Merge pull request #25360 from nextcloud/fix/update-autoloaders

Update all composer autoloader files

52 files changed, 858 insertions, 26 deletions

diff --git a/apps/accessibility/composer/composer/ClassLoader.php b/apps/accessibility/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/accessibility/composer/composer/ClassLoader.php
+++ b/apps/accessibility/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/accessibility/composer/composer/autoload_real.php b/apps/accessibility/composer/composer/autoload_real.php
index 49095f94dad..86277d610bf 100644
--- a/apps/accessibility/composer/composer/autoload_real.php
+++ b/apps/accessibility/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitAccessibility
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitAccessibility', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitAccessibility', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/admin_audit/composer/composer/ClassLoader.php b/apps/admin_audit/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/admin_audit/composer/composer/ClassLoader.php
+++ b/apps/admin_audit/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/admin_audit/composer/composer/autoload_real.php b/apps/admin_audit/composer/composer/autoload_real.php
index b6c30f2c838..5c3d4551dd6 100644
--- a/apps/admin_audit/composer/composer/autoload_real.php
+++ b/apps/admin_audit/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitAdminAudit
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitAdminAudit', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitAdminAudit', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/cloud_federation_api/composer/composer/ClassLoader.php b/apps/cloud_federation_api/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/cloud_federation_api/composer/composer/ClassLoader.php
+++ b/apps/cloud_federation_api/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/cloud_federation_api/composer/composer/autoload_real.php b/apps/cloud_federation_api/composer/composer/autoload_real.php
index 81afd5039a7..f0ee7acb591 100644
--- a/apps/cloud_federation_api/composer/composer/autoload_real.php
+++ b/apps/cloud_federation_api/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitCloudFederationAPI
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitCloudFederationAPI', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitCloudFederationAPI', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/comments/composer/composer/ClassLoader.php b/apps/comments/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/comments/composer/composer/ClassLoader.php
+++ b/apps/comments/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/comments/composer/composer/autoload_real.php b/apps/comments/composer/composer/autoload_real.php
index 3c1d559e47a..8b8855d7d4f 100644
--- a/apps/comments/composer/composer/autoload_real.php
+++ b/apps/comments/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitComments
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitComments', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitComments', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/contactsinteraction/composer/composer/ClassLoader.php b/apps/contactsinteraction/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/contactsinteraction/composer/composer/ClassLoader.php
+++ b/apps/contactsinteraction/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/contactsinteraction/composer/composer/autoload_real.php b/apps/contactsinteraction/composer/composer/autoload_real.php
index 0b71a9a3ee7..d0f0da36ef3 100644
--- a/apps/contactsinteraction/composer/composer/autoload_real.php
+++ b/apps/contactsinteraction/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitContactsInteraction
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitContactsInteraction', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitContactsInteraction', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/dav/composer/composer/ClassLoader.php b/apps/dav/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/dav/composer/composer/ClassLoader.php
+++ b/apps/dav/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/dav/composer/composer/autoload_real.php b/apps/dav/composer/composer/autoload_real.php
index da247127bcf..80611c8f531 100644
--- a/apps/dav/composer/composer/autoload_real.php
+++ b/apps/dav/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitDAV
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitDAV', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitDAV', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/encryption/composer/composer/ClassLoader.php b/apps/encryption/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/encryption/composer/composer/ClassLoader.php
+++ b/apps/encryption/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/encryption/composer/composer/autoload_real.php b/apps/encryption/composer/composer/autoload_real.php
index 61038bda5d0..81daae1bc0d 100644
--- a/apps/encryption/composer/composer/autoload_real.php
+++ b/apps/encryption/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitEncryption
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitEncryption', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitEncryption', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/federatedfilesharing/composer/composer/ClassLoader.php b/apps/federatedfilesharing/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/federatedfilesharing/composer/composer/ClassLoader.php
+++ b/apps/federatedfilesharing/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/federatedfilesharing/composer/composer/autoload_real.php b/apps/federatedfilesharing/composer/composer/autoload_real.php
index 1c713aa4e0a..25a7e49d09f 100644
--- a/apps/federatedfilesharing/composer/composer/autoload_real.php
+++ b/apps/federatedfilesharing/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitFederatedFileSharing
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitFederatedFileSharing', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitFederatedFileSharing', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/federation/composer/composer/ClassLoader.php b/apps/federation/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/federation/composer/composer/ClassLoader.php
+++ b/apps/federation/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/federation/composer/composer/autoload_real.php b/apps/federation/composer/composer/autoload_real.php
index e765b208882..fed3f44342e 100644
--- a/apps/federation/composer/composer/autoload_real.php
+++ b/apps/federation/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitFederation
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitFederation', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitFederation', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/files/composer/composer/ClassLoader.php b/apps/files/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/files/composer/composer/ClassLoader.php
+++ b/apps/files/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/files/composer/composer/autoload_real.php b/apps/files/composer/composer/autoload_real.php
index e95b5b4e539..462094eaafc 100644
--- a/apps/files/composer/composer/autoload_real.php
+++ b/apps/files/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitFiles
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitFiles', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitFiles', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/files_sharing/composer/composer/ClassLoader.php b/apps/files_sharing/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/files_sharing/composer/composer/ClassLoader.php
+++ b/apps/files_sharing/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/files_sharing/composer/composer/autoload_real.php b/apps/files_sharing/composer/composer/autoload_real.php
index 089fed2e7e6..0b3bf55f31e 100644
--- a/apps/files_sharing/composer/composer/autoload_real.php
+++ b/apps/files_sharing/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitFiles_Sharing
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitFiles_Sharing', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitFiles_Sharing', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/files_trashbin/composer/composer/ClassLoader.php b/apps/files_trashbin/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/files_trashbin/composer/composer/ClassLoader.php
+++ b/apps/files_trashbin/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/files_trashbin/composer/composer/autoload_real.php b/apps/files_trashbin/composer/composer/autoload_real.php
index fb01e59f31f..35ef7fdcfa7 100644
--- a/apps/files_trashbin/composer/composer/autoload_real.php
+++ b/apps/files_trashbin/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitFiles_Trashbin
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitFiles_Trashbin', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitFiles_Trashbin', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/files_versions/composer/composer/ClassLoader.php b/apps/files_versions/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/files_versions/composer/composer/ClassLoader.php
+++ b/apps/files_versions/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/files_versions/composer/composer/autoload_real.php b/apps/files_versions/composer/composer/autoload_real.php
index 78a97e23561..7048e07160a 100644
--- a/apps/files_versions/composer/composer/autoload_real.php
+++ b/apps/files_versions/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitFiles_Versions
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitFiles_Versions', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitFiles_Versions', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/lookup_server_connector/composer/composer/ClassLoader.php b/apps/lookup_server_connector/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/lookup_server_connector/composer/composer/ClassLoader.php
+++ b/apps/lookup_server_connector/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/lookup_server_connector/composer/composer/autoload_real.php b/apps/lookup_server_connector/composer/composer/autoload_real.php
index a93aa564257..3f635cf99aa 100644
--- a/apps/lookup_server_connector/composer/composer/autoload_real.php
+++ b/apps/lookup_server_connector/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitLookupServerConnector
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitLookupServerConnector', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitLookupServerConnector', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/oauth2/composer/composer/ClassLoader.php b/apps/oauth2/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/oauth2/composer/composer/ClassLoader.php
+++ b/apps/oauth2/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/oauth2/composer/composer/autoload_real.php b/apps/oauth2/composer/composer/autoload_real.php
index 783fea38c8c..7a5c7fdcaf5 100644
--- a/apps/oauth2/composer/composer/autoload_real.php
+++ b/apps/oauth2/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitOAuth2
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitOAuth2', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitOAuth2', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/provisioning_api/composer/composer/ClassLoader.php b/apps/provisioning_api/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/provisioning_api/composer/composer/ClassLoader.php
+++ b/apps/provisioning_api/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/provisioning_api/composer/composer/autoload_real.php b/apps/provisioning_api/composer/composer/autoload_real.php
index 58c1c790749..f5169309306 100644
--- a/apps/provisioning_api/composer/composer/autoload_real.php
+++ b/apps/provisioning_api/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitProvisioning_API
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitProvisioning_API', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitProvisioning_API', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/settings/composer/composer/ClassLoader.php b/apps/settings/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/settings/composer/composer/ClassLoader.php
+++ b/apps/settings/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/settings/composer/composer/autoload_real.php b/apps/settings/composer/composer/autoload_real.php
index 609a409b5fc..11f0c1cdd44 100644
--- a/apps/settings/composer/composer/autoload_real.php
+++ b/apps/settings/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitSettings
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitSettings', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitSettings', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/sharebymail/composer/composer/ClassLoader.php b/apps/sharebymail/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/sharebymail/composer/composer/ClassLoader.php
+++ b/apps/sharebymail/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/sharebymail/composer/composer/autoload_real.php b/apps/sharebymail/composer/composer/autoload_real.php
index 0f2a8443592..87493707619 100644
--- a/apps/sharebymail/composer/composer/autoload_real.php
+++ b/apps/sharebymail/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitShareByMail
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitShareByMail', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitShareByMail', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/systemtags/composer/composer/ClassLoader.php b/apps/systemtags/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/systemtags/composer/composer/ClassLoader.php
+++ b/apps/systemtags/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/systemtags/composer/composer/autoload_real.php b/apps/systemtags/composer/composer/autoload_real.php
index 1a4f82387ab..81bbfbcd09c 100644
--- a/apps/systemtags/composer/composer/autoload_real.php
+++ b/apps/systemtags/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitSystemTags
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitSystemTags', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitSystemTags', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/testing/composer/composer/ClassLoader.php b/apps/testing/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/testing/composer/composer/ClassLoader.php
+++ b/apps/testing/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/testing/composer/composer/autoload_real.php b/apps/testing/composer/composer/autoload_real.php
index 6807a3a688e..220aa05db64 100644
--- a/apps/testing/composer/composer/autoload_real.php
+++ b/apps/testing/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitTesting
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitTesting', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitTesting', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/twofactor_backupcodes/composer/composer/ClassLoader.php b/apps/twofactor_backupcodes/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/twofactor_backupcodes/composer/composer/ClassLoader.php
+++ b/apps/twofactor_backupcodes/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/twofactor_backupcodes/composer/composer/autoload_real.php b/apps/twofactor_backupcodes/composer/composer/autoload_real.php
index 8a8417a3df1..54580be4664 100644
--- a/apps/twofactor_backupcodes/composer/composer/autoload_real.php
+++ b/apps/twofactor_backupcodes/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitTwoFactorBackupCodes
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitTwoFactorBackupCodes', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitTwoFactorBackupCodes', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/updatenotification/composer/composer/ClassLoader.php b/apps/updatenotification/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/updatenotification/composer/composer/ClassLoader.php
+++ b/apps/updatenotification/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/updatenotification/composer/composer/autoload_real.php b/apps/updatenotification/composer/composer/autoload_real.php
index 4943ba8dde6..92169a76d4c 100644
--- a/apps/updatenotification/composer/composer/autoload_real.php
+++ b/apps/updatenotification/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitUpdateNotification
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitUpdateNotification', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitUpdateNotification', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/user_ldap/composer/composer/ClassLoader.php b/apps/user_ldap/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/user_ldap/composer/composer/ClassLoader.php
+++ b/apps/user_ldap/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/user_ldap/composer/composer/autoload_real.php b/apps/user_ldap/composer/composer/autoload_real.php
index c7028787382..7cfd2b52370 100644
--- a/apps/user_ldap/composer/composer/autoload_real.php
+++ b/apps/user_ldap/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitUser_LDAP
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitUser_LDAP', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitUser_LDAP', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/user_status/composer/composer/ClassLoader.php b/apps/user_status/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/user_status/composer/composer/ClassLoader.php
+++ b/apps/user_status/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/user_status/composer/composer/autoload_real.php b/apps/user_status/composer/composer/autoload_real.php
index 3ae7e262e56..987d1dab4e6 100644
--- a/apps/user_status/composer/composer/autoload_real.php
+++ b/apps/user_status/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitUserStatus
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitUserStatus', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitUserStatus', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/apps/workflowengine/composer/composer/ClassLoader.php b/apps/workflowengine/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/apps/workflowengine/composer/composer/ClassLoader.php
+++ b/apps/workflowengine/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/apps/workflowengine/composer/composer/autoload_real.php b/apps/workflowengine/composer/composer/autoload_real.php
index 4858f945c65..6c14ae97018 100644
--- a/apps/workflowengine/composer/composer/autoload_real.php
+++ b/apps/workflowengine/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInitWorkflowEngine
         }
 
         spl_autoload_register(array('ComposerAutoloaderInitWorkflowEngine', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInitWorkflowEngine', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());
diff --git a/lib/composer/composer/ClassLoader.php b/lib/composer/composer/ClassLoader.php
index 1a58957d25d..4d989a212c9 100644
--- a/lib/composer/composer/ClassLoader.php
+++ b/lib/composer/composer/ClassLoader.php
@@ -42,6 +42,8 @@ namespace Composer\Autoload;
  */
 class ClassLoader
 {
+    private $vendorDir;
+
     // PSR-4
     private $prefixLengthsPsr4 = array();
     private $prefixDirsPsr4 = array();
@@ -57,6 +59,13 @@ class ClassLoader
     private $missingClasses = array();
     private $apcuPrefix;
 
+    private static $registeredLoaders = array();
+
+    public function __construct($vendorDir = null)
+    {
+        $this->vendorDir = $vendorDir;
+    }
+
     public function getPrefixes()
     {
         if (!empty($this->prefixesPsr0)) {
@@ -300,6 +309,15 @@ class ClassLoader
     public function register($prepend = false)
     {
         spl_autoload_register(array($this, 'loadClass'), true, $prepend);
+
+        if (null === $this->vendorDir) {
+            //no-op
+        } elseif ($prepend) {
+            self::$registeredLoaders = array($this->vendorDir => $this) + self::$registeredLoaders;
+        } else {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+            self::$registeredLoaders[$this->vendorDir] = $this;
+        }
     }
 
     /**
@@ -308,6 +326,10 @@ class ClassLoader
     public function unregister()
     {
         spl_autoload_unregister(array($this, 'loadClass'));
+
+        if (null !== $this->vendorDir) {
+            unset(self::$registeredLoaders[$this->vendorDir]);
+        }
     }
 
     /**
@@ -367,6 +389,16 @@ class ClassLoader
         return $file;
     }
 
+    /**
+     * Returns the currently registered loaders indexed by their corresponding vendor directories.
+     *
+     * @return self[]
+     */
+    public static function getRegisteredLoaders()
+    {
+        return self::$registeredLoaders;
+    }
+
     private function findFileWithExtension($class, $ext)
     {
         // PSR-4 lookup
diff --git a/lib/composer/composer/autoload_real.php b/lib/composer/composer/autoload_real.php
index fbda63683d5..a5748c7a891 100644
--- a/lib/composer/composer/autoload_real.php
+++ b/lib/composer/composer/autoload_real.php
@@ -23,7 +23,7 @@ class ComposerAutoloaderInit53792487c5a8370acc0b06b1a864ff4c
         }
 
         spl_autoload_register(array('ComposerAutoloaderInit53792487c5a8370acc0b06b1a864ff4c', 'loadClassLoader'), true, true);
-        self::$loader = $loader = new \Composer\Autoload\ClassLoader();
+        self::$loader = $loader = new \Composer\Autoload\ClassLoader(\dirname(\dirname(__FILE__)));
         spl_autoload_unregister(array('ComposerAutoloaderInit53792487c5a8370acc0b06b1a864ff4c', 'loadClassLoader'));
 
         $useStaticLoader = PHP_VERSION_ID >= 50600 && !defined('HHVM_VERSION') && (!function_exists('zend_loader_file_encoded') || !zend_loader_file_encoded());