Fix tests and edge case

src/Composer/Plugin/PluginManager.php

@@ -175,7 +175,8 @@ class PluginManager
         $localRepo = $this->composer->getRepositoryManager()->getLocalRepository();
         $globalRepo = $this->globalComposer ? $this->globalComposer->getRepositoryManager()->getLocalRepository() : null;
 
-        $rootPackageRepo = new RootPackageRepository($this->composer->getPackage());
+        $rootPackage = clone $this->composer->getPackage();
+        $rootPackageRepo = new RootPackageRepository($rootPackage);
         $installedRepo = new InstalledRepository(array($localRepo, $rootPackageRepo));
         if ($globalRepo) {
             $installedRepo->addRepository($globalRepo);
@@ -187,7 +188,7 @@ class PluginManager
         $generator = $this->composer->getAutoloadGenerator();
         $autoloads = array();
         foreach ($autoloadPackages as $autoloadPackage) {
-            if ($autoloadPackage === $this->composer->getPackage()) {
+            if ($autoloadPackage === $rootPackage) {
                 $downloadPath = '';
             } else {
                 $downloadPath = $this->getInstallPath($autoloadPackage, $globalRepo && $globalRepo->hasPackage($autoloadPackage));
@@ -195,7 +196,7 @@ class PluginManager
             $autoloads[] = array($autoloadPackage, $downloadPath);
         }
 
-        $map = $generator->parseAutoloads($autoloads, $this->composer->getPackage());
+        $map = $generator->parseAutoloads($autoloads, $rootPackage);
         $classLoader = $generator->createLoader($map);
         $classLoader->register();
 

tests/Composer/Test/Plugin/PluginInstallerTest.php

@@ -18,6 +18,7 @@ use Composer\Installer\PluginInstaller;
 use Composer\Package\CompletePackage;
 use Composer\Package\Loader\JsonLoader;
 use Composer\Package\Loader\ArrayLoader;
+use Composer\Package\RootPackage;
 use Composer\Plugin\PluginManager;
 use Composer\IO\BufferIO;
 use Composer\EventDispatcher\EventDispatcher;
@@ -111,6 +112,7 @@ class PluginInstallerTest extends TestCase
         $this->composer->setInstallationManager($im);
         $this->composer->setAutoloadGenerator($this->autoloadGenerator);
         $this->composer->setEventDispatcher(new EventDispatcher($this->composer, $this->io));
+        $this->composer->setPackage(new RootPackage('dummy/root', '1.0.0.0', '1.0.0'));
 
         $this->pm = new PluginManager($this->io, $this->composer);
         $this->composer->setPluginManager($this->pm);