Merge branch '2.8' into 3.1

* 2.8:
  [FrameworkBundle] Check for class existence before is_subclass_of
  Update GroupSequence.php
  Code enhancement and cleanup
  [Form] Fix transformer tests after the ICU update
  [DI] Add anti-regression test
  Revert "minor #19689 [DI] Cleanup array_key_exists (ro0NL)"
  bumped Symfony version to 2.8.11
  updated VERSION for 2.8.10
  updated CHANGELOG for 2.8.10
  [BrowserKit] Fix cookie expiration on 32 bit systems
  bumped Symfony version to 2.7.18
  updated VERSION for 2.7.17
  update CONTRIBUTORS for 2.7.17
  updated CHANGELOG for 2.7.17
  Update misleading comment about RFC4627

Author: nicolas-grekas

Compiler/ServiceReferenceGraphEdge.php

@@ -39,7 +39,7 @@ public function __construct(ServiceReferenceGraphNode $sourceNode, ServiceRefere
     /**
      * Returns the value of the edge.
      *
-     * @return ServiceReferenceGraphNode
+     * @return string
      */
     public function getValue()
     {

Tests/ContainerTest.php

@@ -208,6 +208,18 @@ public function testGetCircularReference()
         }
     }
 
+    /**
+     * @expectedException \Symfony\Component\DependencyInjection\Exception\RuntimeException
+     * @expectedExcepionMessage You have requested a synthetic service ("request"). The DIC does not know how to construct this service.
+     */
+    public function testGetSyntheticServiceAlwaysThrows()
+    {
+        require_once __DIR__.'/Fixtures/php/services9.php';
+
+        $container = new \ProjectServiceContainer();
+        $container->get('request', ContainerInterface::NULL_ON_INVALID_REFERENCE);
+    }
+
     public function testHas()
     {
         $sc = new ProjectServiceContainer();

Tests/Dumper/PhpDumperTest.php

@@ -189,7 +189,7 @@ public function testConflictingMethodsWithParent()
 
     /**
      * @dataProvider provideInvalidFactories
-     * @expectedException Symfony\Component\DependencyInjection\Exception\RuntimeException
+     * @expectedException \Symfony\Component\DependencyInjection\Exception\RuntimeException
      * @expectedExceptionMessage Cannot dump definition
      */
     public function testInvalidFactories($factory)