Guzzle updated from version 3.1 to 3.7

The Guzzle library has been updated to version 3.7.

One of the relevant changes is how the final location is accessed after a redirect.

Before

// Update the feed URL in case of a 301 redirect.
if ($previous_response = $response->getPreviousResponse()) {
  if ($previous_response->getStatusCode() == 301 && $location = $previous_response->getLocation()) {
    $feed->url->value = $location;
  }
}

After

// Update the feed URL in case of a 301 redirect.
if ($response->getEffectiveUrl() != $feed->url->value) {
  $feed->url->value = $response->getEffectiveUrl();
}

Another example, when using Last-Modified or similar headers in the Request, the response now needs to be checked for a HTTP 304 Not Modified explicitly and handled accordingly.

// Given code like this.
$request->addHeader('If-None-Match', $feed->etag->value);
$request->addHeader('If-Modified-Since', gmdate(DATE_RFC1123, $feed->modified->value));

// The status code now needs to be checked for 304 and handled.
if ($response->getStatusCode() == 304) {
  return FALSE;
}

See the the official upgrading documentation for all changes: UPGRADING.md