Merge branch '2.3' into 2.7

* 2.3:
  bumped Symfony version to 2.3.40
  set s-maxage only if all responses are cacheable
  updated VERSION for 2.3.39
  update CONTRIBUTORS for 2.3.39
  updated CHANGELOG for 2.3.39
  Improved the "branch" row of the PR table
  Fix typos #18090 1. PHPs session design to PHP's session design 2. Symfony HttpKernel offers to Symfony's HttpKernel offers 3. in which case it it should to in which case it should
  Fix for Isssue #18091
  replace perfom by perform
  minor #18088 Fix typo for profiler

Author: fabpot

HttpCache/ResponseCacheStrategy.php

@@ -32,6 +32,7 @@ class ResponseCacheStrategy implements ResponseCacheStrategyInterface
     private $embeddedResponses = 0;
     private $ttls = array();
     private $maxAges = array();
+    private $isNotCacheableResponseEmbedded = false;
 
     /**
      * {@inheritdoc}
@@ -41,8 +42,13 @@ public function add(Response $response)
         if ($response->isValidateable()) {
             $this->cacheable = false;
         } else {
+            $maxAge = $response->getMaxAge();
             $this->ttls[] = $response->getTtl();
-            $this->maxAges[] = $response->getMaxAge();
+            $this->maxAges[] = $maxAge;
+
+            if (null === $maxAge) {
+                $this->isNotCacheableResponseEmbedded = true;
+            }
         }
 
         ++$this->embeddedResponses;
@@ -76,7 +82,9 @@ public function update(Response $response)
         $this->ttls[] = $response->getTtl();
         $this->maxAges[] = $response->getMaxAge();
 
-        if (null !== $maxAge = min($this->maxAges)) {
+        if ($this->isNotCacheableResponseEmbedded) {
+            $response->headers->removeCacheControlDirective('s-maxage');
+        } elseif (null !== $maxAge = min($this->maxAges)) {
             $response->setSharedMaxAge($maxAge);
             $response->headers->set('Age', $maxAge - min($this->ttls));
         }

Tests/HttpCache/ResponseCacheStrategyTest.php

@@ -0,0 +1,77 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * This code is partially based on the Rack-Cache library by Ryan Tomayko,
+ * which is released under the MIT license.
+ * (based on commit 02d2b48d75bcb63cf1c0c7149c077ad256542801)
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpKernel\Tests\HttpCache;
+
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\HttpCache\EsiResponseCacheStrategy;
+
+class EsiResponseCacheStrategyTest extends \PHPUnit_Framework_TestCase
+{
+    public function testMinimumSharedMaxAgeWins()
+    {
+        $cacheStrategy = new EsiResponseCacheStrategy();
+
+        $response1 = new Response();
+        $response1->setSharedMaxAge(60);
+        $cacheStrategy->add($response1);
+
+        $response2 = new Response();
+        $response2->setSharedMaxAge(3600);
+        $cacheStrategy->add($response2);
+
+        $response = new Response();
+        $response->setSharedMaxAge(86400);
+        $cacheStrategy->update($response);
+
+        $this->assertSame('60', $response->headers->getCacheControlDirective('s-maxage'));
+    }
+
+    public function testSharedMaxAgeNotSetIfNotSetInAnyEmbeddedRequest()
+    {
+        $cacheStrategy = new EsiResponseCacheStrategy();
+
+        $response1 = new Response();
+        $response1->setSharedMaxAge(60);
+        $cacheStrategy->add($response1);
+
+        $response2 = new Response();
+        $cacheStrategy->add($response2);
+
+        $response = new Response();
+        $response->setSharedMaxAge(86400);
+        $cacheStrategy->update($response);
+
+        $this->assertFalse($response->headers->hasCacheControlDirective('s-maxage'));
+    }
+
+    public function testSharedMaxAgeNotSetIfNotSetInMasterRequest()
+    {
+        $cacheStrategy = new EsiResponseCacheStrategy();
+
+        $response1 = new Response();
+        $response1->setSharedMaxAge(60);
+        $cacheStrategy->add($response1);
+
+        $response2 = new Response();
+        $response2->setSharedMaxAge(3600);
+        $cacheStrategy->add($response2);
+
+        $response = new Response();
+        $cacheStrategy->update($response);
+
+        $this->assertFalse($response->headers->hasCacheControlDirective('s-maxage'));
+    }
+}