Merge branch '3.4' into 4.3

* 3.4:
  chown and chgrp should also accept int as owner and group
  Fix RememberMe with null password
  [Validator] Fix plurals for sr_Latn (Serbian language written in latin script) validation messages
  [PhpUnitBridge][SymfonyTestsListenerTrait] Remove some unneeded code
  fix PHP const mapping keys using the inline notation
  Fix that no-cache requires positive validation with the origin, even for fresh responses

Author: fabpot

HttpCache/HttpCache.php

@@ -353,6 +353,10 @@ protected function lookup(Request $request, $catch = false)
             return $this->validate($request, $entry, $catch);
         }
 
+        if ($entry->headers->hasCacheControlDirective('no-cache')) {
+            return $this->validate($request, $entry, $catch);
+        }
+
         $this->record($request, 'fresh');
 
         $entry->headers->set('Age', $entry->getAge());

Tests/HttpCache/HttpCacheTest.php

@@ -443,6 +443,22 @@ public function testCachesResponsesWithExplicitNoCacheDirective()
         $this->assertTrue($this->response->headers->has('Age'));
     }
 
+    public function testRevalidatesResponsesWithNoCacheDirectiveEvenIfFresh()
+    {
+        $this->setNextResponse(200, ['Cache-Control' => 'public, no-cache, max-age=10', 'ETag' => 'some-etag'], 'OK');
+        $this->request('GET', '/'); // warm the cache
+
+        sleep(5);
+
+        $this->setNextResponse(304, ['Cache-Control' => 'public, no-cache, max-age=10', 'ETag' => 'some-etag']);
+        $this->request('GET', '/');
+
+        $this->assertHttpKernelIsCalled(); // no-cache -> MUST have revalidated at origin
+        $this->assertTraceContains('valid');
+        $this->assertEquals('OK', $this->response->getContent());
+        $this->assertEquals(0, $this->response->getAge());
+    }
+
     public function testCachesResponsesWithAnExpirationHeader()
     {
         $time = \DateTime::createFromFormat('U', time() + 5);