[Debug] ensured that a fatal PHP error is actually fatal after being handled by our error handler

src/Symfony/Component/Debug/ErrorHandler.php

@@ -13,6 +13,7 @@ namespace Symfony\Component\Debug;
 
 use Symfony\Component\Debug\Exception\FatalErrorException;
 use Symfony\Component\Debug\Exception\ContextErrorException;
+use Symfony\Component\Debug\Exception\DummyException;
 use Psr\Log\LoggerInterface;
 
 /**
@@ -129,13 +130,29 @@ class ErrorHandler
 
             // Exceptions thrown from error handlers are sometimes not caught by the exception
             // handler, so we invoke it directly (https://bugs.php.net/bug.php?id=54275)
-            $exceptionHandler = set_exception_handler(function() {});
+            $exceptionHandler = set_exception_handler(function () {});
             restore_exception_handler();
 
             if (is_array($exceptionHandler) && $exceptionHandler[0] instanceof ExceptionHandler) {
                 $exceptionHandler[0]->handle($exception);
 
-                return true;
+                if (!class_exists('Symfony\Component\Debug\Exception\DummyException')) {
+                    require __DIR__.'/Exception/DummyException.php';
+                }
+
+                // we must stop the PHP script execution, as the exception has
+                // already been dealt with, so, let's throw an exception that
+                // will be catched by a dummy exception handler
+                set_exception_handler(function (\Exception $e) use ($exceptionHandler) {
+                    if (!$e instanceof DummyException) {
+                        // happens if our dummy exception is catched by a
+                        // catch-all from user code, in which case, let's the
+                        // current handler handle this "new" exception
+                        call_user_func($exceptionHandler, $e);
+                    }
+                });
+
+                throw new DummyException();
             }
         }
 

src/Symfony/Component/Debug/Exception/DummyException.php

@@ -0,0 +1,21 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Debug\Exception;
+
+/**
+ * Used to stop execution of a PHP script after handling a fatal error.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class DummyException extends \ErrorException
+{
+}

src/Symfony/Component/Debug/Tests/ErrorHandlerTest.php

@@ -12,6 +12,7 @@
 namespace Symfony\Component\Debug\Tests;
 
 use Symfony\Component\Debug\ErrorHandler;
+use Symfony\Component\Debug\Exception\DummyException;
 
 /**
  * ErrorHandlerTest
@@ -81,11 +82,15 @@ class ErrorHandlerTest extends \PHPUnit_Framework_TestCase
         $bar = 123;
 
         // trigger compile time error
-        eval(<<<'PHP'
+        try {
+            eval(<<<'PHP'
 class _BaseCompileTimeError { function foo() {} }
 class _CompileTimeError extends _BaseCompileTimeError { function foo($invalid) {} }
 PHP
-        );
+            );
+        } catch (DummyException $e) {
+            // if an exception is thrown, the test passed
+        }
 
         restore_error_handler();
         restore_exception_handler();
@@ -100,7 +105,7 @@ PHP
         $exceptionCheck = function($exception) use ($that) {
             $that->assertInstanceOf('Symfony\Component\Debug\Exception\ContextErrorException', $exception);
             $that->assertEquals(E_NOTICE, $exception->getSeverity());
-            $that->assertEquals(__LINE__ + 36, $exception->getLine());
+            $that->assertEquals(__LINE__ + 40, $exception->getLine());
             $that->assertEquals(__FILE__, $exception->getFile());
             $that->assertRegexp('/^Notice: Undefined variable: (foo|bar)/', $exception->getMessage());
             $that->assertArrayHasKey('foobar', $exception->getContext());
@@ -121,12 +126,16 @@ PHP
             $that->assertEquals('->', $trace[2]['type']);
         };
 
-        $exceptionHandler->expects($this->exactly(3))
+        $exceptionHandler->expects($this->once())
             ->method('handle')
             ->will($this->returnCallback($exceptionCheck));
         ErrorHandler::register();
 
-        self::triggerNotice($this);
+        try {
+            self::triggerNotice($this);
+        } catch (DummyException $e) {
+            // if an exception is thrown, the test passed
+        }
 
         restore_error_handler();
     }