[PATCH 4 of 4] HTTP/2: don't send SETTINGS ACK before already queued DATA frames

[Piotr Sikora]

# HG changeset patch
# User Piotr Sikora <piotrsikora at google.com>
# Date 1493067070 25200
#      Mon Apr 24 13:51:10 2017 -0700
# Node ID 26c9e95a73295a344d39ac5e6d62787d26989c82
# Parent  e00ba13ce421685981db6a98831409a234cc1e62
HTTP/2: don't send SETTINGS ACK before already queued DATA frames.

Previously, SETTINGS ACK was sent immediately upon receipt of SETTINGS
frame, before already queued DATA frames created using old SETTINGS.

This incorrect behavior was source of interoperability issues, because
peers rely on the fact that new SETTINGS are in effect after receiving
SETTINGS ACK.

Reported by Feng Li.

Signed-off-by: Piotr Sikora <piotrsikora at google.com>

diff -r e00ba13ce421 -r 26c9e95a7329 src/http/v2/ngx_http_v2.c
--- a/src/http/v2/ngx_http_v2.c
+++ b/src/http/v2/ngx_http_v2.c
@@ -2032,7 +2032,7 @@ ngx_http_v2_state_settings_params(ngx_ht
         return ngx_http_v2_connection_error(h2c, NGX_HTTP_V2_INTERNAL_ERROR);
     }
 
-    ngx_http_v2_queue_blocked_frame(h2c, frame);
+    ngx_http_v2_queue_ordered_frame(h2c, frame);
 
     if (window_delta) {
         if (ngx_http_v2_adjust_windows(h2c, window_delta) != NGX_OK) {
diff -r e00ba13ce421 -r 26c9e95a7329 src/http/v2/ngx_http_v2.h
--- a/src/http/v2/ngx_http_v2.h
+++ b/src/http/v2/ngx_http_v2.h
@@ -261,6 +261,15 @@ ngx_http_v2_queue_blocked_frame(ngx_http
 }
 
 
+static ngx_inline void
+ngx_http_v2_queue_ordered_frame(ngx_http_v2_connection_t *h2c,
+    ngx_http_v2_out_frame_t *frame)
+{
+    frame->next = h2c->last_out;
+    h2c->last_out = frame;
+}
+
+
 void ngx_http_v2_init(ngx_event_t *rev);
 void ngx_http_v2_request_headers_init(void);