $repo    repository in which to check
-     * @param PackageInterface             $package package instance
+     * @param  InstalledRepositoryInterface $repo    repository in which to check
+     * @param  PackageInterface             $package package instance
+     * @return PromiseInterface|null
      */
     public function uninstall(InstalledRepositoryInterface $repo, PackageInterface $package);
 
+    /**
+     * Do anything to cleanup changes applied in the prepare or install/update/uninstall steps
+     *
+     * Note that cleanup will be called for all packages regardless if they failed an operation or not, to give
+     * all installers a change to cleanup things they did previously, so you need to keep track of changes
+     * applied in the installer/downloader themselves.
+     *
+     * @param  string                $type        one of install/update/uninstall
+     * @param  PackageInterface      $package     package instance
+     * @param  PackageInterface      $prevPackage previous package instance in case of an update
+     * @return PromiseInterface|null
+     */
+    public function cleanup($type, PackageInterface $package, PackageInterface $prevPackage = null);
+
     /**
      * Returns the installation path of a package
      *
diff --git a/src/Composer/Installer/LibraryInstaller.php b/src/Composer/Installer/LibraryInstaller.php
index a89553b1b..5e99e1f47 100644
--- a/src/Composer/Installer/LibraryInstaller.php
+++ b/src/Composer/Installer/LibraryInstaller.php
@@ -85,6 +85,9 @@ class LibraryInstaller implements InstallerInterface, BinaryPresenceInterface
         return (Platform::isWindows() && $this->filesystem->isJunction($installPath)) || is_link($installPath);
     }
 
+    /**
+     * {@inheritDoc}
+     */
     public function download(PackageInterface $package, PackageInterface $prevPackage = null)
     {
         $this->initializeVendorDir();
@@ -93,6 +96,28 @@ class LibraryInstaller implements InstallerInterface, BinaryPresenceInterface
         return $this->downloadManager->download($package, $downloadPath, $prevPackage);
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    public function prepare($type, PackageInterface $package, PackageInterface $prevPackage = null)
+    {
+        $this->initializeVendorDir();
+        $downloadPath = $this->getInstallPath($package);
+
+        return $this->downloadManager->prepare($type, $package, $downloadPath, $prevPackage);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function cleanup($type, PackageInterface $package, PackageInterface $prevPackage = null)
+    {
+        $this->initializeVendorDir();
+        $downloadPath = $this->getInstallPath($package);
+
+        return $this->downloadManager->cleanup($type, $package, $downloadPath, $prevPackage);
+    }
+
     /**
      * {@inheritDoc}
      */
diff --git a/src/Composer/Installer/MetapackageInstaller.php b/src/Composer/Installer/MetapackageInstaller.php
index b47c00740..1ed6beb71 100644
--- a/src/Composer/Installer/MetapackageInstaller.php
+++ b/src/Composer/Installer/MetapackageInstaller.php
@@ -55,6 +55,22 @@ class MetapackageInstaller implements InstallerInterface
         // noop
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    public function prepare($type, PackageInterface $package, PackageInterface $prevPackage = null)
+    {
+        // noop
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function cleanup($type, PackageInterface $package, PackageInterface $prevPackage = null)
+    {
+        // noop
+    }
+
     /**
      * {@inheritDoc}
      */
diff --git a/src/Composer/Installer/NoopInstaller.php b/src/Composer/Installer/NoopInstaller.php
index 51df3c305..4fe581ff5 100644
--- a/src/Composer/Installer/NoopInstaller.php
+++ b/src/Composer/Installer/NoopInstaller.php
@@ -47,6 +47,20 @@ class NoopInstaller implements InstallerInterface
     {
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    public function prepare($type, PackageInterface $package, PackageInterface $prevPackage = null)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function cleanup($type, PackageInterface $package, PackageInterface $prevPackage = null)
+    {
+    }
+
     /**
      * {@inheritDoc}
      */
diff --git a/src/Composer/Installer/PluginInstaller.php b/src/Composer/Installer/PluginInstaller.php
index 62a16fc62..a52e1937e 100644
--- a/src/Composer/Installer/PluginInstaller.php
+++ b/src/Composer/Installer/PluginInstaller.php
@@ -70,7 +70,7 @@ class PluginInstaller extends LibraryInstaller
             $this->composer->getPluginManager()->registerPackage($package, true);
         } catch (\Exception $e) {
             // Rollback installation
-            $this->io->writeError('Plugin installation failed, rolling back');
+            $this->io->writeError('Plugin initialization failed, uninstalling plugin');
             parent::uninstall($repo, $package);
             throw $e;
         }
@@ -81,12 +81,22 @@ class PluginInstaller extends LibraryInstaller
      */
     public function update(InstalledRepositoryInterface $repo, PackageInterface $initial, PackageInterface $target)
     {
-        $extra = $target->getExtra();
-        if (empty($extra['class'])) {
-            throw new \UnexpectedValueException('Error while installing '.$target->getPrettyName().', composer-plugin packages should have a class defined in their extra key to be usable.');
-        }
-
         parent::update($repo, $initial, $target);
-        $this->composer->getPluginManager()->registerPackage($target, true);
+
+        try {
+            $this->composer->getPluginManager()->deactivatePackage($initial, true);
+            $this->composer->getPluginManager()->registerPackage($target, true);
+        } catch (\Exception $e) {
+            // Rollback installation
+            $this->io->writeError('Plugin initialization failed, uninstalling plugin');
+            parent::uninstall($repo, $target);
+            throw $e;
+        }
+    }
+
+    public function uninstall(InstalledRepositoryInterface $repo, PackageInterface $package)
+    {
+        $this->composer->getPluginManager()->uninstallPackage($package, true);
+        parent::uninstall($repo, $package);
     }
 }
diff --git a/src/Composer/Installer/ProjectInstaller.php b/src/Composer/Installer/ProjectInstaller.php
index 350b220f5..069c741ec 100644
--- a/src/Composer/Installer/ProjectInstaller.php
+++ b/src/Composer/Installer/ProjectInstaller.php
@@ -71,6 +71,22 @@ class ProjectInstaller implements InstallerInterface
         return $this->downloadManager->download($package, $installPath, $prevPackage);
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    public function prepare($type, PackageInterface $package, PackageInterface $prevPackage = null)
+    {
+        $this->downloadManager->prepare($type, $package, $this->installPath, $prevPackage);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function cleanup($type, PackageInterface $package, PackageInterface $prevPackage = null)
+    {
+        $this->downloadManager->cleanup($type, $package, $this->installPath, $prevPackage);
+    }
+
     /**
      * {@inheritDoc}
      */
diff --git a/src/Composer/Json/JsonManipulator.php b/src/Composer/Json/JsonManipulator.php
index 8fe6a9f0a..e64a56f71 100644
--- a/src/Composer/Json/JsonManipulator.php
+++ b/src/Composer/Json/JsonManipulator.php
@@ -326,9 +326,10 @@ class JsonManipulator
         }
 
         // try and find a match for the subkey
-        if ($this->pregMatch('{"'.preg_quote($name).'"\s*:}i', $children)) {
+        $keyRegex = str_replace('/', '\\\\?/', preg_quote($name));
+        if ($this->pregMatch('{"'.$keyRegex.'"\s*:}i', $children)) {
             // find best match for the value of "name"
-            if (preg_match_all('{'.self::$DEFINES.'"'.preg_quote($name).'"\s*:\s*(?:(?&json))}x', $children, $matches)) {
+            if (preg_match_all('{'.self::$DEFINES.'"'.$keyRegex.'"\s*:\s*(?:(?&json))}x', $children, $matches)) {
                 $bestMatch = '';
                 foreach ($matches[0] as $match) {
                     if (strlen($bestMatch) < strlen($match)) {
diff --git a/src/Composer/Package/Locker.php b/src/Composer/Package/Locker.php
index f91d71dc5..7aad4d318 100644
--- a/src/Composer/Package/Locker.php
+++ b/src/Composer/Package/Locker.php
@@ -33,8 +33,6 @@ class Locker
 {
     /** @var JsonFile */
     private $lockFile;
-    /** @var RepositoryManager */
-    private $repositoryManager;
     /** @var InstallationManager */
     private $installationManager;
     /** @var string */
@@ -55,14 +53,12 @@ class Locker
      *
      * @param IOInterface         $io
      * @param JsonFile            $lockFile             lockfile loader
-     * @param RepositoryManager   $repositoryManager    repository manager instance
      * @param InstallationManager $installationManager  installation manager instance
      * @param string              $composerFileContents The contents of the composer file
      */
-    public function __construct(IOInterface $io, JsonFile $lockFile, RepositoryManager $repositoryManager, InstallationManager $installationManager, $composerFileContents)
+    public function __construct(IOInterface $io, JsonFile $lockFile, InstallationManager $installationManager, $composerFileContents)
     {
         $this->lockFile = $lockFile;
-        $this->repositoryManager = $repositoryManager;
         $this->installationManager = $installationManager;
         $this->hash = md5($composerFileContents);
         $this->contentHash = self::getContentHash($composerFileContents);
diff --git a/src/Composer/Plugin/PluginInterface.php b/src/Composer/Plugin/PluginInterface.php
index 5158b66f6..27b8c9754 100644
--- a/src/Composer/Plugin/PluginInterface.php
+++ b/src/Composer/Plugin/PluginInterface.php
@@ -36,4 +36,22 @@ interface PluginInterface
      * @param IOInterface $io
      */
     public function activate(Composer $composer, IOInterface $io);
+
+    /**
+     * Remove any hooks from Composer
+     *
+     * @param Composer    $composer
+     * @param IOInterface $io
+     */
+    public function deactivate(Composer $composer, IOInterface $io);
+
+    /**
+     * Prepare the plugin to be uninstalled
+     *
+     * This will be called after deactivate
+     *
+     * @param Composer    $composer
+     * @param IOInterface $io
+     */
+    public function uninstall(Composer $composer, IOInterface $io);
 }
diff --git a/src/Composer/Plugin/PluginManager.php b/src/Composer/Plugin/PluginManager.php
index 176207b41..814b0218a 100644
--- a/src/Composer/Plugin/PluginManager.php
+++ b/src/Composer/Plugin/PluginManager.php
@@ -145,7 +145,7 @@ class PluginManager
 
         $oldInstallerPlugin = ($package->getType() === 'composer-installer');
 
-        if (in_array($package->getName(), $this->registeredPlugins)) {
+        if (isset($this->registeredPlugins[$package->getName()])) {
             return;
         }
 
@@ -201,16 +201,82 @@ class PluginManager
             if ($oldInstallerPlugin) {
                 $installer = new $class($this->io, $this->composer);
                 $this->composer->getInstallationManager()->addInstaller($installer);
+                $this->registeredPlugins[$package->getName()] = $installer;
             } elseif (class_exists($class)) {
                 $plugin = new $class();
                 $this->addPlugin($plugin);
-                $this->registeredPlugins[] = $package->getName();
+                $this->registeredPlugins[$package->getName()] = $plugin;
             } elseif ($failOnMissingClasses) {
                 throw new \UnexpectedValueException('Plugin '.$package->getName().' could not be initialized, class not found: '.$class);
             }
         }
     }
 
+    /**
+     * Deactivates a plugin package
+     *
+     * If it's of type composer-installer it is unregistered from the installers
+     * instead for BC
+     *
+     * @param PackageInterface $package
+     *
+     * @throws \UnexpectedValueException
+     */
+    public function deactivatePackage(PackageInterface $package)
+    {
+        if ($this->disablePlugins) {
+            return;
+        }
+
+        $oldInstallerPlugin = ($package->getType() === 'composer-installer');
+
+        if (!isset($this->registeredPlugins[$package->getName()])) {
+            return;
+        }
+
+        if ($oldInstallerPlugin) {
+            $installer = $this->registeredPlugins[$package->getName()];
+            unset($this->registeredPlugins[$package->getName()]);
+            $this->composer->getInstallationManager()->removeInstaller($installer);
+        } else {
+            $plugin = $this->registeredPlugins[$package->getName()];
+            unset($this->registeredPlugins[$package->getName()]);
+            $this->removePlugin($plugin);
+        }
+    }
+
+    /**
+     * Uninstall a plugin package
+     *
+     * If it's of type composer-installer it is unregistered from the installers
+     * instead for BC
+     *
+     * @param PackageInterface $package
+     *
+     * @throws \UnexpectedValueException
+     */
+    public function uninstallPackage(PackageInterface $package)
+    {
+        if ($this->disablePlugins) {
+            return;
+        }
+
+        $oldInstallerPlugin = ($package->getType() === 'composer-installer');
+
+        if (!isset($this->registeredPlugins[$package->getName()])) {
+            return;
+        }
+
+        if ($oldInstallerPlugin) {
+            $this->deactivatePackage($package);
+        } else {
+            $plugin = $this->registeredPlugins[$package->getName()];
+            unset($this->registeredPlugins[$package->getName()]);
+            $this->removePlugin($plugin);
+            $this->uninstallPlugin($plugin);
+        }
+    }
+
     /**
      * Returns the version of the internal composer-plugin-api package.
      *
@@ -241,6 +307,44 @@ class PluginManager
         }
     }
 
+    /**
+     * Removes a plugin, deactivates it and removes any listener the plugin has set on the plugin instance
+     *
+     * Ideally plugin packages should be deactivated via deactivatePackage, but if you use Composer
+     * programmatically and want to deregister a plugin class directly this is a valid way
+     * to do it.
+     *
+     * @param PluginInterface $plugin plugin instance
+     */
+    public function removePlugin(PluginInterface $plugin)
+    {
+        $index = array_search($plugin, $this->plugins, true);
+        if ($index === false) {
+            return;
+        }
+
+        $this->io->writeError('Unloading plugin '.get_class($plugin), true, IOInterface::DEBUG);
+        unset($this->plugins[$index]);
+        $plugin->deactivate($this->composer, $this->io);
+
+        $this->composer->getEventDispatcher()->removeListener($plugin);
+    }
+
+    /**
+     * Notifies a plugin it is being uninstalled and should clean up
+     *
+     * Ideally plugin packages should be uninstalled via uninstallPackage, but if you use Composer
+     * programmatically and want to deregister a plugin class directly this is a valid way
+     * to do it.
+     *
+     * @param PluginInterface $plugin plugin instance
+     */
+    public function uninstallPlugin(PluginInterface $plugin)
+    {
+        $this->io->writeError('Uninstalling plugin '.get_class($plugin), true, IOInterface::DEBUG);
+        $plugin->uninstall($this->composer, $this->io);
+    }
+
     /**
      * Load all plugins and installers from a repository
      *
diff --git a/src/Composer/Repository/ArtifactRepository.php b/src/Composer/Repository/ArtifactRepository.php
index 079d34c54..aff80e4cd 100644
--- a/src/Composer/Repository/ArtifactRepository.php
+++ b/src/Composer/Repository/ArtifactRepository.php
@@ -16,6 +16,7 @@ use Composer\IO\IOInterface;
 use Composer\Json\JsonFile;
 use Composer\Package\Loader\ArrayLoader;
 use Composer\Package\Loader\LoaderInterface;
+use Composer\Util\Zip;
 
 /**
  * @author Serge Smertin <serg.smertin@gmail.com>
@@ -80,76 +81,15 @@ class ArtifactRepository extends ArrayRepository implements ConfigurableReposito
         }
     }
 
-    /**
-     * Find a file by name, returning the one that has the shortest path.
-     *
-     * @param \ZipArchive $zip
-     * @param string $filename
-     * @return bool|int
-     */
-    private function locateFile(\ZipArchive $zip, $filename)
-    {
-        $indexOfShortestMatch = false;
-        $lengthOfShortestMatch = -1;
-
-        for ($i = 0; $i < $zip->numFiles; $i++) {
-            $stat = $zip->statIndex($i);
-            if (strcmp(basename($stat['name']), $filename) === 0) {
-                $directoryName = dirname($stat['name']);
-                if ($directoryName == '.') {
-                    //if composer.json is in root directory
-                    //it has to be the one to use.
-                    return $i;
-                }
-
-                if (strpos($directoryName, '\\') !== false ||
-                   strpos($directoryName, '/') !== false) {
-                    //composer.json files below first directory are rejected
-                    continue;
-                }
-
-                $length = strlen($stat['name']);
-                if ($indexOfShortestMatch === false || $length < $lengthOfShortestMatch) {
-                    //Check it's not a directory.
-                    $contents = $zip->getFromIndex($i);
-                    if ($contents !== false) {
-                        $indexOfShortestMatch = $i;
-                        $lengthOfShortestMatch = $length;
-                    }
-                }
-            }
-        }
-
-        return $indexOfShortestMatch;
-    }
-
     private function getComposerInformation(\SplFileInfo $file)
     {
-        $zip = new \ZipArchive();
-        if ($zip->open($file->getPathname()) !== true) {
+        $json = Zip::getComposerJson($file->getPathname());
+
+        if (null === $json) {
             return false;
         }
 
-        if (0 == $zip->numFiles) {
-            $zip->close();
-
-            return false;
-        }
-
-        $foundFileIndex = $this->locateFile($zip, 'composer.json');
-        if (false === $foundFileIndex) {
-            $zip->close();
-
-            return false;
-        }
-
-        $configurationFileName = $zip->getNameIndex($foundFileIndex);
-        $zip->close();
-
-        $composerFile = "zip://{$file->getPathname()}#$configurationFileName";
-        $json = file_get_contents($composerFile);
-
-        $package = JsonFile::parseJson($json, $composerFile);
+        $package = JsonFile::parseJson($json, $file->getPathname().'#composer.json');
         $package['dist'] = array(
             'type' => 'zip',
             'url' => strtr($file->getPathname(), '\\', '/'),
diff --git a/src/Composer/Repository/FilesystemRepository.php b/src/Composer/Repository/FilesystemRepository.php
index 204aa095d..0b6563dd6 100644
--- a/src/Composer/Repository/FilesystemRepository.php
+++ b/src/Composer/Repository/FilesystemRepository.php
@@ -15,6 +15,8 @@ namespace Composer\Repository;
 use Composer\Json\JsonFile;
 use Composer\Package\Loader\ArrayLoader;
 use Composer\Package\Dumper\ArrayDumper;
+use Composer\Installer\InstallationManager;
+use Composer\Util\Filesystem;
 
 /**
  * Filesystem repository.
@@ -49,7 +51,12 @@ class FilesystemRepository extends WritableArrayRepository
         }
 
         try {
-            $packages = $this->file->read();
+            $data = $this->file->read();
+            if (isset($data['packages'])) {
+                $packages = $data['packages'];
+            } else {
+                $packages = $data;
+            }
 
             // forward compatibility for composer v2 installed.json
             if (isset($packages['packages'])) {
@@ -79,16 +86,21 @@ class FilesystemRepository extends WritableArrayRepository
     /**
      * Writes writable repository.
      */
-    public function write()
+    public function write($devMode, InstallationManager $installationManager)
     {
-        $data = array();
+        $data = array('packages' => array(), 'dev' => $devMode);
         $dumper = new ArrayDumper();
+        $fs = new Filesystem();
+        $repoDir = dirname($fs->normalizePath($this->file->getPath()));
 
         foreach ($this->getCanonicalPackages() as $package) {
-            $data[] = $dumper->dump($package);
+            $pkgArray = $dumper->dump($package);
+            $path = $installationManager->getInstallPath($package);
+            $pkgArray['install-path'] = ('' !== $path && null !== $path) ? $fs->findShortestPath($repoDir, $path, true) : null;
+            $data['packages'][] = $pkgArray;
         }
 
-        usort($data, function ($a, $b) {
+        usort($data['packages'], function ($a, $b) {
             return strcmp($a['name'], $b['name']);
         });
 
diff --git a/src/Composer/Repository/Vcs/GitHubDriver.php b/src/Composer/Repository/Vcs/GitHubDriver.php
index ee6456a89..55940e212 100644
--- a/src/Composer/Repository/Vcs/GitHubDriver.php
+++ b/src/Composer/Repository/Vcs/GitHubDriver.php
@@ -19,7 +19,6 @@ use Composer\Cache;
 use Composer\IO\IOInterface;
 use Composer\Util\GitHub;
 use Composer\Util\Http\Response;
-use Composer\Util\RemoteFilesystem;
 
 /**
  * @author Jordi Boggiano <j.boggiano@seld.be>
@@ -308,6 +307,10 @@ class GitHubDriver extends VcsDriver
      */
     protected function generateSshUrl()
     {
+        if (false !== strpos($this->originUrl, ':')) {
+            return 'ssh://git@' . $this->originUrl . '/'.$this->owner.'/'.$this->repository.'.git';
+        }
+
         return 'git@' . $this->originUrl . ':'.$this->owner.'/'.$this->repository.'.git';
     }
 
@@ -342,10 +345,10 @@ class GitHubDriver extends VcsDriver
                     $scopesIssued = array();
                     $scopesNeeded = array();
                     if ($headers = $e->getHeaders()) {
-                        if ($scopes = RemoteFilesystem::findHeaderValue($headers, 'X-OAuth-Scopes')) {
+                        if ($scopes = Response::findHeaderValue($headers, 'X-OAuth-Scopes')) {
                             $scopesIssued = explode(' ', $scopes);
                         }
-                        if ($scopes = RemoteFilesystem::findHeaderValue($headers, 'X-Accepted-OAuth-Scopes')) {
+                        if ($scopes = Response::findHeaderValue($headers, 'X-Accepted-OAuth-Scopes')) {
                             $scopesNeeded = explode(' ', $scopes);
                         }
                     }
diff --git a/src/Composer/Repository/Vcs/GitLabDriver.php b/src/Composer/Repository/Vcs/GitLabDriver.php
index 1e2775ff7..2037a8c63 100644
--- a/src/Composer/Repository/Vcs/GitLabDriver.php
+++ b/src/Composer/Repository/Vcs/GitLabDriver.php
@@ -68,9 +68,9 @@ class GitLabDriver extends VcsDriver
     private $isPrivate = true;
 
     /**
-     * @var int port number
+     * @var bool true if the origin has a port number or a path component in it
      */
-    protected $portNumber;
+    private $hasNonstandardOrigin = false;
 
     const URL_REGEX = '#^(?:(?P<scheme>https?)://(?P<domain>.+?)(?::(?P<port>[0-9]+))?/|git@(?P<domain2>[^:]+):)(?P<parts>.+)/(?P<repo>[^/]+?)(?:\.git|/)?$#';
 
@@ -95,11 +95,10 @@ class GitLabDriver extends VcsDriver
             ? $match['scheme']
             : (isset($this->repoConfig['secure-http']) && $this->repoConfig['secure-http'] === false ? 'http' : 'https')
         ;
-        $this->originUrl = $this->determineOrigin($configuredDomains, $guessedDomain, $urlParts);
+        $this->originUrl = $this->determineOrigin($configuredDomains, $guessedDomain, $urlParts, $match['port']);
 
-        if (!empty($match['port']) && true === is_numeric($match['port'])) {
-            // If it is an HTTP based URL, and it has a port
-            $this->portNumber = (int) $match['port'];
+        if (false !== strpos($this->originUrl, ':') || false !== strpos($this->originUrl, '/')) {
+            $this->hasNonstandardOrigin = true;
         }
 
         $this->namespace = implode('/', $urlParts);
@@ -260,10 +259,7 @@ class GitLabDriver extends VcsDriver
      */
     public function getApiUrl()
     {
-        $domainName = $this->originUrl;
-        $portNumber = (true === is_numeric($this->portNumber)) ? sprintf(':%s', $this->portNumber) : '';
-
-        return $this->scheme.'://'.$domainName.$portNumber.'/api/v4/projects/'.$this->urlEncodeAll($this->namespace).'%2F'.$this->urlEncodeAll($this->repository);
+        return $this->scheme.'://'.$this->originUrl.'/api/v4/projects/'.$this->urlEncodeAll($this->namespace).'%2F'.$this->urlEncodeAll($this->repository);
     }
 
     /**
@@ -362,6 +358,10 @@ class GitLabDriver extends VcsDriver
      */
     protected function generateSshUrl()
     {
+        if ($this->hasNonstandardOrigin) {
+            return 'ssh://git@'.$this->originUrl.'/'.$this->namespace.'/'.$this->repository.'.git';
+        }
+
         return 'git@' . $this->originUrl . ':'.$this->namespace.'/'.$this->repository.'.git';
     }
 
@@ -464,7 +464,7 @@ class GitLabDriver extends VcsDriver
         $guessedDomain = !empty($match['domain']) ? $match['domain'] : $match['domain2'];
         $urlParts = explode('/', $match['parts']);
 
-        if (false === self::determineOrigin((array) $config->get('gitlab-domains'), $guessedDomain, $urlParts)) {
+        if (false === self::determineOrigin((array) $config->get('gitlab-domains'), $guessedDomain, $urlParts, $match['port'])) {
             return false;
         }
 
@@ -495,16 +495,23 @@ class GitLabDriver extends VcsDriver
      * @param  array       $urlParts
      * @return bool|string
      */
-    private static function determineOrigin(array $configuredDomains, $guessedDomain, array &$urlParts)
+    private static function determineOrigin(array $configuredDomains, $guessedDomain, array &$urlParts, $portNumber)
     {
-        if (in_array($guessedDomain, $configuredDomains)) {
+        if (in_array($guessedDomain, $configuredDomains) || ($portNumber && in_array($guessedDomain.':'.$portNumber, $configuredDomains))) {
+            if ($portNumber) {
+                return $guessedDomain.':'.$portNumber;
+            }
             return $guessedDomain;
         }
 
+        if ($portNumber) {
+            $guessedDomain .= ':'.$portNumber;
+        }
+
         while (null !== ($part = array_shift($urlParts))) {
             $guessedDomain .= '/' . $part;
 
-            if (in_array($guessedDomain, $configuredDomains)) {
+            if (in_array($guessedDomain, $configuredDomains) || ($portNumber && in_array(preg_replace('{:\d+}', '', $guessedDomain), $configuredDomains))) {
                 return $guessedDomain;
             }
         }
diff --git a/src/Composer/Repository/WritableArrayRepository.php b/src/Composer/Repository/WritableArrayRepository.php
index 041e40562..3580593bb 100644
--- a/src/Composer/Repository/WritableArrayRepository.php
+++ b/src/Composer/Repository/WritableArrayRepository.php
@@ -13,6 +13,7 @@
 namespace Composer\Repository;
 
 use Composer\Package\AliasPackage;
+use Composer\Installer\InstallationManager;
 
 /**
  * Writable array repository.
@@ -24,7 +25,7 @@ class WritableArrayRepository extends ArrayRepository implements WritableReposit
     /**
      * {@inheritDoc}
      */
-    public function write()
+    public function write($devMode, InstallationManager $installationManager)
     {
     }
 
diff --git a/src/Composer/Repository/WritableRepositoryInterface.php b/src/Composer/Repository/WritableRepositoryInterface.php
index 4500005d9..c35fdb257 100644
--- a/src/Composer/Repository/WritableRepositoryInterface.php
+++ b/src/Composer/Repository/WritableRepositoryInterface.php
@@ -13,6 +13,7 @@
 namespace Composer\Repository;
 
 use Composer\Package\PackageInterface;
+use Composer\Installer\InstallationManager;
 
 /**
  * Writable repository interface.
@@ -23,8 +24,10 @@ interface WritableRepositoryInterface extends RepositoryInterface
 {
     /**
      * Writes repository (f.e. to the disc).
+     *
+     * @param bool $devMode Whether dev requirements were included or not in this installation
      */
-    public function write();
+    public function write($devMode, InstallationManager $installationManager);
 
     /**
      * Adds package to the repository.
diff --git a/src/Composer/Script/Event.php b/src/Composer/Script/Event.php
index 138f43c1a..5fab172bf 100644
--- a/src/Composer/Script/Event.php
+++ b/src/Composer/Script/Event.php
@@ -39,6 +39,11 @@ class Event extends BaseEvent
      */
     private $devMode;
 
+    /**
+     * @var BaseEvent
+     */
+    private $originatingEvent;
+
     /**
      * Constructor.
      *
@@ -55,6 +60,7 @@ class Event extends BaseEvent
         $this->composer = $composer;
         $this->io = $io;
         $this->devMode = $devMode;
+        $this->originatingEvent = null;
     }
 
     /**
@@ -86,4 +92,42 @@ class Event extends BaseEvent
     {
         return $this->devMode;
     }
+
+    /**
+     * Set the originating event.
+     *
+     * @return \Composer\EventDispatcher\Event|null
+     */
+    public function getOriginatingEvent()
+    {
+        return $this->originatingEvent;
+    }
+
+    /**
+     * Set the originating event.
+     *
+     * @param \Composer\EventDispatcher\Event $event
+     * @return $this
+     */
+    public function setOriginatingEvent(BaseEvent $event)
+    {
+        $this->originatingEvent = $this->calculateOriginatingEvent($event);
+
+        return $this;
+    }
+
+    /**
+     * Returns the upper-most event in chain.
+     *
+     * @param \Composer\EventDispatcher\Event $event
+     * @return \Composer\EventDispatcher\Event
+     */
+    private function calculateOriginatingEvent(BaseEvent $event)
+    {
+        if ($event instanceof Event && $event->getOriginatingEvent()) {
+            return $this->calculateOriginatingEvent($event->getOriginatingEvent());
+        }
+
+        return $event;
+    }
 }
diff --git a/src/Composer/Util/ErrorHandler.php b/src/Composer/Util/ErrorHandler.php
index 83e6b5ede..c4dabd1d7 100644
--- a/src/Composer/Util/ErrorHandler.php
+++ b/src/Composer/Util/ErrorHandler.php
@@ -33,6 +33,7 @@ class ErrorHandler
      *
      * @static
      * @throws \ErrorException
+     * @return bool
      */
     public static function handle($level, $message, $file, $line)
     {
@@ -63,6 +64,8 @@ class ErrorHandler
                 }, array_slice(debug_backtrace(), 2))));
             }
         }
+
+        return true;
     }
 
     /**
diff --git a/src/Composer/Util/Git.php b/src/Composer/Util/Git.php
index 74e5c286f..48e91ba84 100644
--- a/src/Composer/Util/Git.php
+++ b/src/Composer/Util/Git.php
@@ -224,6 +224,10 @@ class Git
 
     public function syncMirror($url, $dir)
     {
+        if (getenv('COMPOSER_DISABLE_NETWORK')) {
+            return false;
+        }
+
         // update the repo if it is a valid git repository
         if (is_dir($dir) && 0 === $this->process->execute('git rev-parse --git-dir', $output, $dir) && trim($output) === '.') {
             try {
@@ -260,9 +264,7 @@ class Git
             }
         }
 
-        $this->syncMirror($url, $dir);
-
-        return false;
+        return $this->syncMirror($url, $dir);
     }
 
     private function isAuthenticationFailure($url, &$match)
diff --git a/src/Composer/Util/GitLab.php b/src/Composer/Util/GitLab.php
index b2dbf2836..fb2489b01 100644
--- a/src/Composer/Util/GitLab.php
+++ b/src/Composer/Util/GitLab.php
@@ -57,7 +57,10 @@ class GitLab
      */
     public function authorizeOAuth($originUrl)
     {
-        if (!in_array($originUrl, $this->config->get('gitlab-domains'), true)) {
+        // before composer 1.9, origin URLs had no port number in them
+        $bcOriginUrl = preg_replace('{:\d+}', '', $originUrl);
+
+        if (!in_array($originUrl, $this->config->get('gitlab-domains'), true) && !in_array($bcOriginUrl, $this->config->get('gitlab-domains'), true)) {
             return false;
         }
 
@@ -77,6 +80,12 @@ class GitLab
             return true;
         }
 
+        if (isset($authTokens[$bcOriginUrl])) {
+            $this->io->setAuthentication($originUrl, $authTokens[$bcOriginUrl], 'private-token');
+
+            return true;
+        }
+
         return false;
     }
 
diff --git a/src/Composer/Util/Http/CurlDownloader.php b/src/Composer/Util/Http/CurlDownloader.php
index f7ae28a24..a163290fe 100644
--- a/src/Composer/Util/Http/CurlDownloader.php
+++ b/src/Composer/Util/Http/CurlDownloader.php
@@ -16,7 +16,6 @@ use Composer\Config;
 use Composer\IO\IOInterface;
 use Composer\Downloader\TransportException;
 use Composer\CaBundle\CaBundle;
-use Composer\Util\RemoteFilesystem;
 use Composer\Util\StreamContextFactory;
 use Composer\Util\AuthHelper;
 use Composer\Util\Url;
diff --git a/src/Composer/Util/Http/Response.php b/src/Composer/Util/Http/Response.php
index d2774c938..1b4581331 100644
--- a/src/Composer/Util/Http/Response.php
+++ b/src/Composer/Util/Http/Response.php
@@ -61,20 +61,7 @@ class Response
 
     public function getHeader($name)
     {
-        $value = null;
-        foreach ($this->headers as $header) {
-            if (preg_match('{^'.$name.':\s*(.+?)\s*$}i', $header, $match)) {
-                $value = $match[1];
-            } elseif (preg_match('{^HTTP/}i', $header)) {
-                // TODO ideally redirects would be handled in CurlDownloader/RemoteFilesystem and this becomes unnecessary
-                //
-                // In case of redirects, headers contains the headers of all responses
-                // so we reset the flag when a new response is being parsed as we are only interested in the last response
-                $value = null;
-            }
-        }
-
-        return $value;
+        return self::findHeaderValue($this->headers, $name);
     }
 
     public function getBody()
@@ -91,4 +78,27 @@ class Response
     {
         $this->request = $this->code = $this->headers = $this->body = null;
     }
+
+    /**
+     * @param  array       $headers array of returned headers like from getLastHeaders()
+     * @param  string      $name    header name (case insensitive)
+     * @return string|null
+     */
+    public static function findHeaderValue(array $headers, $name)
+    {
+        $value = null;
+        foreach ($headers as $header) {
+            if (preg_match('{^'.preg_quote($name).':\s*(.+?)\s*$}i', $header, $match)) {
+                $value = $match[1];
+            } elseif (preg_match('{^HTTP/}i', $header)) {
+                // TODO ideally redirects would be handled in CurlDownloader/RemoteFilesystem and this becomes unnecessary
+                //
+                // In case of redirects, http_response_headers contains the headers of all responses
+                // so we reset the flag when a new response is being parsed as we are only interested in the last response
+                $value = null;
+            }
+        }
+
+        return $value;
+    }
 }
diff --git a/src/Composer/Util/Perforce.php b/src/Composer/Util/Perforce.php
index 31ddeffec..52080d663 100644
--- a/src/Composer/Util/Perforce.php
+++ b/src/Composer/Util/Perforce.php
@@ -363,8 +363,6 @@ class Perforce
         while ($line !== false) {
             $line = fgets($pipe);
         }
-
-        return;
     }
 
     public function windowsLogin($password)
diff --git a/src/Composer/Util/RemoteFilesystem.php b/src/Composer/Util/RemoteFilesystem.php
index c6ba4085c..76a2176a8 100644
--- a/src/Composer/Util/RemoteFilesystem.php
+++ b/src/Composer/Util/RemoteFilesystem.php
@@ -17,6 +17,7 @@ use Composer\IO\IOInterface;
 use Composer\Downloader\TransportException;
 use Composer\CaBundle\CaBundle;
 use Composer\Util\HttpDownloader;
+use Composer\Util\Http\Response;
 
 /**
  * @author François Pluchino <francois.pluchino@opendisplay.com>
@@ -143,27 +144,6 @@ class RemoteFilesystem
         return $this->lastHeaders;
     }
 
-    /**
-     * @param  array       $headers array of returned headers like from getLastHeaders()
-     * @param  string      $name    header name (case insensitive)
-     * @return string|null
-     */
-    public static function findHeaderValue(array $headers, $name)
-    {
-        $value = null;
-        foreach ($headers as $header) {
-            if (preg_match('{^'.$name.':\s*(.+?)\s*$}i', $header, $match)) {
-                $value = $match[1];
-            } elseif (preg_match('{^HTTP/}i', $header)) {
-                // In case of redirects, http_response_headers contains the headers of all responses
-                // so we reset the flag when a new response is being parsed as we are only interested in the last response
-                $value = null;
-            }
-        }
-
-        return $value;
-    }
-
     /**
      * @param  array    $headers array of returned headers like from getLastHeaders()
      * @return int|null
@@ -286,13 +266,15 @@ class RemoteFilesystem
                 $errorMessage .= "\n";
             }
             $errorMessage .= preg_replace('{^file_get_contents\(.*?\): }', '', $msg);
+
+            return true;
         });
         try {
             $result = $this->getRemoteContents($originUrl, $fileUrl, $ctx, $http_response_header);
 
             if (!empty($http_response_header[0])) {
                 $statusCode = $this->findStatusCode($http_response_header);
-                if ($statusCode >= 400 && $this->findHeaderValue($http_response_header, 'content-type') === 'application/json') {
+                if ($statusCode >= 400 && Response::findHeaderValue($http_response_header, 'content-type') === 'application/json') {
                     HttpDownloader::outputWarnings($this->io, $originUrl, json_decode($result, true));
                 }
 
@@ -301,7 +283,7 @@ class RemoteFilesystem
                 }
             }
 
-            $contentLength = !empty($http_response_header[0]) ? $this->findHeaderValue($http_response_header, 'content-length') : null;
+            $contentLength = !empty($http_response_header[0]) ? Response::findHeaderValue($http_response_header, 'content-length') : null;
             if ($contentLength && Platform::strlen($result) < $contentLength) {
                 // alas, this is not possible via the stream callback because STREAM_NOTIFY_COMPLETED is documented, but not implemented anywhere in PHP
                 $e = new TransportException('Content-Length mismatch, received '.Platform::strlen($result).' bytes out of the expected '.$contentLength);
@@ -358,8 +340,8 @@ class RemoteFilesystem
         $locationHeader = null;
         if (!empty($http_response_header[0])) {
             $statusCode = $this->findStatusCode($http_response_header);
-            $contentType = $this->findHeaderValue($http_response_header, 'content-type');
-            $locationHeader = $this->findHeaderValue($http_response_header, 'location');
+            $contentType = Response::findHeaderValue($http_response_header, 'content-type');
+            $locationHeader = Response::findHeaderValue($http_response_header, 'location');
         }
 
         // check for bitbucket login page asking to authenticate
@@ -415,7 +397,7 @@ class RemoteFilesystem
 
         // decode gzip
         if ($result && extension_loaded('zlib') && substr($fileUrl, 0, 4) === 'http' && !$hasFollowedRedirect) {
-            $contentEncoding = $this->findHeaderValue($http_response_header, 'content-encoding');
+            $contentEncoding = Response::findHeaderValue($http_response_header, 'content-encoding');
             $decode = $contentEncoding && 'gzip' === strtolower($contentEncoding);
 
             if ($decode) {
@@ -459,6 +441,8 @@ class RemoteFilesystem
                     $errorMessage .= "\n";
                 }
                 $errorMessage .= preg_replace('{^file_put_contents\(.*?\): }', '', $msg);
+
+                return true;
             });
             $result = (bool) file_put_contents($fileName, $result);
             restore_error_handler();
@@ -696,7 +680,7 @@ class RemoteFilesystem
 
     private function handleRedirect(array $http_response_header, array $additionalOptions, $result)
     {
-        if ($locationHeader = $this->findHeaderValue($http_response_header, 'location')) {
+        if ($locationHeader = Response::findHeaderValue($http_response_header, 'location')) {
             if (parse_url($locationHeader, PHP_URL_SCHEME)) {
                 // Absolute URL; e.g. https://example.com/composer
                 $targetUrl = $locationHeader;
diff --git a/src/Composer/Util/TlsHelper.php b/src/Composer/Util/TlsHelper.php
index 34336d06c..a53212f2d 100644
--- a/src/Composer/Util/TlsHelper.php
+++ b/src/Composer/Util/TlsHelper.php
@@ -19,8 +19,6 @@ use Composer\CaBundle\CaBundle;
  */
 final class TlsHelper
 {
-    private static $useOpensslParse;
-
     /**
      * Match hostname against a certificate.
      *
diff --git a/src/Composer/Util/Url.php b/src/Composer/Util/Url.php
index c01677522..b12a2d54d 100644
--- a/src/Composer/Util/Url.php
+++ b/src/Composer/Util/Url.php
@@ -70,6 +70,9 @@ class Url
         }
 
         $origin = (string) parse_url($url, PHP_URL_HOST);
+        if ($port = parse_url($url, PHP_URL_PORT)) {
+            $origin .= ':'.$port;
+        }
 
         if (strpos($origin, '.github.com') === (strlen($origin) - 11)) {
             return 'github.com';
diff --git a/src/Composer/Util/Zip.php b/src/Composer/Util/Zip.php
new file mode 100644
index 000000000..8c79d106c
--- /dev/null
+++ b/src/Composer/Util/Zip.php
@@ -0,0 +1,108 @@
+<?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\Util;
+
+/**
+ * @author Andreas Schempp <andreas.schempp@terminal42.ch>
+ */
+class Zip
+{
+    /**
+     * Gets content of the root composer.json inside a ZIP archive.
+     *
+     * @param string $pathToZip
+     * @param string $filename
+     *
+     * @return string|null
+     */
+    public static function getComposerJson($pathToZip)
+    {
+        if (!extension_loaded('zip')) {
+            throw new \RuntimeException('The Zip Util requires PHP\'s zip extension');
+        }
+
+        $zip = new \ZipArchive();
+        if ($zip->open($pathToZip) !== true) {
+            return null;
+        }
+
+        if (0 == $zip->numFiles) {
+            $zip->close();
+
+            return null;
+        }
+
+        $foundFileIndex = self::locateFile($zip, 'composer.json');
+        if (false === $foundFileIndex) {
+            $zip->close();
+
+            return null;
+        }
+
+        $content = null;
+        $configurationFileName = $zip->getNameIndex($foundFileIndex);
+        $stream = $zip->getStream($configurationFileName);
+
+        if (false !== $stream) {
+            $content = stream_get_contents($stream);
+        }
+
+        $zip->close();
+
+        return $content;
+    }
+
+    /**
+     * Find a file by name, returning the one that has the shortest path.
+     *
+     * @param \ZipArchive $zip
+     * @param string      $filename
+     *
+     * @return bool|int
+     */
+    private static function locateFile(\ZipArchive $zip, $filename)
+    {
+        $indexOfShortestMatch = false;
+        $lengthOfShortestMatch = -1;
+
+        for ($i = 0; $i < $zip->numFiles; $i++) {
+            $stat = $zip->statIndex($i);
+            if (strcmp(basename($stat['name']), $filename) === 0) {
+                $directoryName = dirname($stat['name']);
+                if ($directoryName === '.') {
+                    //if composer.json is in root directory
+                    //it has to be the one to use.
+                    return $i;
+                }
+
+                if (strpos($directoryName, '\\') !== false ||
+                    strpos($directoryName, '/') !== false) {
+                    //composer.json files below first directory are rejected
+                    continue;
+                }
+
+                $length = strlen($stat['name']);
+                if ($indexOfShortestMatch === false || $length < $lengthOfShortestMatch) {
+                    //Check it's not a directory.
+                    $contents = $zip->getFromIndex($i);
+                    if ($contents !== false) {
+                        $indexOfShortestMatch = $i;
+                        $lengthOfShortestMatch = $length;
+                    }
+                }
+            }
+        }
+
+        return $indexOfShortestMatch;
+    }
+}
diff --git a/tests/Composer/Test/AllFunctionalTest.php b/tests/Composer/Test/AllFunctionalTest.php
index 7a3ef3ee0..5e8ebb5c4 100644
--- a/tests/Composer/Test/AllFunctionalTest.php
+++ b/tests/Composer/Test/AllFunctionalTest.php
@@ -162,18 +162,18 @@ class AllFunctionalTest extends TestCase
             }
         };
 
-        for ($i = 0, $c = count($tokens); $i < $c; $i++) {
-            if ('' === $tokens[$i] && null === $section) {
+        foreach ($tokens as $token) {
+            if ('' === $token && null === $section) {
                 continue;
             }
 
             // Handle section headers.
             if (null === $section) {
-                $section = $tokens[$i];
+                $section = $token;
                 continue;
             }
 
-            $sectionData = $tokens[$i];
+            $sectionData = $token;
 
             // Allow sections to validate, or modify their section data.
             switch ($section) {
diff --git a/tests/Composer/Test/DependencyResolver/RuleSetTest.php b/tests/Composer/Test/DependencyResolver/RuleSetTest.php
index 150e48607..70f030333 100644
--- a/tests/Composer/Test/DependencyResolver/RuleSetTest.php
+++ b/tests/Composer/Test/DependencyResolver/RuleSetTest.php
@@ -152,11 +152,4 @@ class RuleSetTest extends TestCase
 
         $this->assertContains('JOB     : Install command rule (install foo 2.1)', $ruleSet->getPrettyString($pool));
     }
-
-    private function getRuleMock()
-    {
-        return $this->getMockBuilder('Composer\DependencyResolver\Rule')
-            ->disableOriginalConstructor()
-            ->getMock();
-    }
 }
diff --git a/tests/Composer/Test/Downloader/FossilDownloaderTest.php b/tests/Composer/Test/Downloader/FossilDownloaderTest.php
index 9ab7b6b84..4ec8fed45 100644
--- a/tests/Composer/Test/Downloader/FossilDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/FossilDownloaderTest.php
@@ -48,7 +48,7 @@ class FossilDownloaderTest extends TestCase
     /**
      * @expectedException \InvalidArgumentException
      */
-    public function testDownloadForPackageWithoutSourceReference()
+    public function testInstallForPackageWithoutSourceReference()
     {
         $packageMock = $this->getMockBuilder('Composer\Package\PackageInterface')->getMock();
         $packageMock->expects($this->once())
@@ -59,7 +59,7 @@ class FossilDownloaderTest extends TestCase
         $downloader->install($packageMock, '/path');
     }
 
-    public function testDownload()
+    public function testInstall()
     {
         $packageMock = $this->getMockBuilder('Composer\Package\PackageInterface')->getMock();
         $packageMock->expects($this->any())
@@ -104,7 +104,9 @@ class FossilDownloaderTest extends TestCase
             ->will($this->returnValue(null));
 
         $downloader = $this->getDownloaderMock();
+        $downloader->prepare('update', $sourcePackageMock, '/path', $initialPackageMock);
         $downloader->update($initialPackageMock, $sourcePackageMock, '/path');
+        $downloader->cleanup('update', $sourcePackageMock, '/path', $initialPackageMock);
     }
 
     public function testUpdate()
@@ -140,7 +142,9 @@ class FossilDownloaderTest extends TestCase
             ->will($this->returnValue(0));
 
         $downloader = $this->getDownloaderMock(null, null, $processExecutor);
+        $downloader->prepare('update', $packageMock, $this->workingDir, $packageMock);
         $downloader->update($packageMock, $packageMock, $this->workingDir);
+        $downloader->cleanup('update', $packageMock, $this->workingDir, $packageMock);
     }
 
     public function testRemove()
diff --git a/tests/Composer/Test/Downloader/GitDownloaderTest.php b/tests/Composer/Test/Downloader/GitDownloaderTest.php
index b9a85a666..bf1402186 100644
--- a/tests/Composer/Test/Downloader/GitDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/GitDownloaderTest.php
@@ -17,6 +17,7 @@ use Composer\Config;
 use Composer\Test\TestCase;
 use Composer\Util\Filesystem;
 use Composer\Util\Platform;
+use Prophecy\Argument;
 
 class GitDownloaderTest extends TestCase
 {
@@ -79,7 +80,10 @@ class GitDownloaderTest extends TestCase
             ->will($this->returnValue(null));
 
         $downloader = $this->getDownloaderMock();
+        $downloader->download($packageMock, '/path');
+        $downloader->prepare('install', $packageMock, '/path');
         $downloader->install($packageMock, '/path');
+        $downloader->cleanup('install', $packageMock, '/path');
     }
 
     public function testDownload()
@@ -130,7 +134,10 @@ class GitDownloaderTest extends TestCase
             ->will($this->returnValue(0));
 
         $downloader = $this->getDownloaderMock(null, null, $processExecutor);
+        $downloader->download($packageMock, 'composerPath');
+        $downloader->prepare('install', $packageMock, 'composerPath');
         $downloader->install($packageMock, 'composerPath');
+        $downloader->cleanup('install', $packageMock, 'composerPath');
     }
 
     public function testDownloadWithCache()
@@ -195,7 +202,10 @@ class GitDownloaderTest extends TestCase
             ->will($this->returnValue(0));
 
         $downloader = $this->getDownloaderMock(null, $config, $processExecutor);
+        $downloader->download($packageMock, 'composerPath');
+        $downloader->prepare('install', $packageMock, 'composerPath');
         $downloader->install($packageMock, 'composerPath');
+        $downloader->cleanup('install', $packageMock, 'composerPath');
         @rmdir($cachePath);
     }
 
@@ -265,7 +275,10 @@ class GitDownloaderTest extends TestCase
             ->will($this->returnValue(0));
 
         $downloader = $this->getDownloaderMock(null, new Config(), $processExecutor);
+        $downloader->download($packageMock, 'composerPath');
+        $downloader->prepare('install', $packageMock, 'composerPath');
         $downloader->install($packageMock, 'composerPath');
+        $downloader->cleanup('install', $packageMock, 'composerPath');
     }
 
     public function pushUrlProvider()
@@ -329,12 +342,12 @@ class GitDownloaderTest extends TestCase
         $config->merge(array('config' => array('github-protocols' => $protocols)));
 
         $downloader = $this->getDownloaderMock(null, $config, $processExecutor);
+        $downloader->download($packageMock, 'composerPath');
+        $downloader->prepare('install', $packageMock, 'composerPath');
         $downloader->install($packageMock, 'composerPath');
+        $downloader->cleanup('install', $packageMock, 'composerPath');
     }
 
-    /**
-     * @expectedException \RuntimeException
-     */
     public function testDownloadThrowsRuntimeExceptionIfGitCommandFails()
     {
         $expectedGitCommand = $this->winCompat("git clone --no-checkout 'https://example.com/composer/composer' 'composerPath' && cd 'composerPath' && git remote add composer 'https://example.com/composer/composer' && git fetch composer");
@@ -359,8 +372,20 @@ class GitDownloaderTest extends TestCase
             ->with($this->equalTo($expectedGitCommand))
             ->will($this->returnValue(1));
 
-        $downloader = $this->getDownloaderMock(null, null, $processExecutor);
-        $downloader->install($packageMock, 'composerPath');
+        // not using PHPUnit's expected exception because Prophecy exceptions extend from RuntimeException too so it is not safe
+        try {
+            $downloader = $this->getDownloaderMock(null, null, $processExecutor);
+            $downloader->download($packageMock, 'composerPath');
+            $downloader->prepare('install', $packageMock, 'composerPath');
+            $downloader->install($packageMock, 'composerPath');
+            $downloader->cleanup('install', $packageMock, 'composerPath');
+            $this->fail('This test should throw');
+        } catch (\RuntimeException $e) {
+            if ('RuntimeException' !== get_class($e)) {
+                throw $e;
+            }
+            $this->assertEquals('RuntimeException', get_class($e));
+        }
     }
 
     /**
@@ -375,7 +400,10 @@ class GitDownloaderTest extends TestCase
             ->will($this->returnValue(null));
 
         $downloader = $this->getDownloaderMock();
+        $downloader->download($sourcePackageMock, '/path', $initialPackageMock);
+        $downloader->prepare('update', $sourcePackageMock, '/path', $initialPackageMock);
         $downloader->update($initialPackageMock, $sourcePackageMock, '/path');
+        $downloader->cleanup('update', $sourcePackageMock, '/path', $initialPackageMock);
     }
 
     public function testUpdate()
@@ -392,39 +420,22 @@ class GitDownloaderTest extends TestCase
         $packageMock->expects($this->any())
             ->method('getVersion')
             ->will($this->returnValue('1.0.0.0'));
-        $processExecutor = $this->getMockBuilder('Composer\Util\ProcessExecutor')->getMock();
-        $processExecutor->expects($this->at(0))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git show-ref --head -d")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(1))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git status --porcelain --untracked-files=no")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(2))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git remote -v")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(3))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git remote -v")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(4))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat($expectedGitUpdateCommand)), $this->equalTo(null), $this->equalTo($this->winCompat($this->workingDir)))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(5))
-            ->method('execute')
-            ->with($this->equalTo('git branch -r'))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(6))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git checkout 'ref' -- && git reset --hard 'ref' --")), $this->equalTo(null), $this->equalTo($this->winCompat($this->workingDir)))
-            ->will($this->returnValue(0));
+
+        $process = $this->prophesize('Composer\Util\ProcessExecutor');
+        $process->execute($this->winCompat('git --version'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git show-ref --head -d'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git status --porcelain --untracked-files=no'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git remote -v'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git branch -r'), Argument::cetera())->willReturn(0);
+        $process->execute($expectedGitUpdateCommand, null, $this->winCompat($this->workingDir))->willReturn(0)->shouldBeCalled();
+        $process->execute($this->winCompat("git checkout 'ref' -- && git reset --hard 'ref' --"), null, $this->winCompat($this->workingDir))->willReturn(0)->shouldBeCalled();
 
         $this->fs->ensureDirectoryExists($this->workingDir.'/.git');
-        $downloader = $this->getDownloaderMock(null, new Config(), $processExecutor);
+        $downloader = $this->getDownloaderMock(null, new Config(), $process->reveal());
+        $downloader->download($packageMock, $this->workingDir, $packageMock);
+        $downloader->prepare('update', $packageMock, $this->workingDir, $packageMock);
         $downloader->update($packageMock, $packageMock, $this->workingDir);
+        $downloader->cleanup('update', $packageMock, $this->workingDir, $packageMock);
     }
 
     public function testUpdateWithNewRepoUrl()
@@ -444,27 +455,20 @@ class GitDownloaderTest extends TestCase
         $packageMock->expects($this->any())
             ->method('getVersion')
             ->will($this->returnValue('1.0.0.0'));
+
         $processExecutor = $this->getMockBuilder('Composer\Util\ProcessExecutor')->getMock();
         $processExecutor->expects($this->at(0))
             ->method('execute')
-            ->with($this->equalTo($this->winCompat("git show-ref --head -d")))
+            ->with($this->equalTo($this->winCompat("git --version")))
             ->will($this->returnValue(0));
         $processExecutor->expects($this->at(1))
             ->method('execute')
-            ->with($this->equalTo($this->winCompat("git status --porcelain --untracked-files=no")))
+            ->with($this->equalTo($this->winCompat("git show-ref --head -d")))
             ->will($this->returnValue(0));
         $processExecutor->expects($this->at(2))
             ->method('execute')
-            ->with($this->equalTo($this->winCompat("git remote -v")))
-            ->will($this->returnCallback(function ($cmd, &$output, $cwd) {
-                $output = 'origin https://github.com/old/url (fetch)
-origin https://github.com/old/url (push)
-composer https://github.com/old/url (fetch)
-composer https://github.com/old/url (push)
-';
-
-                return 0;
-            }));
+            ->with($this->equalTo($this->winCompat("git status --porcelain --untracked-files=no")))
+            ->will($this->returnValue(0));
         $processExecutor->expects($this->at(3))
             ->method('execute')
             ->with($this->equalTo($this->winCompat("git remote -v")))
@@ -482,26 +486,41 @@ composer https://github.com/old/url (push)
             ->with($this->equalTo($this->winCompat("git checkout 'ref' -- && git reset --hard 'ref' --")), $this->equalTo(null), $this->equalTo($this->winCompat($this->workingDir)))
             ->will($this->returnValue(0));
         $processExecutor->expects($this->at(7))
+            ->method('execute')
+            ->with($this->equalTo($this->winCompat("git remote -v")))
+            ->will($this->returnCallback(function ($cmd, &$output, $cwd) {
+                $output = 'origin https://github.com/old/url (fetch)
+origin https://github.com/old/url (push)
+composer https://github.com/old/url (fetch)
+composer https://github.com/old/url (push)
+';
+
+                return 0;
+            }));
+        $processExecutor->expects($this->at(8))
             ->method('execute')
             ->with($this->equalTo($this->winCompat("git remote set-url origin 'https://github.com/composer/composer'")), $this->equalTo(null), $this->equalTo($this->winCompat($this->workingDir)))
             ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(8))
+        $processExecutor->expects($this->at(9))
             ->method('execute')
             ->with($this->equalTo($this->winCompat("git remote set-url --push origin 'git@github.com:composer/composer.git'")), $this->equalTo(null), $this->equalTo($this->winCompat($this->workingDir)))
             ->will($this->returnValue(0));
 
         $this->fs->ensureDirectoryExists($this->workingDir.'/.git');
         $downloader = $this->getDownloaderMock(null, new Config(), $processExecutor);
+        $downloader->download($packageMock, $this->workingDir, $packageMock);
+        $downloader->prepare('update', $packageMock, $this->workingDir, $packageMock);
         $downloader->update($packageMock, $packageMock, $this->workingDir);
+        $downloader->cleanup('update', $packageMock, $this->workingDir, $packageMock);
     }
 
     /**
      * @group failing
-     * @expectedException \RuntimeException
      */
     public function testUpdateThrowsRuntimeExceptionIfGitCommandFails()
     {
         $expectedGitUpdateCommand = $this->winCompat("git remote set-url composer 'https://github.com/composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)");
+        $expectedGitUpdateCommand2 = $this->winCompat("git remote set-url composer 'git@github.com:composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)");
 
         $packageMock = $this->getMockBuilder('Composer\Package\PackageInterface')->getMock();
         $packageMock->expects($this->any())
@@ -513,36 +532,38 @@ composer https://github.com/old/url (push)
         $packageMock->expects($this->any())
             ->method('getVersion')
             ->will($this->returnValue('1.0.0.0'));
-        $processExecutor = $this->getMockBuilder('Composer\Util\ProcessExecutor')->getMock();
-        $processExecutor->expects($this->at(0))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git show-ref --head -d")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(1))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git status --porcelain --untracked-files=no")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(2))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git remote -v")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(3))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git remote -v")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(4))
-            ->method('execute')
-            ->with($this->equalTo($expectedGitUpdateCommand))
-            ->will($this->returnValue(1));
+
+        $process = $this->prophesize('Composer\Util\ProcessExecutor');
+        $process->execute($this->winCompat('git --version'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git show-ref --head -d'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git status --porcelain --untracked-files=no'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git remote -v'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git branch -r'), Argument::cetera())->willReturn(0);
+        $process->execute($expectedGitUpdateCommand, null, $this->winCompat($this->workingDir))->willReturn(1)->shouldBeCalled();
+        $process->execute($expectedGitUpdateCommand2, null, $this->winCompat($this->workingDir))->willReturn(1)->shouldBeCalled();
+        $process->getErrorOutput()->willReturn('');
 
         $this->fs->ensureDirectoryExists($this->workingDir.'/.git');
-        $downloader = $this->getDownloaderMock(null, new Config(), $processExecutor);
-        $downloader->update($packageMock, $packageMock, $this->workingDir);
+
+        // not using PHPUnit's expected exception because Prophecy exceptions extend from RuntimeException too so it is not safe
+        try {
+            $downloader = $this->getDownloaderMock(null, new Config(), $process->reveal());
+            $downloader->download($packageMock, $this->workingDir, $packageMock);
+            $downloader->prepare('update', $packageMock, $this->workingDir, $packageMock);
+            $downloader->update($packageMock, $packageMock, $this->workingDir);
+            $downloader->cleanup('update', $packageMock, $this->workingDir, $packageMock);
+            $this->fail('This test should throw');
+        } catch (\RuntimeException $e) {
+            if ('RuntimeException' !== get_class($e)) {
+                throw $e;
+            }
+            $this->assertEquals('RuntimeException', get_class($e));
+        }
     }
 
     public function testUpdateDoesntThrowsRuntimeExceptionIfGitCommandFailsAtFirstButIsAbleToRecover()
     {
-        $expectedFirstGitUpdateCommand = $this->winCompat("git remote set-url composer '' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)");
+        $expectedFirstGitUpdateCommand = $this->winCompat("git remote set-url composer '".(Platform::isWindows() ? 'C:\\' : '/')."' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)");
         $expectedSecondGitUpdateCommand = $this->winCompat("git remote set-url composer 'https://github.com/composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)");
 
         $packageMock = $this->getMockBuilder('Composer\Package\PackageInterface')->getMock();
@@ -554,52 +575,24 @@ composer https://github.com/old/url (push)
             ->will($this->returnValue('1.0.0.0'));
         $packageMock->expects($this->any())
             ->method('getSourceUrls')
-            ->will($this->returnValue(array('/foo/bar', 'https://github.com/composer/composer')));
-        $processExecutor = $this->getMockBuilder('Composer\Util\ProcessExecutor')->getMock();
-        $processExecutor->expects($this->at(0))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git show-ref --head -d")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(1))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git status --porcelain --untracked-files=no")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(2))
-           ->method('execute')
-            ->with($this->equalTo($this->winCompat("git remote -v")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(3))
-           ->method('execute')
-            ->with($this->equalTo($this->winCompat("git remote -v")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(4))
-            ->method('execute')
-            ->with($this->equalTo($expectedFirstGitUpdateCommand))
-            ->will($this->returnValue(1));
-        $processExecutor->expects($this->at(6))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git --version")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(7))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git remote -v")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(8))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git remote -v")))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(9))
-            ->method('execute')
-            ->with($this->equalTo($expectedSecondGitUpdateCommand))
-            ->will($this->returnValue(0));
-        $processExecutor->expects($this->at(11))
-            ->method('execute')
-            ->with($this->equalTo($this->winCompat("git checkout 'ref' -- && git reset --hard 'ref' --")), $this->equalTo(null), $this->equalTo($this->winCompat($this->workingDir)))
-            ->will($this->returnValue(0));
+            ->will($this->returnValue(array(Platform::isWindows() ? 'C:\\' : '/', 'https://github.com/composer/composer')));
+
+        $process = $this->prophesize('Composer\Util\ProcessExecutor');
+        $process->execute($this->winCompat('git --version'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git show-ref --head -d'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git status --porcelain --untracked-files=no'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git remote -v'), Argument::cetera())->willReturn(0);
+        $process->execute($this->winCompat('git branch -r'), Argument::cetera())->willReturn(0);
+        $process->execute($expectedFirstGitUpdateCommand, Argument::cetera())->willReturn(1)->shouldBeCalled();
+        $process->execute($expectedSecondGitUpdateCommand, Argument::cetera())->willReturn(0)->shouldBeCalled();
+        $process->execute($this->winCompat("git checkout 'ref' -- && git reset --hard 'ref' --"), null, $this->winCompat($this->workingDir))->willReturn(0)->shouldBeCalled();
 
         $this->fs->ensureDirectoryExists($this->workingDir.'/.git');
-        $downloader = $this->getDownloaderMock(null, new Config(), $processExecutor);
+        $downloader = $this->getDownloaderMock(null, new Config(), $process->reveal());
+        $downloader->download($packageMock, $this->workingDir, $packageMock);
+        $downloader->prepare('update', $packageMock, $this->workingDir, $packageMock);
         $downloader->update($packageMock, $packageMock, $this->workingDir);
+        $downloader->cleanup('update', $packageMock, $this->workingDir, $packageMock);
     }
 
     public function testDowngradeShowsAppropriateMessage()
@@ -644,7 +637,10 @@ composer https://github.com/old/url (push)
 
         $this->fs->ensureDirectoryExists($this->workingDir.'/.git');
         $downloader = $this->getDownloaderMock($ioMock, null, $processExecutor);
+        $downloader->download($newPackage, $this->workingDir, $oldPackage);
+        $downloader->prepare('update', $newPackage, $this->workingDir, $oldPackage);
         $downloader->update($oldPackage, $newPackage, $this->workingDir);
+        $downloader->cleanup('update', $newPackage, $this->workingDir, $oldPackage);
     }
 
     public function testNotUsingDowngradingWithReferences()
@@ -679,11 +675,14 @@ composer https://github.com/old/url (push)
         $ioMock = $this->getMockBuilder('Composer\IO\IOInterface')->getMock();
         $ioMock->expects($this->at(0))
             ->method('writeError')
-            ->with($this->stringContains('updating'));
+            ->with($this->stringContains('Updating'));
 
         $this->fs->ensureDirectoryExists($this->workingDir.'/.git');
         $downloader = $this->getDownloaderMock($ioMock, null, $processExecutor);
+        $downloader->download($newPackage, $this->workingDir, $oldPackage);
+        $downloader->prepare('update', $newPackage, $this->workingDir, $oldPackage);
         $downloader->update($oldPackage, $newPackage, $this->workingDir);
+        $downloader->cleanup('update', $newPackage, $this->workingDir, $oldPackage);
     }
 
     public function testRemove()
@@ -703,7 +702,9 @@ composer https://github.com/old/url (push)
             ->will($this->returnValue(true));
 
         $downloader = $this->getDownloaderMock(null, null, $processExecutor, $filesystem);
+        $downloader->prepare('uninstall', $packageMock, 'composerPath');
         $downloader->remove($packageMock, 'composerPath');
+        $downloader->cleanup('uninstall', $packageMock, 'composerPath');
     }
 
     public function testGetInstallationSource()
diff --git a/tests/Composer/Test/Downloader/HgDownloaderTest.php b/tests/Composer/Test/Downloader/HgDownloaderTest.php
index a4219d143..c69d497ce 100644
--- a/tests/Composer/Test/Downloader/HgDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/HgDownloaderTest.php
@@ -98,7 +98,9 @@ class HgDownloaderTest extends TestCase
             ->will($this->returnValue(null));
 
         $downloader = $this->getDownloaderMock();
+        $downloader->prepare('update', $sourcePackageMock, '/path', $initialPackageMock);
         $downloader->update($initialPackageMock, $sourcePackageMock, '/path');
+        $downloader->cleanup('update', $sourcePackageMock, '/path', $initialPackageMock);
     }
 
     public function testUpdate()
@@ -129,7 +131,9 @@ class HgDownloaderTest extends TestCase
             ->will($this->returnValue(0));
 
         $downloader = $this->getDownloaderMock(null, null, $processExecutor);
+        $downloader->prepare('update', $packageMock, $this->workingDir, $packageMock);
         $downloader->update($packageMock, $packageMock, $this->workingDir);
+        $downloader->cleanup('update', $packageMock, $this->workingDir, $packageMock);
     }
 
     public function testRemove()
@@ -148,7 +152,9 @@ class HgDownloaderTest extends TestCase
             ->will($this->returnValue(true));
 
         $downloader = $this->getDownloaderMock(null, null, $processExecutor, $filesystem);
+        $downloader->prepare('uninstall', $packageMock, 'composerPath');
         $downloader->remove($packageMock, 'composerPath');
+        $downloader->cleanup('uninstall', $packageMock, 'composerPath');
     }
 
     public function testGetInstallationSource()
diff --git a/tests/Composer/Test/Downloader/ZipDownloaderTest.php b/tests/Composer/Test/Downloader/ZipDownloaderTest.php
index e69149271..63c407218 100644
--- a/tests/Composer/Test/Downloader/ZipDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/ZipDownloaderTest.php
@@ -338,7 +338,7 @@ class ZipDownloaderTest extends TestCase
 
 class MockedZipDownloader extends ZipDownloader
 {
-    public function download(PackageInterface $package, $path, $output = true)
+    public function download(PackageInterface $package, $path, PackageInterface $prevPackage = null, $output = true)
     {
         return;
     }
diff --git a/tests/Composer/Test/Fixtures/installer/update-changes-url.test b/tests/Composer/Test/Fixtures/installer/update-changes-url.test
index c9df288f6..3df99678c 100644
--- a/tests/Composer/Test/Fixtures/installer/update-changes-url.test
+++ b/tests/Composer/Test/Fixtures/installer/update-changes-url.test
@@ -17,37 +17,38 @@ g/g is dev and installed in a different ref than the #ref, so it gets updated an
                 {
                     "name": "a/a", "version": "dev-master",
                     "source": { "reference": "2222222222222222222222222222222222222222", "url": "https://github.com/a/newa", "type": "git" },
-                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/a/newa/zipball/2222222222222222222222222222222222222222", "type": "zip" }
+                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/a/newa/tarball/2222222222222222222222222222222222222222", "type": "tar", "shasum": "newsum" }
                 },
                 {
                     "name": "b/b", "version": "2.0.3",
                     "source": { "reference": "2222222222222222222222222222222222222222", "url": "https://github.com/b/newb", "type": "git" },
-                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/b/newb/zipball/2222222222222222222222222222222222222222", "type": "zip" }
+                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/b/newb/tarball/2222222222222222222222222222222222222222", "type": "tar", "shasum": "newsum" }
                 },
                 {
                     "name": "c/c", "version": "1.0.0",
                     "source": { "reference": "2222222222222222222222222222222222222222", "url": "https://github.com/c/newc", "type": "git" },
-                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/c/newc/zipball/2222222222222222222222222222222222222222", "type": "zip" }
+                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/c/newc/tarball/2222222222222222222222222222222222222222", "type": "tar", "shasum": "newsum" }
                 },
                 {
                     "name": "d/d", "version": "dev-master",
                     "source": { "reference": "2222222222222222222222222222222222222222", "url": "https://github.com/d/newd", "type": "git" },
-                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/d/newd/zipball/2222222222222222222222222222222222222222", "type": "zip" }
+                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/d/newd/tarball/2222222222222222222222222222222222222222", "type": "tar", "shasum": "newsum" }
                 },
                 {
                     "name": "e/e", "version": "dev-master",
                     "source": { "reference": "2222222222222222222222222222222222222222", "url": "https://github.com/e/newe", "type": "git" },
-                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/e/newe/zipball/2222222222222222222222222222222222222222", "type": "zip" }
+                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/e/newe/tarball/2222222222222222222222222222222222222222", "type": "tar", "shasum": "newsum" }
                 },
                 {
                     "name": "f/f", "version": "dev-master",
                     "source": { "reference": "2222222222222222222222222222222222222222", "url": "https://github.com/f/newf", "type": "git" },
-                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/f/newf/zipball/2222222222222222222222222222222222222222", "type": "zip" }
+                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/f/newf/tarball/2222222222222222222222222222222222222222", "type": "tar", "shasum": "newsum" },
+                    "transport-options": { "foo": "bar2" }
                 },
                 {
                     "name": "g/g", "version": "dev-master",
                     "source": { "reference": "2222222222222222222222222222222222222222", "url": "https://github.com/g/newg", "type": "git" },
-                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/g/newg/zipball/2222222222222222222222222222222222222222", "type": "zip" }
+                    "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/g/newg/tarball/2222222222222222222222222222222222222222", "type": "tar", "shasum": "newsum" }
                 }
             ]
         }
@@ -67,32 +68,34 @@ g/g is dev and installed in a different ref than the #ref, so it gets updated an
     {
         "name": "a/a", "version": "dev-master",
         "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/a/a", "type": "git" },
-        "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/a/a/zipball/1111111111111111111111111111111111111111", "type": "zip" }
+        "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/a/a/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" }
     },
     {
         "name": "b/b", "version": "2.0.3",
         "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/b/b", "type": "git" },
-        "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/b/b/zipball/1111111111111111111111111111111111111111", "type": "zip" }
+        "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/b/b/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" }
     },
     {
         "name": "c/c", "version": "1.0.0",
         "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/c/c", "type": "git" },
-        "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/c/c/zipball/1111111111111111111111111111111111111111", "type": "zip" }
+        "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/c/c/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" }
     },
     {
         "name": "d/d", "version": "dev-master",
         "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/d/d", "type": "git" },
-        "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/d/d/zipball/1111111111111111111111111111111111111111", "type": "zip" }
+        "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/d/d/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" }
     },
     {
         "name": "f/f", "version": "dev-master",
         "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/f/f", "type": "git" },
-        "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/f/f/zipball/1111111111111111111111111111111111111111", "type": "zip" }
+        "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/f/f/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" },
+        "transport-options": { "foo": "bar" }
     },
     {
         "name": "g/g", "version": "dev-master",
         "source": { "reference": "0000000000000000000000000000000000000000", "url": "https://github.com/g/g", "type": "git" },
-        "dist": { "reference": "0000000000000000000000000000000000000000", "url": "https://api.github.com/repos/g/g/zipball/0000000000000000000000000000000000000000", "type": "zip" }
+        "dist": { "reference": "0000000000000000000000000000000000000000", "url": "https://api.github.com/repos/g/g/zipball/0000000000000000000000000000000000000000", "type": "zip", "shasum": "oldsum" },
+        "transport-options": { "foo": "bar" }
     }
 ]
 --LOCK--
@@ -101,38 +104,40 @@ g/g is dev and installed in a different ref than the #ref, so it gets updated an
         {
             "name": "a/a", "version": "dev-master",
             "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/a/a", "type": "git" },
-            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/a/a/zipball/1111111111111111111111111111111111111111", "type": "zip" },
+            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/a/a/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" },
             "type": "library"
         },
         {
             "name": "b/b", "version": "2.0.3",
             "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/b/b", "type": "git" },
-            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/b/b/zipball/1111111111111111111111111111111111111111", "type": "zip" },
+            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/b/b/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" },
             "type": "library"
         },
         {
             "name": "c/c", "version": "1.0.0",
             "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/c/c", "type": "git" },
-            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/c/c/zipball/1111111111111111111111111111111111111111", "type": "zip" },
+            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/c/c/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" },
             "type": "library"
         },
         {
             "name": "d/d", "version": "dev-master",
             "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/d/d", "type": "git" },
-            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/d/d/zipball/1111111111111111111111111111111111111111", "type": "zip" },
+            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/d/d/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" },
             "type": "library"
         },
         {
             "name": "f/f", "version": "dev-master",
             "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/f/f", "type": "git" },
-            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/f/f/zipball/1111111111111111111111111111111111111111", "type": "zip" },
-            "type": "library"
+            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/f/f/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" },
+            "type": "library",
+            "transport-options": { "foo": "bar" }
         },
         {
             "name": "g/g", "version": "dev-master",
             "source": { "reference": "0000000000000000000000000000000000000000", "url": "https://github.com/g/g", "type": "git" },
-            "dist": { "reference": "0000000000000000000000000000000000000000", "url": "https://api.github.com/repos/g/g/zipball/0000000000000000000000000000000000000000", "type": "zip" },
-            "type": "library"
+            "dist": { "reference": "0000000000000000000000000000000000000000", "url": "https://api.github.com/repos/g/g/zipball/0000000000000000000000000000000000000000", "type": "zip", "shasum": "oldsum" },
+            "type": "library",
+            "transport-options": { "foo": "bar" }
         }
     ],
     "packages-dev": [],
@@ -150,43 +155,44 @@ g/g is dev and installed in a different ref than the #ref, so it gets updated an
         {
             "name": "a/a", "version": "dev-master",
             "source": { "reference": "2222222222222222222222222222222222222222", "url": "https://github.com/a/newa", "type": "git" },
-            "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/a/newa/zipball/2222222222222222222222222222222222222222", "type": "zip" },
+            "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/a/newa/tarball/2222222222222222222222222222222222222222", "type": "tar", "shasum": "newsum" },
             "type": "library"
         },
         {
             "name": "b/b", "version": "2.0.3",
             "source": { "reference": "2222222222222222222222222222222222222222", "url": "https://github.com/b/newb", "type": "git" },
-            "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/b/newb/zipball/2222222222222222222222222222222222222222", "type": "zip" },
+            "dist": { "reference": "2222222222222222222222222222222222222222", "url": "https://api.github.com/repos/b/newb/tarball/2222222222222222222222222222222222222222", "type": "tar", "shasum": "newsum" },
             "type": "library"
         },
         {
             "name": "c/c", "version": "1.0.0",
             "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/c/c", "type": "git" },
-            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/c/c/zipball/1111111111111111111111111111111111111111", "type": "zip" },
+            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/c/c/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" },
             "type": "library"
         },
         {
             "name": "d/d", "version": "dev-master",
             "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/d/newd", "type": "git" },
-            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/d/newd/zipball/1111111111111111111111111111111111111111", "type": "zip" },
+            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/d/newd/tarball/1111111111111111111111111111111111111111", "type": "tar", "shasum": "newsum" },
             "type": "library"
         },
         {
             "name": "e/e", "version": "dev-master",
             "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/e/newe", "type": "git" },
-            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/e/newe/zipball/1111111111111111111111111111111111111111", "type": "zip" },
+            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/e/newe/tarball/1111111111111111111111111111111111111111", "type": "tar", "shasum": "newsum" },
             "type": "library"
         },
         {
             "name": "f/f", "version": "dev-master",
             "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/f/f", "type": "git" },
-            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/f/f/zipball/1111111111111111111111111111111111111111", "type": "zip" },
-            "type": "library"
+            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/f/f/zipball/1111111111111111111111111111111111111111", "type": "zip", "shasum": "oldsum" },
+            "type": "library",
+            "transport-options": { "foo": "bar" }
         },
         {
             "name": "g/g", "version": "dev-master",
             "source": { "reference": "1111111111111111111111111111111111111111", "url": "https://github.com/g/newg", "type": "git" },
-            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/g/newg/zipball/1111111111111111111111111111111111111111", "type": "zip" },
+            "dist": { "reference": "1111111111111111111111111111111111111111", "url": "https://api.github.com/repos/g/newg/tarball/1111111111111111111111111111111111111111", "type": "tar", "shasum": "newsum" },
             "type": "library"
         }
     ],
diff --git a/tests/Composer/Test/InstallerTest.php b/tests/Composer/Test/InstallerTest.php
index 05c49f6a9..89385c288 100644
--- a/tests/Composer/Test/InstallerTest.php
+++ b/tests/Composer/Test/InstallerTest.php
@@ -246,7 +246,7 @@ class InstallerTest extends TestCase
         }
 
         $contents = json_encode($composerConfig);
-        $locker = new Locker($io, $lockJsonMock, $repositoryManager, $composer->getInstallationManager(), $contents);
+        $locker = new Locker($io, $lockJsonMock, $composer->getInstallationManager(), $contents);
         $composer->setLocker($locker);
 
         $eventDispatcher = $this->getMockBuilder('Composer\EventDispatcher\EventDispatcher')->disableOriginalConstructor()->getMock();
diff --git a/tests/Composer/Test/Json/JsonManipulatorTest.php b/tests/Composer/Test/Json/JsonManipulatorTest.php
index d8bc7c200..8bc7831af 100644
--- a/tests/Composer/Test/Json/JsonManipulatorTest.php
+++ b/tests/Composer/Test/Json/JsonManipulatorTest.php
@@ -1448,6 +1448,22 @@ class JsonManipulatorTest extends TestCase
     "repositories": {
     }
 }
+',
+            ),
+            'works on simple ones escaped slash' => array(
+                '{
+    "repositories": {
+        "foo\/bar": {
+            "bar": "baz"
+        }
+    }
+}',
+                'foo/bar',
+                true,
+                '{
+    "repositories": {
+    }
+}
 ',
             ),
             'works on simple ones middle' => array(
diff --git a/tests/Composer/Test/Mock/InstalledFilesystemRepositoryMock.php b/tests/Composer/Test/Mock/InstalledFilesystemRepositoryMock.php
index 9c11dc307..574cfbd83 100644
--- a/tests/Composer/Test/Mock/InstalledFilesystemRepositoryMock.php
+++ b/tests/Composer/Test/Mock/InstalledFilesystemRepositoryMock.php
@@ -13,6 +13,7 @@
 namespace Composer\Test\Mock;
 
 use Composer\Repository\InstalledFilesystemRepository;
+use Composer\Installer\InstallationManager;
 
 class InstalledFilesystemRepositoryMock extends InstalledFilesystemRepository
 {
@@ -20,7 +21,7 @@ class InstalledFilesystemRepositoryMock extends InstalledFilesystemRepository
     {
     }
 
-    public function write()
+    public function write($devMode, InstallationManager $installationManager)
     {
     }
 }
diff --git a/tests/Composer/Test/Package/Loader/ArrayLoaderTest.php b/tests/Composer/Test/Package/Loader/ArrayLoaderTest.php
index e3b9dc491..ca1cec0db 100644
--- a/tests/Composer/Test/Package/Loader/ArrayLoaderTest.php
+++ b/tests/Composer/Test/Package/Loader/ArrayLoaderTest.php
@@ -148,7 +148,6 @@ class ArrayLoaderTest extends TestCase
     {
         $package = $this->loader->load($config);
         $dumper = new ArrayDumper;
-        $expectedConfig = $config;
         $expectedConfig = $this->fixConfigWhenLoadConfigIsFalse($config);
         $this->assertEquals($expectedConfig, $dumper->dump($package));
     }
diff --git a/tests/Composer/Test/Package/LockerTest.php b/tests/Composer/Test/Package/LockerTest.php
index c20c21466..bb8eaabde 100644
--- a/tests/Composer/Test/Package/LockerTest.php
+++ b/tests/Composer/Test/Package/LockerTest.php
@@ -24,7 +24,6 @@ class LockerTest extends TestCase
         $locker = new Locker(
             new NullIO,
             $json,
-            $this->createRepositoryManagerMock(),
             $this->createInstallationManagerMock(),
             $this->getJsonContent()
         );
@@ -44,10 +43,9 @@ class LockerTest extends TestCase
     public function testGetNotLockedPackages()
     {
         $json = $this->createJsonFileMock();
-        $repo = $this->createRepositoryManagerMock();
         $inst = $this->createInstallationManagerMock();
 
-        $locker = new Locker(new NullIO, $json, $repo, $inst, $this->getJsonContent());
+        $locker = new Locker(new NullIO, $json, $inst, $this->getJsonContent());
 
         $json
             ->expects($this->once())
@@ -62,10 +60,9 @@ class LockerTest extends TestCase
     public function testGetLockedPackages()
     {
         $json = $this->createJsonFileMock();
-        $repo = $this->createRepositoryManagerMock();
         $inst = $this->createInstallationManagerMock();
 
-        $locker = new Locker(new NullIO, $json, $repo, $inst, $this->getJsonContent());
+        $locker = new Locker(new NullIO, $json, $inst, $this->getJsonContent());
 
         $json
             ->expects($this->once())
@@ -89,11 +86,10 @@ class LockerTest extends TestCase
     public function testSetLockData()
     {
         $json = $this->createJsonFileMock();
-        $repo = $this->createRepositoryManagerMock();
         $inst = $this->createInstallationManagerMock();
 
         $jsonContent = $this->getJsonContent() . '  ';
-        $locker = new Locker(new NullIO, $json, $repo, $inst, $jsonContent);
+        $locker = new Locker(new NullIO, $json, $inst, $jsonContent);
 
         $package1 = $this->createPackageMock();
         $package2 = $this->createPackageMock();
@@ -162,10 +158,9 @@ class LockerTest extends TestCase
     public function testLockBadPackages()
     {
         $json = $this->createJsonFileMock();
-        $repo = $this->createRepositoryManagerMock();
         $inst = $this->createInstallationManagerMock();
 
-        $locker = new Locker(new NullIO, $json, $repo, $inst, $this->getJsonContent());
+        $locker = new Locker(new NullIO, $json, $inst, $this->getJsonContent());
 
         $package1 = $this->createPackageMock();
         $package1
@@ -181,11 +176,10 @@ class LockerTest extends TestCase
     public function testIsFresh()
     {
         $json = $this->createJsonFileMock();
-        $repo = $this->createRepositoryManagerMock();
         $inst = $this->createInstallationManagerMock();
 
         $jsonContent = $this->getJsonContent();
-        $locker = new Locker(new NullIO, $json, $repo, $inst, $jsonContent);
+        $locker = new Locker(new NullIO, $json, $inst, $jsonContent);
 
         $json
             ->expects($this->once())
@@ -198,10 +192,9 @@ class LockerTest extends TestCase
     public function testIsFreshFalse()
     {
         $json = $this->createJsonFileMock();
-        $repo = $this->createRepositoryManagerMock();
         $inst = $this->createInstallationManagerMock();
 
-        $locker = new Locker(new NullIO, $json, $repo, $inst, $this->getJsonContent());
+        $locker = new Locker(new NullIO, $json, $inst, $this->getJsonContent());
 
         $json
             ->expects($this->once())
@@ -214,11 +207,10 @@ class LockerTest extends TestCase
     public function testIsFreshWithContentHash()
     {
         $json = $this->createJsonFileMock();
-        $repo = $this->createRepositoryManagerMock();
         $inst = $this->createInstallationManagerMock();
 
         $jsonContent = $this->getJsonContent();
-        $locker = new Locker(new NullIO, $json, $repo, $inst, $jsonContent);
+        $locker = new Locker(new NullIO, $json, $inst, $jsonContent);
 
         $json
             ->expects($this->once())
@@ -231,11 +223,10 @@ class LockerTest extends TestCase
     public function testIsFreshWithContentHashAndNoHash()
     {
         $json = $this->createJsonFileMock();
-        $repo = $this->createRepositoryManagerMock();
         $inst = $this->createInstallationManagerMock();
 
         $jsonContent = $this->getJsonContent();
-        $locker = new Locker(new NullIO, $json, $repo, $inst, $jsonContent);
+        $locker = new Locker(new NullIO, $json, $inst, $jsonContent);
 
         $json
             ->expects($this->once())
@@ -248,10 +239,9 @@ class LockerTest extends TestCase
     public function testIsFreshFalseWithContentHash()
     {
         $json = $this->createJsonFileMock();
-        $repo = $this->createRepositoryManagerMock();
         $inst = $this->createInstallationManagerMock();
 
-        $locker = new Locker(new NullIO, $json, $repo, $inst, $this->getJsonContent());
+        $locker = new Locker(new NullIO, $json, $inst, $this->getJsonContent());
 
         $differentHash = md5($this->getJsonContent(array('name' => 'test2')));
 
@@ -270,19 +260,6 @@ class LockerTest extends TestCase
             ->getMock();
     }
 
-    private function createRepositoryManagerMock()
-    {
-        $mock = $this->getMockBuilder('Composer\Repository\RepositoryManager')
-            ->disableOriginalConstructor()
-            ->getMock();
-
-        $mock->expects($this->any())
-            ->method('getLocalRepository')
-            ->will($this->returnValue($this->getMockBuilder('Composer\Repository\ArrayRepository')->getMock()));
-
-        return $mock;
-    }
-
     private function createInstallationManagerMock()
     {
         $mock = $this->getMockBuilder('Composer\Installer\InstallationManager')
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v1/Installer/Plugin.php b/tests/Composer/Test/Plugin/Fixtures/plugin-v1/Installer/Plugin.php
index f80acd325..c757d4b09 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v1/Installer/Plugin.php
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v1/Installer/Plugin.php
@@ -12,5 +12,16 @@ class Plugin implements PluginInterface
 
     public function activate(Composer $composer, IOInterface $io)
     {
+        $io->write('activate v1');
+    }
+
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+        $io->write('deactivate v1');
+    }
+
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+        $io->write('uninstall v1');
     }
 }
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v2/Installer/Plugin2.php b/tests/Composer/Test/Plugin/Fixtures/plugin-v2/Installer/Plugin2.php
index db5a4462e..32090b66d 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v2/Installer/Plugin2.php
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v2/Installer/Plugin2.php
@@ -12,5 +12,16 @@ class Plugin2 implements PluginInterface
 
     public function activate(Composer $composer, IOInterface $io)
     {
+        $io->write('activate v2');
+    }
+
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+        $io->write('deactivate v2');
+    }
+
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+        $io->write('uninstall v2');
     }
 }
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v3/Installer/Plugin2.php b/tests/Composer/Test/Plugin/Fixtures/plugin-v3/Installer/Plugin2.php
index 861c1679b..034388162 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v3/Installer/Plugin2.php
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v3/Installer/Plugin2.php
@@ -12,5 +12,16 @@ class Plugin2 implements PluginInterface
 
     public function activate(Composer $composer, IOInterface $io)
     {
+        $io->write('activate v3');
+    }
+
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+        $io->write('deactivate v3');
+    }
+
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+        $io->write('uninstall v3');
     }
 }
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v4/Installer/Plugin1.php b/tests/Composer/Test/Plugin/Fixtures/plugin-v4/Installer/Plugin1.php
index 93bcabc98..2eaee6a3f 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v4/Installer/Plugin1.php
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v4/Installer/Plugin1.php
@@ -13,5 +13,16 @@ class Plugin1 implements PluginInterface
 
     public function activate(Composer $composer, IOInterface $io)
     {
+        $io->write('activate v4-plugin1');
+    }
+
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+        $io->write('deactivate v4-plugin1');
+    }
+
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+        $io->write('uninstall v4-plugin1');
     }
 }
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v4/Installer/Plugin2.php b/tests/Composer/Test/Plugin/Fixtures/plugin-v4/Installer/Plugin2.php
index d946deb89..3c5311a82 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v4/Installer/Plugin2.php
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v4/Installer/Plugin2.php
@@ -13,5 +13,16 @@ class Plugin2 implements PluginInterface
 
     public function activate(Composer $composer, IOInterface $io)
     {
+        $io->write('activate v4-plugin2');
+    }
+
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+        $io->write('deactivate v4-plugin2');
+    }
+
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+        $io->write('uninstall v4-plugin2');
     }
 }
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v5/Installer/Plugin5.php b/tests/Composer/Test/Plugin/Fixtures/plugin-v5/Installer/Plugin5.php
index a2ac37bc5..fb9f08a6d 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v5/Installer/Plugin5.php
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v5/Installer/Plugin5.php
@@ -10,5 +10,16 @@ class Plugin5 implements PluginInterface
 {
     public function activate(Composer $composer, IOInterface $io)
     {
+        $io->write('activate v5');
+    }
+
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+        $io->write('deactivate v5');
+    }
+
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+        $io->write('uninstall v5');
     }
 }
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v6/Installer/Plugin6.php b/tests/Composer/Test/Plugin/Fixtures/plugin-v6/Installer/Plugin6.php
index e46c0fcb0..acce1f972 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v6/Installer/Plugin6.php
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v6/Installer/Plugin6.php
@@ -10,5 +10,16 @@ class Plugin6 implements PluginInterface
 {
     public function activate(Composer $composer, IOInterface $io)
     {
+        $io->write('activate v6');
+    }
+
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+        $io->write('deactivate v6');
+    }
+
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+        $io->write('uninstall v6');
     }
 }
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v7/Installer/Plugin7.php b/tests/Composer/Test/Plugin/Fixtures/plugin-v7/Installer/Plugin7.php
index 5560a6047..84734ce3b 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v7/Installer/Plugin7.php
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v7/Installer/Plugin7.php
@@ -10,5 +10,16 @@ class Plugin7 implements PluginInterface
 {
     public function activate(Composer $composer, IOInterface $io)
     {
+        $io->write('activate v7');
+    }
+
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+        $io->write('deactivate v7');
+    }
+
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+        $io->write('uninstall v7');
     }
 }
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v8/Installer/Plugin8.php b/tests/Composer/Test/Plugin/Fixtures/plugin-v8/Installer/Plugin8.php
index 7e9a0aab1..4534e13ef 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v8/Installer/Plugin8.php
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v8/Installer/Plugin8.php
@@ -13,6 +13,17 @@ class Plugin8 implements PluginInterface, Capable
 
     public function activate(Composer $composer, IOInterface $io)
     {
+        $io->write('activate v8');
+    }
+
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+        $io->write('deactivate v8');
+    }
+
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+        $io->write('uninstall v8');
     }
 
     public function getCapabilities()
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v9/Installer/Plugin.php b/tests/Composer/Test/Plugin/Fixtures/plugin-v9/Installer/Plugin.php
index 74e1beb8b..870f11cd1 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v9/Installer/Plugin.php
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v9/Installer/Plugin.php
@@ -14,5 +14,16 @@ class Plugin implements PluginInterface
 
     public function activate(Composer $composer, IOInterface $io)
     {
+        $io->write('activate v9');
+    }
+
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+        $io->write('deactivate v9');
+    }
+
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+        $io->write('uninstall v9');
     }
 }
diff --git a/tests/Composer/Test/Plugin/PluginInstallerTest.php b/tests/Composer/Test/Plugin/PluginInstallerTest.php
index 633c5ab18..bd83ce16f 100644
--- a/tests/Composer/Test/Plugin/PluginInstallerTest.php
+++ b/tests/Composer/Test/Plugin/PluginInstallerTest.php
@@ -19,6 +19,9 @@ use Composer\Package\CompletePackage;
 use Composer\Package\Loader\JsonLoader;
 use Composer\Package\Loader\ArrayLoader;
 use Composer\Plugin\PluginManager;
+use Symfony\Component\Console\Output\OutputInterface;
+use Composer\IO\BufferIO;
+use Composer\EventDispatcher\EventDispatcher;
 use Composer\Autoload\AutoloadGenerator;
 use Composer\Test\TestCase;
 use Composer\Util\Filesystem;
@@ -96,7 +99,7 @@ class PluginInstallerTest extends TestCase
                 return __DIR__.'/Fixtures/'.$package->getPrettyName();
             }));
 
-        $this->io = $this->getMockBuilder('Composer\IO\IOInterface')->getMock();
+        $this->io = new BufferIO();
 
         $dispatcher = $this->getMockBuilder('Composer\EventDispatcher\EventDispatcher')->disableOriginalConstructor()->getMock();
         $this->autoloadGenerator = new AutoloadGenerator($dispatcher);
@@ -108,6 +111,7 @@ class PluginInstallerTest extends TestCase
         $this->composer->setRepositoryManager($rm);
         $this->composer->setInstallationManager($im);
         $this->composer->setAutoloadGenerator($this->autoloadGenerator);
+        $this->composer->setEventDispatcher(new EventDispatcher($this->composer, $this->io));
 
         $this->pm = new PluginManager($this->io, $this->composer);
         $this->composer->setPluginManager($this->pm);
@@ -140,6 +144,7 @@ class PluginInstallerTest extends TestCase
 
         $plugins = $this->pm->getPlugins();
         $this->assertEquals('installer-v1', $plugins[0]->version);
+        $this->assertEquals('activate v1'.PHP_EOL, $this->io->getOutput());
     }
 
     public function testInstallMultiplePlugins()
@@ -158,6 +163,7 @@ class PluginInstallerTest extends TestCase
         $this->assertEquals('installer-v4', $plugins[0]->version);
         $this->assertEquals('plugin2', $plugins[1]->name);
         $this->assertEquals('installer-v4', $plugins[1]->version);
+        $this->assertEquals('activate v4-plugin1'.PHP_EOL.'activate v4-plugin2'.PHP_EOL, $this->io->getOutput());
     }
 
     public function testUpgradeWithNewClassName()
@@ -176,7 +182,29 @@ class PluginInstallerTest extends TestCase
         $installer->update($this->repository, $this->packages[0], $this->packages[1]);
 
         $plugins = $this->pm->getPlugins();
+        $this->assertCount(1, $plugins);
         $this->assertEquals('installer-v2', $plugins[1]->version);
+        $this->assertEquals('activate v1'.PHP_EOL.'deactivate v1'.PHP_EOL.'activate v2'.PHP_EOL, $this->io->getOutput());
+    }
+
+    public function testUninstall()
+    {
+        $this->repository
+            ->expects($this->once())
+            ->method('getPackages')
+            ->will($this->returnValue(array($this->packages[0])));
+        $this->repository
+            ->expects($this->exactly(1))
+            ->method('hasPackage')
+            ->will($this->onConsecutiveCalls(true, false));
+        $installer = new PluginInstaller($this->io, $this->composer);
+        $this->pm->loadInstalledPlugins();
+
+        $installer->uninstall($this->repository, $this->packages[0]);
+
+        $plugins = $this->pm->getPlugins();
+        $this->assertCount(0, $plugins);
+        $this->assertEquals('activate v1'.PHP_EOL.'deactivate v1'.PHP_EOL.'uninstall v1'.PHP_EOL, $this->io->getOutput());
     }
 
     public function testUpgradeWithSameClassName()
@@ -196,6 +224,7 @@ class PluginInstallerTest extends TestCase
 
         $plugins = $this->pm->getPlugins();
         $this->assertEquals('installer-v3', $plugins[1]->version);
+        $this->assertEquals('activate v2'.PHP_EOL.'deactivate v2'.PHP_EOL.'activate v3'.PHP_EOL, $this->io->getOutput());
     }
 
     public function testRegisterPluginOnlyOneTime()
@@ -213,6 +242,7 @@ class PluginInstallerTest extends TestCase
         $plugins = $this->pm->getPlugins();
         $this->assertCount(1, $plugins);
         $this->assertEquals('installer-v1', $plugins[0]->version);
+        $this->assertEquals('activate v1'.PHP_EOL, $this->io->getOutput());
     }
 
     /**
diff --git a/tests/Composer/Test/Repository/ComposerRepositoryTest.php b/tests/Composer/Test/Repository/ComposerRepositoryTest.php
index 47df3a443..22a58cf4f 100644
--- a/tests/Composer/Test/Repository/ComposerRepositoryTest.php
+++ b/tests/Composer/Test/Repository/ComposerRepositoryTest.php
@@ -227,7 +227,9 @@ class ComposerRepositoryTest extends TestCase
         $repository = new ComposerRepository(
             array('url' => $repositoryUrl),
             new NullIO(),
-            FactoryMock::createConfig()
+            FactoryMock::createConfig(),
+            $this->getMockBuilder('Composer\Util\HttpDownloader')->disableOriginalConstructor()->getMock(),
+            $this->getMockBuilder('Composer\EventDispatcher\EventDispatcher')->disableOriginalConstructor()->getMock()
         );
 
         $object = new \ReflectionObject($repository);
diff --git a/tests/Composer/Test/Repository/FilesystemRepositoryTest.php b/tests/Composer/Test/Repository/FilesystemRepositoryTest.php
index be8b0d0a9..97747ebc5 100644
--- a/tests/Composer/Test/Repository/FilesystemRepositoryTest.php
+++ b/tests/Composer/Test/Repository/FilesystemRepositoryTest.php
@@ -82,11 +82,21 @@ class FilesystemRepositoryTest extends TestCase
         $json = $this->createJsonFileMock();
 
         $repository = new FilesystemRepository($json);
+        $im = $this->getMockBuilder('Composer\Installer\InstallationManager')
+            ->disableOriginalConstructor()
+            ->getMock();
+        $im->expects($this->once())
+            ->method('getInstallPath')
+            ->will($this->returnValue('/foo/bar/vendor/woop/woop'));
 
         $json
             ->expects($this->once())
             ->method('read')
             ->will($this->returnValue(array()));
+        $json
+            ->expects($this->once())
+            ->method('getPath')
+            ->will($this->returnValue('/foo/bar/vendor/composer/installed.json'));
         $json
             ->expects($this->once())
             ->method('exists')
@@ -95,11 +105,12 @@ class FilesystemRepositoryTest extends TestCase
             ->expects($this->once())
             ->method('write')
             ->with(array(
-                array('name' => 'mypkg', 'type' => 'library', 'version' => '0.1.10', 'version_normalized' => '0.1.10.0'),
+                'packages' => array(array('name' => 'mypkg', 'type' => 'library', 'version' => '0.1.10', 'version_normalized' => '0.1.10.0', 'install-path' => '../woop/woop')),
+                'dev' => true,
             ));
 
         $repository->addPackage($this->getPackage('mypkg', '0.1.10'));
-        $repository->write();
+        $repository->write(true, $im);
     }
 
     private function createJsonFileMock()
diff --git a/tests/Composer/Test/Repository/Vcs/FossilDriverTest.php b/tests/Composer/Test/Repository/Vcs/FossilDriverTest.php
index cbb4342e9..f39a3b8f7 100644
--- a/tests/Composer/Test/Repository/Vcs/FossilDriverTest.php
+++ b/tests/Composer/Test/Repository/Vcs/FossilDriverTest.php
@@ -40,15 +40,6 @@ class FossilDriverTest extends TestCase
         $fs->removeDirectory($this->home);
     }
 
-    private function getCmd($cmd)
-    {
-        if (Platform::isWindows()) {
-            return strtr($cmd, "'", '"');
-        }
-
-        return $cmd;
-    }
-
     public static function supportProvider()
     {
         return array(
diff --git a/tests/Composer/Test/Repository/Vcs/SvnDriverTest.php b/tests/Composer/Test/Repository/Vcs/SvnDriverTest.php
index 946c198f2..b43cbbc2a 100644
--- a/tests/Composer/Test/Repository/Vcs/SvnDriverTest.php
+++ b/tests/Composer/Test/Repository/Vcs/SvnDriverTest.php
@@ -71,15 +71,6 @@ class SvnDriverTest extends TestCase
         $svn->initialize();
     }
 
-    private function getCmd($cmd)
-    {
-        if (Platform::isWindows()) {
-            return strtr($cmd, "'", '"');
-        }
-
-        return $cmd;
-    }
-
     public static function supportProvider()
     {
         return array(
diff --git a/tests/Composer/Test/Script/EventTest.php b/tests/Composer/Test/Script/EventTest.php
new file mode 100644
index 000000000..b7c8cd9ff
--- /dev/null
+++ b/tests/Composer/Test/Script/EventTest.php
@@ -0,0 +1,80 @@
+<?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\Script;
+
+use Composer\Composer;
+use Composer\Config;
+use Composer\Script\Event;
+use Composer\Test\TestCase;
+
+class EventTest extends TestCase
+{
+    public function testEventSetsOriginatingEvent()
+    {
+        $io = $this->getMockBuilder('Composer\IO\IOInterface')->getMock();
+        $composer = $this->createComposerInstance();
+
+        $originatingEvent = new \Composer\EventDispatcher\Event('originatingEvent');
+
+        $scriptEvent = new Event('test', $composer, $io, true);
+
+        $this->assertNull(
+            $scriptEvent->getOriginatingEvent(),
+            'originatingEvent is initialized as null'
+        );
+
+        $scriptEvent->setOriginatingEvent($originatingEvent);
+
+        $this->assertSame(
+            $originatingEvent,
+            $scriptEvent->getOriginatingEvent(),
+            'getOriginatingEvent() SHOULD return test event'
+        );
+    }
+
+    public function testEventCalculatesNestedOriginatingEvent()
+    {
+        $io = $this->getMockBuilder('Composer\IO\IOInterface')->getMock();
+        $composer = $this->createComposerInstance();
+
+        $originatingEvent = new \Composer\EventDispatcher\Event('upperOriginatingEvent');
+        $intermediateEvent = new Event('intermediate', $composer, $io, true);
+        $intermediateEvent->setOriginatingEvent($originatingEvent);
+
+        $scriptEvent = new Event('test', $composer, $io, true);
+        $scriptEvent->setOriginatingEvent($intermediateEvent);
+
+        $this->assertNotSame(
+            $intermediateEvent,
+            $scriptEvent->getOriginatingEvent(),
+            'getOriginatingEvent() SHOULD NOT return intermediate events'
+        );
+
+        $this->assertSame(
+            $originatingEvent,
+            $scriptEvent->getOriginatingEvent(),
+            'getOriginatingEvent() SHOULD return upper-most event'
+        );
+    }
+
+    private function createComposerInstance()
+    {
+        $composer = new Composer;
+        $config = new Config;
+        $composer->setConfig($config);
+        $package = $this->getMockBuilder('Composer\Package\RootPackageInterface')->getMock();
+        $composer->setPackage($package);
+
+        return $composer;
+    }
+}
diff --git a/tests/Composer/Test/Util/Fixtures/Zip/empty.zip b/tests/Composer/Test/Util/Fixtures/Zip/empty.zip
new file mode 100644
index 000000000..15cb0ecb3
Binary files /dev/null and b/tests/Composer/Test/Util/Fixtures/Zip/empty.zip differ
diff --git a/tests/Composer/Test/Util/Fixtures/Zip/folder.zip b/tests/Composer/Test/Util/Fixtures/Zip/folder.zip
new file mode 100644
index 000000000..72b17b542
Binary files /dev/null and b/tests/Composer/Test/Util/Fixtures/Zip/folder.zip differ
diff --git a/tests/Composer/Test/Util/Fixtures/Zip/multiple.zip b/tests/Composer/Test/Util/Fixtures/Zip/multiple.zip
new file mode 100644
index 000000000..db8c50302
Binary files /dev/null and b/tests/Composer/Test/Util/Fixtures/Zip/multiple.zip differ
diff --git a/tests/Composer/Test/Util/Fixtures/Zip/nojson.zip b/tests/Composer/Test/Util/Fixtures/Zip/nojson.zip
new file mode 100644
index 000000000..e536b956c
Binary files /dev/null and b/tests/Composer/Test/Util/Fixtures/Zip/nojson.zip differ
diff --git a/tests/Composer/Test/Util/Fixtures/Zip/root.zip b/tests/Composer/Test/Util/Fixtures/Zip/root.zip
new file mode 100644
index 000000000..fd08f4d34
Binary files /dev/null and b/tests/Composer/Test/Util/Fixtures/Zip/root.zip differ
diff --git a/tests/Composer/Test/Util/Fixtures/Zip/subfolder.zip b/tests/Composer/Test/Util/Fixtures/Zip/subfolder.zip
new file mode 100644
index 000000000..93060bea2
Binary files /dev/null and b/tests/Composer/Test/Util/Fixtures/Zip/subfolder.zip differ
diff --git a/tests/Composer/Test/Util/GitHubTest.php b/tests/Composer/Test/Util/GitHubTest.php
index 1893486e0..4e21d5f77 100644
--- a/tests/Composer/Test/Util/GitHubTest.php
+++ b/tests/Composer/Test/Util/GitHubTest.php
@@ -24,12 +24,9 @@ use RecursiveIteratorIterator;
  */
 class GitHubTest extends TestCase
 {
-    private $username = 'username';
     private $password = 'password';
-    private $authcode = 'authcode';
     private $message = 'mymessage';
     private $origin = 'github.com';
-    private $token = 'githubtoken';
 
     public function testUsernamePasswordAuthenticationFlow()
     {
diff --git a/tests/Composer/Test/Util/GitLabTest.php b/tests/Composer/Test/Util/GitLabTest.php
index 611b25256..6037e7a0b 100644
--- a/tests/Composer/Test/Util/GitLabTest.php
+++ b/tests/Composer/Test/Util/GitLabTest.php
@@ -24,7 +24,6 @@ class GitLabTest extends TestCase
 {
     private $username = 'username';
     private $password = 'password';
-    private $authcode = 'authcode';
     private $message = 'mymessage';
     private $origin = 'gitlab.com';
     private $token = 'gitlabtoken';
diff --git a/tests/Composer/Test/Util/ZipTest.php b/tests/Composer/Test/Util/ZipTest.php
new file mode 100644
index 000000000..c47373274
--- /dev/null
+++ b/tests/Composer/Test/Util/ZipTest.php
@@ -0,0 +1,117 @@
+<?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\Util;
+
+use Composer\Util\Zip;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @author Andreas Schempp <andreas.schempp@terminal42.ch>
+ */
+class ZipTest extends TestCase
+{
+    public function testThrowsExceptionIfZipExcentionIsNotLoaded()
+    {
+        if (extension_loaded('zip')) {
+            $this->markTestSkipped('The PHP zip extension is loaded.');
+        }
+
+        $this->setExpectedException('\RuntimeException', 'The Zip Util requires PHP\'s zip extension');
+
+        Zip::getComposerJson('');
+    }
+
+    public function testReturnsNullifTheZipIsNotFound()
+    {
+        if (!extension_loaded('zip')) {
+            $this->markTestSkipped('The PHP zip extension is not loaded.');
+            return;
+        }
+
+        $result = Zip::getComposerJson(__DIR__.'/Fixtures/Zip/invalid.zip');
+
+        $this->assertNull($result);
+    }
+
+    public function testReturnsNullIfTheZipIsEmpty()
+    {
+        if (!extension_loaded('zip')) {
+            $this->markTestSkipped('The PHP zip extension is not loaded.');
+            return;
+        }
+
+        $result = Zip::getComposerJson(__DIR__.'/Fixtures/Zip/empty.zip');
+
+        $this->assertNull($result);
+    }
+
+    public function testReturnsNullIfTheZipHasNoComposerJson()
+    {
+        if (!extension_loaded('zip')) {
+            $this->markTestSkipped('The PHP zip extension is not loaded.');
+            return;
+        }
+
+        $result = Zip::getComposerJson(__DIR__.'/Fixtures/Zip/nojson.zip');
+
+        $this->assertNull($result);
+    }
+
+    public function testReturnsNullIfTheComposerJsonIsInASubSubfolder()
+    {
+        if (!extension_loaded('zip')) {
+            $this->markTestSkipped('The PHP zip extension is not loaded.');
+            return;
+        }
+
+        $result = Zip::getComposerJson(__DIR__.'/Fixtures/Zip/subfolder.zip');
+
+        $this->assertNull($result);
+    }
+
+    public function testReturnsComposerJsonInZipRoot()
+    {
+        if (!extension_loaded('zip')) {
+            $this->markTestSkipped('The PHP zip extension is not loaded.');
+            return;
+        }
+
+        $result = Zip::getComposerJson(__DIR__.'/Fixtures/Zip/root.zip');
+
+        $this->assertEquals("{\n    \"name\": \"foo/bar\"\n}\n", $result);
+    }
+
+    public function testReturnsComposerJsonInFirstFolder()
+    {
+        if (!extension_loaded('zip')) {
+            $this->markTestSkipped('The PHP zip extension is not loaded.');
+            return;
+        }
+
+        $result = Zip::getComposerJson(__DIR__.'/Fixtures/Zip/folder.zip');
+
+        $this->assertEquals("{\n    \"name\": \"foo/bar\"\n}\n", $result);
+    }
+
+    public function testReturnsRootComposerJsonAndSkipsSubfolders()
+    {
+        if (!extension_loaded('zip')) {
+            $this->markTestSkipped('The PHP zip extension is not loaded.');
+            return;
+        }
+
+        $result = Zip::getComposerJson(__DIR__.'/Fixtures/Zip/multiple.zip');
+
+        $this->assertEquals("{\n    \"name\": \"foo/bar\"\n}\n", $result);
+    }
+}