Merge branch '4.1' into 4.2

* 4.1:
  [Routing] fix trailing slash redirections involving a trailing var
  [EventDispatcher] Revers event tracing order
  [Security] Prefer clone over unserialize(serialize()) for user refreshment
  [Console] OutputFormatter: move strtolower to createStyleFromString
  Adjust tests to work in the armhf architecture. Fixes #29281.
  Vietnamese translations improvement
  [Form] Fixed FormErrorIterator class phpdoc
  Renamed test controller from Controller to TestController so it doesn't show up in the IDE autocomplete.
  Don't use he in docs when its not needed
  EventSubscriberInterface isn't a man
  fixed public directory of web server and assets install when configured in composer.json

Author: nicolas-grekas

Command/AssetsInstallCommand.php

@@ -18,6 +18,7 @@
 use Symfony\Component\Console\Input\InputOption;
 use Symfony\Component\Console\Output\OutputInterface;
 use Symfony\Component\Console\Style\SymfonyStyle;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\Filesystem\Exception\IOException;
 use Symfony\Component\Filesystem\Filesystem;
 use Symfony\Component\Finder\Finder;
@@ -56,7 +57,7 @@ protected function configure()
     {
         $this
             ->setDefinition(array(
-                new InputArgument('target', InputArgument::OPTIONAL, 'The target directory', 'public'),
+                new InputArgument('target', InputArgument::OPTIONAL, 'The target directory', null),
             ))
             ->addOption('symlink', null, InputOption::VALUE_NONE, 'Symlinks the assets instead of copying it')
             ->addOption('relative', null, InputOption::VALUE_NONE, 'Make relative symlinks')
@@ -94,6 +95,10 @@ protected function execute(InputInterface $input, OutputInterface $output)
         $kernel = $this->getApplication()->getKernel();
         $targetArg = rtrim($input->getArgument('target'), '/');
 
+        if (!$targetArg) {
+            $targetArg = $this->getPublicDirectory($this->getContainer());
+        }
+
         if (!is_dir($targetArg)) {
             $targetArg = $kernel->getProjectDir().'/'.$targetArg;
 
@@ -250,4 +255,27 @@ private function hardCopy(string $originDir, string $targetDir): string
 
         return self::METHOD_COPY;
     }
+
+    private function getPublicDirectory(ContainerInterface $container)
+    {
+        $defaultPublicDir = 'public';
+
+        if (!$container->hasParameter('kernel.project_dir')) {
+            return $defaultPublicDir;
+        }
+
+        $composerFilePath = $container->getParameter('kernel.project_dir').'/composer.json';
+
+        if (!file_exists($composerFilePath)) {
+            return $defaultPublicDir;
+        }
+
+        $composerConfig = json_decode(file_get_contents($composerFilePath), true);
+
+        if (isset($composerConfig['extra']['public-dir'])) {
+            return $composerConfig['extra']['public-dir'];
+        }
+
+        return $defaultPublicDir;
+    }
 }