bug #28083 Remove the Expires header when calling Response::expire() …

…(javiereguiluz)

This PR was merged into the 2.8 branch.

Discussion
----------

Remove the Expires header when calling Response::expire()

| Q             | A
| ------------- | ---
| Branch?       | 2.8
| Bug fix?      | yes
| New feature?  | no <!-- don't forget to update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no <!-- don't forget to update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | #13341   <!-- #-prefixed issue number(s), if any -->
| License       | MIT
| Doc PR        | -

Commits
-------

ac0cd15 Remove the Expires header when calling Response::expire()

src/Symfony/Component/HttpFoundation/Response.php

@@ -675,6 +675,7 @@ public function expire()
     {
         if ($this->isFresh()) {
             $this->headers->set('Age', $this->getMaxAge());
+            $this->headers->remove('Expires');
         }
 
         return $this;

src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php

@@ -362,6 +362,11 @@ public function testExpire()
         $response->headers->set('Expires', -1);
         $response->expire();
         $this->assertNull($response->headers->get('Age'), '->expire() does not set the Age when the response is expired');
+
+        $response = new Response();
+        $response->headers->set('Expires', date(DATE_RFC2822, time() + 600));
+        $response->expire();
+        $this->assertNull($response->headers->get('Expires'), '->expire() removes the Expires header when the response is fresh');
     }
 
     public function testGetTtl()