symfony · mpdude · Mar 17, 2017 · Mar 17, 2017 · Mar 17, 2017 · Mar 17, 2017
diff --git a/src/Symfony/Component/HttpFoundation/Response.php b/src/Symfony/Component/HttpFoundation/Response.php
@@ -530,7 +530,7 @@ public function isCacheable()
             return false;
         }
 
-        return $this->isValidateable() || $this->isFresh();
+        return $this->isValidateable() || $this->isExpirable();
     }
 
     /**
@@ -547,6 +547,19 @@ public function isFresh()
         return $this->getTtl() > 0;
     }
 
+    /**
+     * Returns true if the response includes headers that indicate time-based
+     * content expiration.
+     *
+     * @return bool true if the response expires when it reaches a particular age, false otherwise.
+     */
+    public function isExpirable()
+    {
+        return $this->headers->hasCacheControlDirective('s-maxage')
+            || $this->headers->hasCacheControlDirective('max-age')
+            || $this->headers->has('expires');
+    }
+
     /**
      * Returns true if the response includes headers that can be used to validate
      * the response with the origin server using a conditional GET request.

diff --git a/src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php b/src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php
@@ -258,6 +258,24 @@ public function testIsValidateable()
         $this->assertFalse($response->isValidateable(), '->isValidateable() returns false when no validator is present');
     }
 
+    public function testIsExpirable()
+    {
+        $response = new Response('', 200);
+        $response->setSharedMaxAge(100);
+        $this->assertTrue($response->isExpirable(), '->isExpirable() returns true if a shared-maxage is set');
+
+        $response = new Response('', 200);
+        $response->setMaxAge(100);
+        $this->assertTrue($response->isExpirable(), '->isExpirable() returns true if a maxage is set');
+
+        $response = new Response('', 200);
+        $response->setExpires($this->createDateTimeOneHourLater());
+        $this->assertTrue($response->isExpirable(), '->isExpirable() returns true if an Expires date present');
+
+        $response = new Response();
+        $this->assertFalse($response->isExpirable(), '->isExpirable() returns false when no max-age or expire date is present');
+    }
+
     public function testGetDate()
     {
         $oneHourAgo = $this->createDateTimeOneHourAgo();
@@ -304,6 +322,14 @@ public function testGetMaxAge()
         $this->assertNull($response->getMaxAge(), '->getMaxAge() returns null if no freshness information available');
     }
 
+    public function testMaxAge0IsStillCacheable()
+    {
+        $response = new Response();
+        $response->setSharedMaxAge(0);
+
+        $this->assertTrue($response->isCacheable(), '->isCacheable() returns true even if the Response must always be revalidated');
+    }
+
     public function testSetSharedMaxAge()
     {
         $response = new Response();

diff --git a/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTest.php b/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTest.php
@@ -586,6 +586,31 @@ public function testHitsCachedResponseWithSMaxAgeDirective()
         $this->assertEquals('Hello World', $this->response->getContent());
     }
 
+    public function testCachesResponseWithSMaxAge0ButRevalidatesIt()
+    {
+        $this->setNextResponse(200, array('Cache-Control' => 's-maxage=0'), 'Hello World');
+
+        $this->request('GET', '/');
+        $this->assertHttpKernelIsCalled();
+        $this->assertEquals(200, $this->response->getStatusCode());
+        $this->assertTraceContains('miss');
+        $this->assertTraceContains('store');
+        $this->assertEquals(0, $this->response->getAge());
+        $this->assertEquals('Hello World', $this->response->getContent());
+
+        sleep(2);
+
+        $this->setNextResponse(304, array('Cache-Control' => 's-maxage=0'));
+
+        $this->request('GET', '/');
+        $this->assertHttpKernelIsCalled();
+        $this->assertEquals(200, $this->response->getStatusCode());
+        $this->assertTraceContains('stale');
+        $this->assertTraceContains('valid');
+        $this->assertEquals(0, $this->response->getAge());
+        $this->assertEquals('Hello World', $this->response->getContent());
+    }
+
     public function testAssignsDefaultTtlWhenResponseHasNoFreshnessInformation()
     {
         $this->setNextResponse();

diff --git a/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTestCase.php b/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTestCase.php
@@ -13,6 +13,7 @@
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\HttpCache\Esi;
 use Symfony\Component\HttpKernel\HttpCache\HttpCache;
 use Symfony\Component\HttpKernel\HttpCache\Store;
@@ -25,6 +26,8 @@ class HttpCacheTestCase extends TestCase
     protected $caches;
     protected $cacheConfig;
     protected $request;
+
+    /** @var Response */
     protected $response;
     protected $responses;
     protected $catch;

diff --git a/src/Symfony/Component/HttpKernel/composer.json b/src/Symfony/Component/HttpKernel/composer.json
@@ -18,7 +18,7 @@
     "require": {
         "php": ">=5.3.9",
         "symfony/event-dispatcher": "^2.6.7|~3.0.0",
-        "symfony/http-foundation": "~2.7.20|~2.8.13|~3.1.6",
+        "symfony/http-foundation": "^2.8.19|~3.1.6",
         "symfony/debug": "^2.6.2",
         "psr/log": "~1.0"
     },