bug #11220 [Components][Serializer] optional constructor arguments can be omitted during the denormalization process (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
----------

[Components][Serializer] optional constructor arguments can be omitted during the denormalization process

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #10499
| License       | MIT
| Doc PR        |

Commits
-------

5bb2345 [Components][Serializer] optional constructor arguments can be omitted during the denormalization process

src/Symfony/Component/Serializer/Normalizer/GetSetMethodNormalizer.php

@@ -128,7 +128,9 @@ class GetSetMethodNormalizer extends SerializerAwareNormalizer implements Normal
                     $params[] = $data[$paramName];
                     // don't run set for a parameter passed to the constructor
                     unset($data[$paramName]);
-                } elseif (!$constructorParameter->isOptional()) {
+                } elseif ($constructorParameter->isOptional()) {
+                    $params[] = $constructorParameter->getDefaultValue();
+                } else {
                     throw new RuntimeException(
                         'Cannot create an instance of '.$class.
                         ' from serialized data because its constructor requires '.

src/Symfony/Component/Serializer/Tests/Normalizer/GetSetMethodNormalizerTest.php

@@ -86,6 +86,16 @@ class GetSetMethodNormalizerTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('bar', $obj->getBar());
     }
 
+    public function testConstructorDenormalizeWithMissingOptionalArgument()
+    {
+        $obj = $this->normalizer->denormalize(
+            array('foo' => 'test', 'baz' => array(1, 2, 3)),
+            __NAMESPACE__.'\GetConstructorOptionalArgsDummy', 'any');
+        $this->assertEquals('test', $obj->getFoo());
+        $this->assertEquals(array(), $obj->getBar());
+        $this->assertEquals(array(1, 2, 3), $obj->getBaz());
+    }
+
     /**
      * @dataProvider provideCallbacks
      */
@@ -263,3 +273,37 @@ class GetConstructorDummy
         throw new \RuntimeException("Dummy::otherMethod() should not be called");
     }
 }
+
+class GetConstructorOptionalArgsDummy
+{
+    protected $foo;
+    private $bar;
+    private $baz;
+
+    public function __construct($foo, $bar = array(), $baz = array())
+    {
+        $this->foo = $foo;
+        $this->bar = $bar;
+        $this->baz = $baz;
+    }
+
+    public function getFoo()
+    {
+        return $this->foo;
+    }
+
+    public function getBar()
+    {
+        return $this->bar;
+    }
+
+    public function getBaz()
+    {
+        return $this->baz;
+    }
+
+    public function otherMethod()
+    {
+        throw new \RuntimeException("Dummy::otherMethod() should not be called");
+    }
+}