Merge branch '4.4' into 5.2

* 4.4:
  [Serializer][Validator] Update some phpDoc relative to "getters"
  Update README.md
  [SecurityBundle] Empty line starting with dash under "access_control" causes all rules to be skipped
  [Cache] Apply NullAdapter as Null Object

src/Symfony/Bundle/SecurityBundle/DependencyInjection/SecurityExtension.php

@@ -208,6 +208,12 @@ class SecurityExtension extends Extension implements PrependExtensionInterface
                 $attributes[] = $this->createExpression($container, $access['allow_if']);
             }
 
+            $emptyAccess = 0 === \count(array_filter($access));
+
+            if ($emptyAccess) {
+                throw new InvalidConfigurationException('One or more access control items are empty. Did you accidentally add lines only containing a "-" under "security.access_control"?');
+            }
+
             $container->getDefinition('security.access_map')
                       ->addMethodCall('add', [$matcher, $attributes, $access['requires_channel']]);
         }

src/Symfony/Bundle/SecurityBundle/Tests/DependencyInjection/SecurityExtensionTest.php

@@ -432,6 +432,56 @@ class SecurityExtensionTest extends TestCase
         $this->assertEquals(new Reference('security.user.provider.concrete.second'), $container->getDefinition('security.authentication.switchuser_listener.foobar')->getArgument(1));
     }
 
+    public function testInvalidAccessControlWithEmptyRow()
+    {
+        $container = $this->getRawContainer();
+
+        $container->loadFromExtension('security', [
+            'providers' => [
+                'default' => ['id' => 'foo'],
+            ],
+            'firewalls' => [
+                'some_firewall' => [
+                    'pattern' => '/.*',
+                    'http_basic' => [],
+                ],
+            ],
+            'access_control' => [
+                [],
+                ['path' => '/admin', 'roles' => 'ROLE_ADMIN'],
+            ],
+        ]);
+
+        $this->expectException(InvalidConfigurationException::class);
+        $this->expectExceptionMessage('One or more access control items are empty. Did you accidentally add lines only containing a "-" under "security.access_control"?');
+        $container->compile();
+    }
+
+    public function testValidAccessControlWithEmptyRow()
+    {
+        $container = $this->getRawContainer();
+
+        $container->loadFromExtension('security', [
+            'providers' => [
+                'default' => ['id' => 'foo'],
+            ],
+            'firewalls' => [
+                'some_firewall' => [
+                    'pattern' => '/.*',
+                    'http_basic' => [],
+                ],
+            ],
+            'access_control' => [
+                ['path' => '^/login'],
+                ['path' => '^/', 'roles' => 'ROLE_USER'],
+            ],
+        ]);
+
+        $container->compile();
+
+        $this->assertTrue(true, 'extension throws an InvalidConfigurationException if there is one more more empty access control items');
+    }
+
     /**
      * @dataProvider provideEntryPointFirewalls
      */

src/Symfony/Component/Cache/Adapter/NullAdapter.php

@@ -112,7 +112,7 @@ class NullAdapter implements AdapterInterface, CacheInterface
      */
     public function save(CacheItemInterface $item)
     {
-        return false;
+        return true;
     }
 
     /**
@@ -122,7 +122,7 @@ class NullAdapter implements AdapterInterface, CacheInterface
      */
     public function saveDeferred(CacheItemInterface $item)
     {
-        return false;
+        return true;
     }
 
     /**
@@ -132,7 +132,7 @@ class NullAdapter implements AdapterInterface, CacheInterface
      */
     public function commit()
     {
-        return false;
+        return true;
     }
 
     /**

src/Symfony/Component/Cache/Tests/Adapter/NullAdapterTest.php

@@ -113,7 +113,7 @@ class NullAdapterTest extends TestCase
         $this->assertFalse($item->isHit());
         $this->assertNull($item->get(), "Item's value must be null when isHit is false.");
 
-        $this->assertFalse($adapter->save($item));
+        $this->assertTrue($adapter->save($item));
     }
 
     public function testDeferredSave()
@@ -124,7 +124,7 @@ class NullAdapterTest extends TestCase
         $this->assertFalse($item->isHit());
         $this->assertNull($item->get(), "Item's value must be null when isHit is false.");
 
-        $this->assertFalse($adapter->saveDeferred($item));
+        $this->assertTrue($adapter->saveDeferred($item));
     }
 
     public function testCommit()
@@ -135,7 +135,7 @@ class NullAdapterTest extends TestCase
         $this->assertFalse($item->isHit());
         $this->assertNull($item->get(), "Item's value must be null when isHit is false.");
 
-        $this->assertFalse($adapter->saveDeferred($item));
-        $this->assertFalse($this->createCachePool()->commit());
+        $this->assertTrue($adapter->saveDeferred($item));
+        $this->assertTrue($this->createCachePool()->commit());
     }
 }

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

@@ -61,7 +61,7 @@ class GetSetMethodNormalizer extends AbstractObjectNormalizer
     }
 
     /**
-     * Checks if the given class has any get{Property} method.
+     * Checks if the given class has any getter method.
      */
     private function supports(string $class): bool
     {
@@ -77,7 +77,7 @@ class GetSetMethodNormalizer extends AbstractObjectNormalizer
     }
 
     /**
-     * Checks if a method's name is get.* or is.*, and can be called without parameters.
+     * Checks if a method's name matches /^(get|is|has).+$/ and can be called non-statically without parameters.
      */
     private function isGetMethod(\ReflectionMethod $method): bool
     {

src/Symfony/Component/Validator/Mapping/ClassMetadata.php

@@ -264,7 +264,7 @@ class ClassMetadata extends GenericMetadata implements ClassMetadataInterface
      * Adds a constraint to the getter of the given property.
      *
      * The name of the getter is assumed to be the name of the property with an
-     * uppercased first letter and either the prefix "get" or "is".
+     * uppercased first letter and the prefix "get", "is" or "has".
      *
      * @return $this
      */

src/Symfony/Component/Validator/Mapping/GetterMetadata.php

@@ -18,7 +18,7 @@ use Symfony\Component\Validator\Exception\ValidatorException;
  * method.
  *
  * A property getter is any method that is equal to the property's name,
- * prefixed with either "get" or "is". That method will be used to access the
+ * prefixed with "get", "is" or "has". That method will be used to access the
  * property's value.
  *
  * The getter will be invoked by reflection, so the access of private and