bug #40065 [ErrorHandler] fix handling messages with null bytes from …

…anonymous classes (nicolas-grekas)

This PR was merged into the 4.4 branch.

Discussion
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[ErrorHandler] fix handling messages with null bytes from anonymous classes

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

PHP truncates error messages at null bytes before calling userland error handlers (known behavior in PHP, marked as "won't fix".)

This doesn't play well with anonymous classes.

This PR works around the issue by getting the message from the stack trace.

Commits
-------

ac94746 [ErrorHandler] fix handling messages with null bytes from anonymous classes

src/Symfony/Component/ErrorHandler/ErrorHandler.php

@@ -422,11 +422,7 @@ public function handleError(int $type, string $message, string $file, int $line)
             return false;
         }
 
-        if (false !== strpos($message, "@anonymous\0")) {
-            $logMessage = $this->parseAnonymousClass($message);
-        } else {
-            $logMessage = $this->levels[$type].': '.$message;
-        }
+        $logMessage = $this->levels[$type].': '.$message;
 
         if (null !== self::$toStringException) {
             $errorAsException = self::$toStringException;
@@ -455,6 +451,23 @@ public function handleError(int $type, string $message, string $file, int $line)
                 return true;
             }
         } else {
+            if (false !== strpos($message, '@anonymous')) {
+                $backtrace = debug_backtrace(false, 5);
+
+                for ($i = 1; isset($backtrace[$i]); ++$i) {
+                    if (isset($backtrace[$i]['function'], $backtrace[$i]['args'][0])
+                        && ('trigger_error' === $backtrace[$i]['function'] || 'user_error' === $backtrace[$i]['function'])
+                    ) {
+                        if ($backtrace[$i]['args'][0] !== $message) {
+                            $message = $this->parseAnonymousClass($backtrace[$i]['args'][0]);
+                            $logMessage = $this->levels[$type].': '.$message;
+                        }
+
+                        break;
+                    }
+                }
+            }
+
             $errorAsException = new \ErrorException($logMessage, 0, $type, $file, $line);
 
             if ($throw || $this->tracedErrors & $type) {

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

@@ -368,22 +368,20 @@ public function testHandleUserError()
 
     public function testHandleErrorWithAnonymousClass()
     {
+        $anonymousObject = new class() extends \stdClass {
+        };
+
         $handler = ErrorHandler::register();
-        $handler->throwAt(3, true);
         try {
-            $handler->handleError(3, 'foo '.\get_class(new class() extends \stdClass {
-            }).' bar', 'foo.php', 12);
+            trigger_error('foo '.\get_class($anonymousObject).' bar', \E_USER_WARNING);
             $this->fail('Exception expected.');
         } catch (\ErrorException $e) {
         } finally {
             restore_error_handler();
             restore_exception_handler();
         }
 
-        $this->assertSame('foo stdClass@anonymous bar', $e->getMessage());
-        $this->assertSame(3, $e->getSeverity());
-        $this->assertSame('foo.php', $e->getFile());
-        $this->assertSame(12, $e->getLine());
+        $this->assertSame('User Warning: foo stdClass@anonymous bar', $e->getMessage());
     }
 
     public function testHandleDeprecation()