1.9.14 - Issues with disabled request buffering and HTTP/2

[n.dom]

Hello,

we have an issue with the newest nginx version 1.9.14. I am not sure if this
is a possible bug or a configuration problem.

We use nginx with disabled request buffering (proxy_request_buffering off)

We are currently using nginx 1.9.12 with HTTP/2 enabled. In this setup we
don't have any issues. I am aware of the fact, that request buffering cannot
be deactivated with HTTP/2 until version 1.9.13.

When updating to nginx 1.9.14, request buffering is disabled for HTTP/2 as
well.
In this case requests from some of our clients (we tested Firefox and
OkHttpClient) cannot load our web application anymore.
In the nginx error log we can see the following lines (non debug):
2016/04/07 14:20:49 [info] 20235#0: *3115050 client terminated stream 41
with status 1 while sending request to upstream, client: [......], server: ,
request: "POST [....]"

This only occurs when the client (Firefox and OkHttpClient) uses HTTP/2. We
cannot reproduce this issue with Google Chrome! Chrome works like a charm.

We also found out, that this issue seems only to occur within POST
requests.

When enabling proxy request buffering (proxy_request_buffering on), all
clients work as expected.

Is there anyone with similar issues when updating to the newest nginx
version 1.9.14?

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,266071,266071#msg-266071