Fix hydrating null value when field is nullable

Author: malarzm

lib/Doctrine/ODM/MongoDB/Hydrator/HydratorFactory.php

@@ -232,9 +232,13 @@ private function generateHydratorClass(ClassMetadata $class, $hydratorClassName,
                 $code .= sprintf(<<<EOF
 
         /** @Field(type="{$mapping['type']}") */
-        if (isset(\$data['%1\$s'])) {
+        if (isset(\$data['%1\$s']) || (! empty(\$this->class->fieldMappings['%2\$s']['nullable']) && array_key_exists('%1\$s', \$data))) {
             \$value = \$data['%1\$s'];
-            %3\$s
+            if (\$value !== null) {
+                %3\$s
+            } else {
+                \$return = null;
+            }
             \$this->class->reflFields['%2\$s']->setValue(\$document, \$return);
             \$hydratedData['%2\$s'] = \$return;
         }

tests/Doctrine/ODM/MongoDB/Tests/HydratorTest.php

@@ -13,6 +13,7 @@ public function testHydrator()
         $user = new HydrationClosureUser();
         $this->dm->getHydratorFactory()->hydrate($user, array(
             '_id' => 1,
+            'title' => null,
             'name' => 'jon',
             'birthdate' => new \DateTime('1961-01-01'),
             'referenceOne' => array('$id' => '1'),
@@ -31,6 +32,7 @@ public function testHydrator()
         ));
 
         $this->assertEquals(1, $user->id);
+        $this->assertSame(null, $user->title);
         $this->assertEquals('jon', $user->name);
         $this->assertInstanceOf('DateTime', $user->birthdate);
         $this->assertInstanceOf(__NAMESPACE__.'\HydrationClosureReferenceOne', $user->referenceOne);
@@ -49,6 +51,9 @@ class HydrationClosureUser
     /** @ODM\Id */
     public $id;
 
+    /** @ODM\Field(type="string", nullable=true) */
+    public $title = 'Mr.';
+
     /** @ODM\String */
     public $name;