From f405b4d5a0e2a169a5bef8f7bac4f97b50ad431d Mon Sep 17 00:00:00 2001
From: Nicolas Grekas <nicolas.grekas@gmail.com>
Date: Sun, 23 Sep 2018 10:13:20 +0200
Subject: [PATCH] [HttpFoundation] fix hidding warnings from session handlers

---
 .../Session/Storage/NativeSessionStorage.php  | 25 +++++++------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php b/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php
index a9a54b49dd..1ec5c7ff4e 100644
--- a/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php
+++ b/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php
@@ -230,29 +230,22 @@ class NativeSessionStorage implements SessionStorageInterface
             unset($_SESSION[$key]);
         }
 
-        // Register custom error handler to catch a possible failure warning during session write
-        set_error_handler(function ($errno, $errstr, $errfile, $errline) {
-            throw new \ErrorException($errstr, $errno, E_WARNING, $errfile, $errline);
-        }, E_WARNING);
+        // Register error handler to add information about the current save handler
+        $previousHandler = set_error_handler(function ($type, $msg, $file, $line) use (&$previousHandler) {
+            if (E_WARNING === $type && 0 === strpos($msg, 'session_write_close():')) {
+                $handler = $this->saveHandler instanceof SessionHandlerProxy ? $this->saveHandler->getHandler() : $this->saveHandler;
+                $msg = sprintf('session_write_close(): Failed to write session data with "%s" handler', \get_class($handler));
+            }
+
+            return $previousHandler ? $previousHandler($type, $msg, $file, $line) : false;
+        });
 
         try {
-            $e = null;
             session_write_close();
-        } catch (\ErrorException $e) {
         } finally {
             restore_error_handler();
             $_SESSION = $session;
         }
-        if (null !== $e) {
-            // The default PHP error message is not very helpful, as it does not give any information on the current save handler.
-            // Therefore, we catch this error and trigger a warning with a better error message
-            $handler = $this->getSaveHandler();
-            if ($handler instanceof SessionHandlerProxy) {
-                $handler = $handler->getHandler();
-            }
-
-            trigger_error(sprintf('session_write_close(): Failed to write session data with %s handler', \get_class($handler)), E_USER_WARNING);
-        }
 
         $this->closed = true;
         $this->started = false;