Merge branch '4.0'

* 4.0:
  [Form] Fixed ContextErrorException in FileType
  [DI] Fix handling of inlined definitions by ContainerBuilder
  [Security] remove unused variable
  [DI] Fix infinite loop when analyzing references
  [Lock][Process][FrameworkBundle] fix tests
  Display a nice error message if the form/serializer component is missing.
  [SecurityBundle] providerIds is undefined error when firewall provider is not specified
  [SecurityBundle] providerIds is undefined error when firewall provider is not specified
  [SecurityBundle] providerIds is undefined error when firewall provider is not specified
  Force phpunit-bridge update (bis)
  [Bridge/PhpUnit] Fix disabling global state preservation
  Incorrect dot on method loadChoices in upgrade doc

Author: nicolas-grekas

DependencyInjection/FrameworkExtension.php

@@ -137,10 +137,6 @@ public function load(array $configs, ContainerBuilder $container)
                 throw new LogicException('Translation support cannot be enabled as the Translation component is not installed.');
             }
 
-            if (!class_exists('Symfony\Component\Translation\Translator') && $this->isConfigEnabled($container, $config['validation'])) {
-                throw new LogicException('Validation support cannot be enabled as the Translation component is not installed.');
-            }
-
             if (class_exists(Translator::class)) {
                 $loader->load('identity_translator.xml');
             }
@@ -184,6 +180,10 @@ public function load(array $configs, ContainerBuilder $container)
         }
 
         if ($this->isConfigEnabled($container, $config['form'])) {
+            if (!class_exists('Symfony\Component\Form\Form')) {
+                throw new LogicException('Form support cannot be enabled as the Form component is not installed.');
+            }
+
             $this->formConfigEnabled = true;
             $this->registerFormConfiguration($config, $container, $loader);
 
@@ -231,6 +231,10 @@ public function load(array $configs, ContainerBuilder $container)
         $this->registerPropertyAccessConfiguration($config['property_access'], $container, $loader);
 
         if ($this->isConfigEnabled($container, $config['serializer'])) {
+            if (!class_exists('Symfony\Component\Serializer\Serializer')) {
+                throw new LogicException('Serializer support cannot be enabled as the Serializer component is not installed.');
+            }
+
             $this->registerSerializerConfiguration($config['serializer'], $container, $loader);
         }
 
@@ -923,6 +927,7 @@ private function registerTranslatorConfiguration(array $config, ContainerBuilder
                     return 2 === substr_count($file->getBasename(), '.') && preg_match('/\.\w+$/', $file->getBasename());
                 })
                 ->in($dirs)
+                ->sortByName()
             ;
 
             foreach ($finder as $file) {
@@ -1032,7 +1037,7 @@ private function registerValidatorMapping(ContainerBuilder $container, array $co
 
     private function registerMappingFilesFromDir($dir, callable $fileRecorder)
     {
-        foreach (Finder::create()->followLinks()->files()->in($dir)->name('/\.(xml|ya?ml)$/') as $file) {
+        foreach (Finder::create()->followLinks()->files()->in($dir)->name('/\.(xml|ya?ml)$/')->sortByName() as $file) {
             $fileRecorder($file->getExtension(), $file->getRealPath());
         }
     }