[HttpFoundation] HttpCache refresh stale responses containing an ETag

Author: Jonatan Männchen

HttpCache/HttpCache.php

@@ -600,6 +600,9 @@ protected function lock(Request $request, Response $entry)
      */
     protected function store(Request $request, Response $response)
     {
+        if (!$response->headers->has('Date')) {
+            $response->setDate(\DateTime::createFromFormat('U', time()));
+        }
         try {
             $this->store->write($request, $response);
 

Tests/HttpCache/HttpCacheTest.php

@@ -181,6 +181,31 @@ public function testRespondsWith304OnlyIfIfNoneMatchAndIfModifiedSinceBothMatch(
         $this->assertEquals(304, $this->response->getStatusCode());
     }
 
+    public function testIncrementsMaxAgeWhenNoDateIsSpecifiedEventWhenUsingETag()
+    {
+        $this->setNextResponse(
+            200,
+            array(
+                'ETag' => '1234',
+                'Cache-Control' => 'public, s-maxage=60',
+            )
+        );
+
+        $this->request('GET', '/');
+        $this->assertHttpKernelIsCalled();
+        $this->assertEquals(200, $this->response->getStatusCode());
+        $this->assertTraceContains('miss');
+        $this->assertTraceContains('store');
+
+        sleep(2);
+
+        $this->request('GET', '/');
+        $this->assertHttpKernelIsNotCalled();
+        $this->assertEquals(200, $this->response->getStatusCode());
+        $this->assertTraceContains('fresh');
+        $this->assertEquals(2, $this->response->headers->get('Age'));
+    }
+
     public function testValidatesPrivateResponsesCachedOnTheClient()
     {
         $this->setNextResponse(200, array(), '', function ($request, $response) {