The forum atom/rss feeds ignore the If-Modified-Since header and always send a new response. Feed readers and javascript clients requires the If-Modified-Since header to return http status 304 Not Modified when the data hasn't changed.

 

Adding this code to \phpbb\feed\controller\feed.php at lines 399-402 fixed the issue:

if ($response->isNotModified($this->request))

{ $response->setNotModified(); }

 

I also had another issues using the atom feed from the browser since phpbb doesn't include the "Access-Control-Allow-Origin" header with the atom response.

Adding this code to \phpbb\feed\controller\feed.php at line 389 fixed the issue:

$response->headers->set('Access-Control-Allow-Origin', '*');

 

There should probably be ACP some options to control the list of domains for the ACAO headers.

 

 

Thanks

dmex