Merge branch '3.1'

* 3.1:
  fixed bad merge
  Fix PHP 7.1 related failures
  [VarDumper] Fix for 7.1
  fixed CS
  Added class existence check if is_subclass_of() fails in compiler passes
  Fix the DBAL session handler version check for Postgresql

Author: fabpot

CacheWarmer/CacheWarmer.php

@@ -20,7 +20,7 @@ abstract class CacheWarmer implements CacheWarmerInterface
 {
     protected function writeCacheFile($file, $content)
     {
-        $tmpFile = tempnam(dirname($file), basename($file));
+        $tmpFile = @tempnam(dirname($file), basename($file));
         if (false !== @file_put_contents($tmpFile, $content) && @rename($tmpFile, $file)) {
             @chmod($file, 0666 & ~umask());
 

DependencyInjection/FragmentRendererPass.php

@@ -53,7 +53,12 @@ public function process(ContainerBuilder $container)
 
             $class = $container->getParameterBag()->resolveValue($def->getClass());
             $interface = 'Symfony\Component\HttpKernel\Fragment\FragmentRendererInterface';
+
             if (!is_subclass_of($class, $interface)) {
+                if (!class_exists($class, false)) {
+                    throw new \InvalidArgumentException(sprintf('Class "%s" used for service "%s" cannot be found.', $class, $id));
+                }
+
                 throw new \InvalidArgumentException(sprintf('Service "%s" must implement interface "%s".', $id, $interface));
             }