[Debug] Fixed ClassNotFoundFatalErrorHandler which could cause a fata…

…l error.

It might happen that require_once will include a file second time (for
example with links or case-changed paths). Therefore we need to check
if a class exists before requiring the file.

src/Symfony/Component/Debug/FatalErrorHandler/ClassNotFoundFatalErrorHandler.php

@@ -110,7 +110,7 @@ private function getClassCandidates($class)
             if ($function[0] instanceof ComposerClassLoader || $function[0] instanceof SymfonyClassLoader) {
                 foreach ($function[0]->getPrefixes() as $paths) {
                     foreach ($paths as $path) {
-                        $classes = array_merge($classes, $this->findClassInPath($function[0], $path, $class));
+                        $classes = array_merge($classes, $this->findClassInPath($path, $class));
                     }
                 }
             }
@@ -119,7 +119,13 @@ private function getClassCandidates($class)
         return $classes;
     }
 
-    private function findClassInPath($loader, $path, $class)
+    /**
+     * @param string $path
+     * @param string $class
+     *
+     * @return array
+     */
+    private function findClassInPath($path, $class)
     {
         if (!$path = realpath($path)) {
             return array();
@@ -128,33 +134,48 @@ private function findClassInPath($loader, $path, $class)
         $classes = array();
         $filename = $class.'.php';
         foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($path), \RecursiveIteratorIterator::LEAVES_ONLY) as $file) {
-            if ($filename == $file->getFileName() && $class = $this->convertFileToClass($loader, $path, $file->getPathName())) {
+            if ($filename == $file->getFileName() && $class = $this->convertFileToClass($path, $file->getPathName())) {
                 $classes[] = $class;
             }
         }
 
         return $classes;
     }
 
-    private function convertFileToClass($loader, $path, $file)
+    /**
+     * @param string $path
+     * @param string $file
+     *
+     * @return string|null
+     */
+    private function convertFileToClass($path, $file)
     {
+        $namespacedClass = str_replace(array($path.'/', '.php', '/'), array('', '', '\\'), $file);
+        $pearClass = str_replace('\\', '_', $namespacedClass);
+
         // We cannot use the autoloader here as most of them use require; but if the class
         // is not found, the new autoloader call will require the file again leading to a
         // "cannot redeclare class" error.
-        require_once $file;
-
-        $file = str_replace(array($path.'/', '.php'), array('', ''), $file);
+        if (!$this->classExists($namespacedClass) && !$this->classExists($pearClass)) {
+            require_once $file;
+        }
 
-        // is it a namespaced class?
-        $class = str_replace('/', '\\', $file);
-        if (class_exists($class, false) || interface_exists($class, false) || (function_exists('trait_exists') && trait_exists($class, false))) {
-            return $class;
+        if ($this->classExists($namespacedClass)) {
+            return $namespacedClass;
         }
 
-        // is it a PEAR-like class name instead?
-        $class = str_replace('/', '_', $file);
-        if (class_exists($class, false) || interface_exists($class, false) || (function_exists('trait_exists') && trait_exists($class, false))) {
-            return $class;
+        if ($this->classExists($pearClass)) {
+            return $pearClass;
         }
     }
+
+    /**
+     * @param string $class
+     *
+     * @return Boolean
+     */
+    private function classExists($class)
+    {
+        return class_exists($class, false) || interface_exists($class, false) || (function_exists('trait_exists') && trait_exists($class, false));
+    }
 }

src/Symfony/Component/Debug/Tests/FatalErrorHandler/ClassNotFoundFatalErrorHandlerTest.php

@@ -81,4 +81,25 @@ public function provideClassNotFoundData()
             ),
         );
     }
+
+    public function testCannotRedeclareClass()
+    {
+        if (!file_exists(__DIR__.'/../FIXTURES/REQUIREDTWICE.PHP')) {
+            $this->markTestSkipped('Can only be run on case insensitive filesystems');
+        }
+
+        require_once __DIR__.'/../FIXTURES/REQUIREDTWICE.PHP';
+
+        $error = array(
+            'type' => 1,
+            'line' => 12,
+            'file' => 'foo.php',
+            'message' => 'Class \'Foo\\Bar\\RequiredTwice\' not found',
+        );
+
+        $handler = new ClassNotFoundFatalErrorHandler();
+        $exception = $handler->handleError($error, new FatalErrorException('', 0, $error['type'], $error['file'], $error['line']));
+
+        $this->assertInstanceof('Symfony\Component\Debug\Exception\ClassNotFoundException', $exception);
+    }
 }

src/Symfony/Component/Debug/Tests/Fixtures/RequiredTwice.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+class RequiredTwice
+{
+}