Hey Valentin,
> + h = ngx_list_push(&r->headers_in.headers);
> + if (h == NULL) {
> + return ngx_http_v2_connection_error(h2c, NGX_HTTP_V2_INTERNAL_ERROR);
This needs to wrap, since the line is too long.
Otherwise, looks good, thanks!
Best regards,
Piotr Sikora