Merge branch '5.4' into 6.4

* 5.4:
  Tweak error/exception handler registration

Author: nicolas-grekas

EventListener/DebugHandlersListener.php

@@ -47,7 +47,8 @@ public function __construct(?callable $exceptionHandler = null, bool|LoggerInter
             // BC with Symfony 5
             $webMode = null;
         }
-        $handler = set_exception_handler('is_int');
+
+        $handler = set_exception_handler('var_dump');
         $this->earlyHandler = \is_array($handler) ? $handler[0] : null;
         restore_exception_handler();
 
@@ -94,7 +95,7 @@ public function configure(?object $event = null): void
             }
         }
         if ($this->exceptionHandler) {
-            $handler = set_exception_handler(static fn () => null);
+            $handler = set_exception_handler('var_dump');
             $handler = \is_array($handler) ? $handler[0] : null;
             restore_exception_handler();
 

EventListener/ErrorListener.php

@@ -104,11 +104,11 @@ public function onKernelException(ExceptionEvent $event)
 
         $throwable = $event->getThrowable();
 
-        if ($exceptionHandler = set_exception_handler(var_dump(...))) {
-            restore_exception_handler();
-            if (\is_array($exceptionHandler) && $exceptionHandler[0] instanceof ErrorHandler) {
-                $throwable = $exceptionHandler[0]->enhanceError($event->getThrowable());
-            }
+        $exceptionHandler = set_exception_handler('var_dump');
+        restore_exception_handler();
+
+        if (\is_array($exceptionHandler) && $exceptionHandler[0] instanceof ErrorHandler) {
+            $throwable = $exceptionHandler[0]->enhanceError($event->getThrowable());
         }
 
         $request = $this->duplicateRequest($throwable, $event->getRequest());