Fix Expires when the header is -1

Author: dlsniper

src/Symfony/Component/HttpFoundation/HeaderBag.php

@@ -235,6 +235,14 @@ public function getDate($key, \DateTime $default = null)
  return $default;
  }
 
+ if (-1 === $value) {
+ /**
+ * Since we need to return a valid date time a older date has been chosen
+ * https://github.com/symfony/symfony/pull/6471#discussion_r2527156
+ */
+ $value = 'Sat, 01 Jan 00 00:00:00 +0000';
+ }
+
  if (false === $date = \DateTime::createFromFormat(DATE_RFC2822, $value)) {
  throw new \RuntimeException(sprintf('The %s HTTP header is not parseable (%s).', $key, $value));
  }

src/Symfony/Component/HttpFoundation/Response.php

@@ -693,6 +693,10 @@ public function getMaxAge()
  }
 
  if (null !== $this->getExpires()) {
+ if (!$this->getExpires() instanceof \DateTime) {
+ return 0;
+ }
+
  return $this->getExpires()->format('U') - $this->getDate()->format('U');
  }
 

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

@@ -164,6 +164,11 @@ public function testGetMaxAge()
  $response->headers->set('Expires', $this->createDateTimeOneHourLater()->format(DATE_RFC2822));
  $this->assertEquals(3600, $response->getMaxAge(), '->getMaxAge() falls back to Expires when no max-age or s-maxage directive present');
 
+ $response = new Response();
+ $response->headers->set('Cache-Control', 'must-revalidate');
+ $response->headers->set('Expires', -1);
+ $this->assertEquals('Sat, 01 Jan 00 00:00:00 +0000', $response->getExpires()->format(DATE_RFC822));
+
  $response = new Response();
  $this->assertNull($response->getMaxAge(), '->getMaxAge() returns null if no freshness information available');
  }
@@ -214,6 +219,11 @@ public function testExpire()
  $response = new Response();
  $response->expire();
  $this->assertFalse($response->headers->has('Age'), '->expire() does nothing when the response does not include freshness information');
+
+ $response = new Response();
+ $response->headers->set('Expires', -1);
+ $response->expire();
+ $this->assertEquals(0, $response->headers->get('Age'), '->expire() does not set the Age to 0');
  }
 
  public function testGetTtl()