Fix UniversalClassLoader matching collisions.

The current `loadClass()` implementation tries to load a class from the first matching prefix then stops, producing false-negative results. This is especially evident in groups of related libraries, such as Doctrine:

    Doctrine
    Doctrine\Common
    Doctrine\Common\DataFixtures
    Doctrine\DBAL
    Doctrine\DBAL\Migrations

Each of these libraries is submoduled into a different vendor directory. Depending on what order these libraries are added to a UniversalClassLoader instance, classes may or may not actually be loaded. This fix continues searching registered namespaces and prefixes if the first partial match is negative.

src/Symfony/Component/HttpFoundation/UniversalClassLoader.php

@@ -132,13 +132,12 @@ class UniversalClassLoader
             $namespace = substr($class, 0, $pos);
             foreach ($this->namespaces as $ns => $dir) {
                 if (0 === strpos($namespace, $ns)) {
-                    $class = substr($class, $pos + 1);
-                    $file = $dir.DIRECTORY_SEPARATOR.str_replace('\\', DIRECTORY_SEPARATOR, $namespace).DIRECTORY_SEPARATOR.str_replace('_', DIRECTORY_SEPARATOR, $class).'.php';
+                    $className = substr($class, $pos + 1);
+                    $file = $dir.DIRECTORY_SEPARATOR.str_replace('\\', DIRECTORY_SEPARATOR, $namespace).DIRECTORY_SEPARATOR.str_replace('_', DIRECTORY_SEPARATOR, $className).'.php';
                     if (file_exists($file)) {
                         require $file;
+                        return;
                     }
-
-                    return;
                 }
             }
         } else {
@@ -148,9 +147,8 @@ class UniversalClassLoader
                     $file = $dir.DIRECTORY_SEPARATOR.str_replace('_', DIRECTORY_SEPARATOR, $class).'.php';
                     if (file_exists($file)) {
                         require $file;
+                        return;
                     }
-
-                    return;
                 }
             }
         }

tests/Symfony/Tests/Component/HttpFoundation/Fixtures/alpha/NamespaceCollision/A/Bar.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace NamespaceCollision\A;
+
+class Bar
+{
+    public static $loaded = true;
+}

tests/Symfony/Tests/Component/HttpFoundation/Fixtures/alpha/NamespaceCollision/A/Foo.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace NamespaceCollision\A;
+
+class Foo
+{
+    public static $loaded = true;
+}

tests/Symfony/Tests/Component/HttpFoundation/Fixtures/alpha/PrefixCollision/A/Bar.php

@@ -0,0 +1,6 @@
+<?php
+
+class PrefixCollision_A_Bar
+{
+    public static $loaded = true;
+}

tests/Symfony/Tests/Component/HttpFoundation/Fixtures/alpha/PrefixCollision/A/Foo.php

@@ -0,0 +1,6 @@
+<?php
+
+class PrefixCollision_A_Foo
+{
+    public static $loaded = true;
+}

tests/Symfony/Tests/Component/HttpFoundation/Fixtures/beta/NamespaceCollision/A/B/Bar.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace NamespaceCollision\A\B;
+
+class Bar
+{
+    public static $loaded = true;
+}

tests/Symfony/Tests/Component/HttpFoundation/Fixtures/beta/NamespaceCollision/A/B/Foo.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace NamespaceCollision\A\B;
+
+class Foo
+{
+    public static $loaded = true;
+}

tests/Symfony/Tests/Component/HttpFoundation/Fixtures/beta/PrefixCollision/A/B/Bar.php

@@ -0,0 +1,6 @@
+<?php
+
+class PrefixCollision_A_B_Bar
+{
+    public static $loaded = true;
+}

tests/Symfony/Tests/Component/HttpFoundation/Fixtures/beta/PrefixCollision/A/B/Foo.php

@@ -0,0 +1,6 @@
+<?php
+
+class PrefixCollision_A_B_Foo
+{
+    public static $loaded = true;
+}

tests/Symfony/Tests/Component/HttpFoundation/UniversalClassLoaderTest.php

@@ -37,5 +37,104 @@ class UniversalClassLoaderTest extends \PHPUnit_Framework_TestCase
             array('\\Pearlike_Bar',    '\\Pearlike_Bar',    '->loadClass() loads Pearlike_Bar class with a leading slash'),
         );
     }
-}
 
+    /**
+     * @dataProvider namespaceCollisionClassProvider
+     */
+    public function testLoadClassNamespaceCollision($namespaces, $className, $message)
+    {
+        $loader = new UniversalClassLoader();
+        $loader->registerNamespaces($namespaces);
+
+        $loader->loadClass($className);
+        $this->assertTrue(class_exists($className), $message);
+    }
+
+    public static function namespaceCollisionClassProvider()
+    {
+        return array(
+            array(
+                array(
+                    'NamespaceCollision\\A' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/alpha',
+                    'NamespaceCollision\\A\\B' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/beta',
+                ),
+                'NamespaceCollision\A\Foo',
+                '->loadClass() loads NamespaceCollision\A\Foo from alpha.',
+            ),
+            array(
+                array(
+                    'NamespaceCollision\\A\\B' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/beta',
+                    'NamespaceCollision\\A' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/alpha',
+                ),
+                'NamespaceCollision\A\Bar',
+                '->loadClass() loads NamespaceCollision\A\Bar from alpha.',
+            ),
+            array(
+                array(
+                    'NamespaceCollision\\A' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/alpha',
+                    'NamespaceCollision\\A\\B' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/beta',
+                ),
+                'NamespaceCollision\A\B\Foo',
+                '->loadClass() loads NamespaceCollision\A\B\Foo from beta.',
+            ),
+            array(
+                array(
+                    'NamespaceCollision\\A\\B' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/beta',
+                    'NamespaceCollision\\A' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/alpha',
+                ),
+                'NamespaceCollision\A\B\Bar',
+                '->loadClass() loads NamespaceCollision\A\B\Bar from beta.',
+            ),
+        );
+    }
+
+    /**
+     * @dataProvider prefixCollisionClassProvider
+     */
+    public function testLoadClassPrefixCollision($prefixes, $className, $message)
+    {
+        $loader = new UniversalClassLoader();
+        $loader->registerPrefixes($prefixes);
+
+        $loader->loadClass($className);
+        $this->assertTrue(class_exists($className), $message);
+    }
+
+    public static function prefixCollisionClassProvider()
+    {
+        return array(
+            array(
+                array(
+                    'PrefixCollision_A_' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/alpha',
+                    'PrefixCollision_A_B_' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/beta',
+                ),
+                'PrefixCollision_A_Foo',
+                '->loadClass() loads PrefixCollision_A_Foo from alpha.',
+            ),
+            array(
+                array(
+                    'PrefixCollision_A_B_' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/beta',
+                    'PrefixCollision_A_' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/alpha',
+                ),
+                'PrefixCollision_A_Bar',
+                '->loadClass() loads PrefixCollision_A_Bar from alpha.',
+            ),
+            array(
+                array(
+                    'PrefixCollision_A_' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/alpha',
+                    'PrefixCollision_A_B_' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/beta',
+                ),
+                'PrefixCollision_A_B_Foo',
+                '->loadClass() loads PrefixCollision_A_B_Foo from beta.',
+            ),
+            array(
+                array(
+                    'PrefixCollision_A_B_' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/beta',
+                    'PrefixCollision_A_' => __DIR__ . DIRECTORY_SEPARATOR . 'Fixtures/alpha',
+                ),
+                'PrefixCollision_A_B_Bar',
+                '->loadClass() loads PrefixCollision_A_B_Bar from beta.',
+            ),
+        );
+    }
+}