Merge branch '3.4' into 4.3

* 3.4:
  Return null as Expire header if it was set to null
  [ProxyManager] remove ProxiedMethodReturnExpression polyfill
  fix dumping not inlined scalar tag values

composer.json

@@ -136,8 +136,7 @@
             "Symfony\\Component\\": "src/Symfony/Component/"
         },
         "classmap": [
-            "src/Symfony/Component/Intl/Resources/stubs",
-            "src/Symfony/Bridge/ProxyManager/Legacy/ProxiedMethodReturnExpression.php"
+            "src/Symfony/Component/Intl/Resources/stubs"
         ],
         "exclude-from-classmap": [
             "**/Tests/"

src/Symfony/Bridge/ProxyManager/Legacy/ProxiedMethodReturnExpression.php

@@ -1,75 +0,0 @@
-<?php
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace ProxyManager\Generator\Util;
-
-use Composer\Autoload\ClassLoader;
-use ProxyManager\Version;
-
-if (class_exists(Version::class) && version_compare(\defined(Version::class.'::VERSION') ? Version::VERSION : Version::getVersion(), '2.5', '<')) {
-    /**
-     * Utility class to generate return expressions in method, given a method signature.
-     *
-     * This is required since return expressions may be forbidden by the method signature (void).
-     *
-     * @author Marco Pivetta <ocramius@gmail.com>
-     * @license MIT
-     *
-     * @see https://github.com/Ocramius/ProxyManager
-     */
-    final class ProxiedMethodReturnExpression
-    {
-        public static function generate(string $returnedValueExpression, ?\ReflectionMethod $originalMethod): string
-        {
-            $originalReturnType = null === $originalMethod ? null : $originalMethod->getReturnType();
-
-            $originalReturnTypeName = null === $originalReturnType ? null : $originalReturnType->getName();
-
-            if ('void' === $originalReturnTypeName) {
-                return $returnedValueExpression.";\nreturn;";
-            }
-
-            return 'return '.$returnedValueExpression.';';
-        }
-    }
-} else {
-    // Fallback to the original class by unregistering this file from composer class loader
-    $getComposerClassLoader = static function ($functionLoader) use (&$getComposerClassLoader) {
-        if (\is_array($functionLoader)) {
-            $functionLoader = $functionLoader[0];
-        }
-        if (!\is_object($functionLoader)) {
-            return null;
-        }
-        if ($functionLoader instanceof ClassLoader) {
-            return $functionLoader;
-        }
-        if ($functionLoader instanceof \Symfony\Component\Debug\DebugClassLoader) {
-            return $getComposerClassLoader($functionLoader->getClassLoader());
-        }
-        if ($functionLoader instanceof \Symfony\Component\ErrorHandler\DebugClassLoader) {
-            return $getComposerClassLoader($functionLoader->getClassLoader());
-        }
-
-        return null;
-    };
-
-    $classLoader = null;
-    $functions = spl_autoload_functions();
-    while (null === $classLoader && $functions) {
-        $classLoader = $getComposerClassLoader(array_shift($functions));
-    }
-    $getComposerClassLoader = null;
-
-    if (null !== $classLoader) {
-        $classLoader->addClassMap([ProxiedMethodReturnExpression::class => null]);
-        $classLoader->loadClass(ProxiedMethodReturnExpression::class);
-    }
-}

src/Symfony/Bridge/ProxyManager/composer.json

@@ -28,7 +28,6 @@
     },
     "autoload": {
         "psr-4": { "Symfony\\Bridge\\ProxyManager\\": "" },
-        "classmap": [ "Legacy/ProxiedMethodReturnExpression.php" ],
         "exclude-from-classmap": [
             "/Tests/"
         ]

src/Symfony/Component/HttpFoundation/HeaderBag.php

@@ -121,7 +121,15 @@ class HeaderBag implements \IteratorAggregate, \Countable
         }
 
         if ($first) {
-            return \count($headers[$key]) ? (string) $headers[$key][0] : $default;
+            if (!$headers[$key]) {
+                return $default;
+            }
+
+            if (null === $headers[$key][0]) {
+                return null;
+            }
+
+            return (string) $headers[$key][0];
         }
 
         return $headers[$key];

src/Symfony/Component/HttpFoundation/Tests/HeaderBagTest.php

@@ -48,6 +48,13 @@ class HeaderBagTest extends TestCase
         $this->assertInstanceOf('DateTime', $headerDate);
     }
 
+    public function testGetDateNull()
+    {
+        $bag = new HeaderBag(['foo' => null]);
+        $headerDate = $bag->getDate('foo');
+        $this->assertNull($headerDate);
+    }
+
     public function testGetDateException()
     {
         $this->expectException('RuntimeException');
@@ -96,6 +103,9 @@ class HeaderBagTest extends TestCase
         $bag->set('foo', 'bor', false);
         $this->assertEquals('bar', $bag->get('foo'), '->get return first value');
         $this->assertEquals(['bar', 'bor'], $bag->get('foo', 'nope', false), '->get return all values as array');
+
+        $bag->set('baz', null);
+        $this->assertNull($bag->get('baz', 'nope'), '->get return null although different default value is given');
     }
 
     public function testSetAssociativeArray()

src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php

@@ -370,6 +370,12 @@ class ResponseTest extends ResponseTestCase
         $this->assertNull($response->headers->get('Expires'), '->expire() removes the Expires header when the response is fresh');
     }
 
+    public function testNullExpireHeader()
+    {
+        $response = new Response(null, 200, ['Expires' => null]);
+        $this->assertNull($response->getExpires());
+    }
+
     public function testGetTtl()
     {
         $response = new Response();

src/Symfony/Component/Yaml/Dumper.php

@@ -85,6 +85,10 @@ class Dumper
                     } else {
                         $output .= "\n";
                         $output .= $this->dump($value->getValue(), $inline - 1, $dumpAsMap ? $indent + $this->indentation : $indent + 2, $flags);
+
+                        if (is_scalar($value->getValue())) {
+                            $output .= "\n";
+                        }
                     }
 
                     continue;

src/Symfony/Component/Yaml/Tests/DumperTest.php

@@ -459,6 +459,23 @@ YAML;
         $this->assertSame($expected, $yaml);
     }
 
+    public function testDumpingNotInlinedScalarTaggedValue()
+    {
+        $data = [
+            'user1' => new TaggedValue('user', 'jane'),
+            'user2' => new TaggedValue('user', 'john'),
+        ];
+        $expected = <<<YAML
+user1: !user
+    jane
+user2: !user
+    john
+
+YAML;
+
+        $this->assertSame($expected, $this->dumper->dump($data, 2));
+    }
+
     public function testDumpMultiLineStringAsScalarBlock()
     {
         $data = [