Reverted inadvertent API change, improved API documentation

src/Composer/Repository/WritableArrayRepository.php

@@ -42,12 +42,11 @@ class WritableArrayRepository extends ArrayRepository implements WritableReposit
     {
         $packages = $this->getPackages();
 
-        // get at most one package of each (name, version) combination, prefering non-aliased ones
+        // get at most one package of each name, preferring non-aliased ones
         $packagesByName = array();
         foreach ($packages as $package) {
-            $index = $package->getName() . $package->getVersion();
+            if (!isset($packagesByName[$package->getName()]) || $packagesByName[$package->getName()] instanceof AliasPackage) {
-            if (!isset($packagesByName[$index]) || $packagesByName[$index] instanceof AliasPackage) {
+                $packagesByName[$package->getName()] = $package;
-                $packagesByName[$index] = $package;
             }
         }
 

src/Composer/Repository/WritableRepositoryInterface.php

@@ -41,14 +41,14 @@ interface WritableRepositoryInterface extends RepositoryInterface
     public function removePackage(PackageInterface $package);
 
     /**
-     * Get unique packages, with aliases resolved and removed
+     * Get unique packages (at most one package of each name), with aliases resolved and removed.
      *
      * @return PackageInterface[]
      */
     public function getCanonicalPackages();
 
     /**
-     * Forces a reload of all packages
+     * Forces a reload of all packages.
      */
     public function reload();
 }

tests/Composer/Test/Repository/WritableArrayRepositoryTest.php

@@ -1,29 +0,0 @@
-<?php
-
-/*
- * This file is part of Composer.
- *
- * (c) Nils Adermann <naderman@naderman.de>
- *     Jordi Boggiano <j.boggiano@seld.be>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Composer\Test\Repository;
-
-use Composer\Repository\WritableArrayRepository;
-use Composer\TestCase;
-
-final class WritableArrayRepositoryTest extends TestCase
-{
-    public function testGetCanonicalPackagesReturnsDifferentVersionsOfSameNamedPackage()
-    {
-        $repository = new WritableArrayRepository();
-
-        $repository->addPackage($this->getPackage('foo', 1));
-        $repository->addPackage($this->getPackage('foo', 2));
-
-        $this->assertCount(2, $repository->getCanonicalPackages());
-    }
-}