From bb80139c3f2843ec627cf1761977753ae3e78c0d Mon Sep 17 00:00:00 2001
From: Bilal Amarni <bilal.amarni@gmail.com>
Date: Fri, 26 Apr 2013 14:05:25 +0200
Subject: [PATCH] [HttpCache] remove validation related headers when needed

---
 .../HttpCache/EsiResponseCacheStrategy.php    | 27 ++++++++++++------
 .../HttpKernel/HttpCache/HttpCache.php        |  4 +--
 .../Tests/HttpCache/HttpCacheTest.php         | 28 +++++++++++++++++++
 3 files changed, 49 insertions(+), 10 deletions(-)

diff --git a/src/Symfony/Component/HttpKernel/HttpCache/EsiResponseCacheStrategy.php b/src/Symfony/Component/HttpKernel/HttpCache/EsiResponseCacheStrategy.php
index c5ec81051fb3..6384af9660a8 100644
--- a/src/Symfony/Component/HttpKernel/HttpCache/EsiResponseCacheStrategy.php
+++ b/src/Symfony/Component/HttpKernel/HttpCache/EsiResponseCacheStrategy.php
@@ -29,13 +29,12 @@
 class EsiResponseCacheStrategy implements EsiResponseCacheStrategyInterface
 {
     private $cacheable = true;
+    private $embeddedResponses = 0;
     private $ttls = array();
     private $maxAges = array();
 
     /**
-     * Adds a Response.
-     *
-     * @param Response $response
+     * {@inheritdoc}
      */
     public function add(Response $response)
     {
@@ -45,26 +44,38 @@ public function add(Response $response)
             $this->ttls[] = $response->getTtl();
             $this->maxAges[] = $response->getMaxAge();
         }
+
+        $this->embeddedResponses++;
     }
 
     /**
-     * Updates the Response HTTP headers based on the embedded Responses.
-     *
-     * @param Response $response
+     * {@inheritdoc}
      */
     public function update(Response $response)
     {
-        // if we only have one Response, do nothing
-        if (1 === count($this->ttls)) {
+        // if we have no embedded Response, do nothing
+        if (0 === $this->embeddedResponses) {
             return;
         }
 
+        // Remove validation related headers in order to avoid browsers using
+        // their own cache, because some of the response content comes from
+        // at least one embedded response (which likely has a different caching strategy).
+        if ($response->isValidateable()) {
+            $response->setEtag(null);
+            $response->setLastModified(null);
+            $this->cacheable = false;
+        }
+
         if (!$this->cacheable) {
             $response->headers->set('Cache-Control', 'no-cache, must-revalidate');
 
             return;
         }
 
+        $this->ttls[] = $response->getTtl();
+        $this->maxAges[] = $response->getMaxAge();
+
         if (null !== $maxAge = min($this->maxAges)) {
             $response->setSharedMaxAge($maxAge);
             $response->headers->set('Age', $maxAge - min($this->ttls));
diff --git a/src/Symfony/Component/HttpKernel/HttpCache/HttpCache.php b/src/Symfony/Component/HttpKernel/HttpCache/HttpCache.php
index 69e938881449..3f37366a8489 100644
--- a/src/Symfony/Component/HttpKernel/HttpCache/HttpCache.php
+++ b/src/Symfony/Component/HttpKernel/HttpCache/HttpCache.php
@@ -205,10 +205,10 @@ public function handle(Request $request, $type = HttpKernelInterface::MASTER_REQ
         }
 
         if (null !== $this->esi) {
-            $this->esiCacheStrategy->add($response);
-
             if (HttpKernelInterface::MASTER_REQUEST === $type) {
                 $this->esiCacheStrategy->update($response);
+            } else {
+                $this->esiCacheStrategy->add($response);
             }
         }
 
diff --git a/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTest.php b/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTest.php
index 4cdd5f60e1f0..448ebc362bf3 100644
--- a/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTest.php
@@ -1075,4 +1075,32 @@ public function testXForwarderForHeaderForPassRequests()
 
         $this->assertEquals('10.0.0.1', $this->kernel->getBackendRequest()->headers->get('X-Forwarded-For'));
     }
+
+    public function testEsiCacheRemoveValidationHeadersIfEmbeddedResponses()
+    {
+        $time = new \DateTime;
+
+        $responses = array(
+            array(
+                'status'  => 200,
+                'body'    => '<esi:include src="/hey" />',
+                'headers' => array(
+                    'Surrogate-Control' => 'content="ESI/1.0"',
+                    'ETag' => 'hey',
+                    'Last-Modified' => $time->format(DATE_RFC2822),
+                ),
+            ),
+            array(
+                'status'  => 200,
+                'body'    => 'Hey!',
+                'headers' => array(),
+            ),
+        );
+
+        $this->setNextResponses($responses);
+
+        $this->request('GET', '/', array(), array(), true);
+        $this->assertNull($this->response->getETag());
+        $this->assertNull($this->response->getLastModified());
+    }
 }