From: Sergey Kandaurov <pluknet@nginx.com>
Date: Fri, 25 Sep 2026 15:34:44 +0000 (+0000)
Subject: HTTP/2: do not block the output queue on trailers
X-Git-Url: https://git.kaiwu.me/?a=commitdiff_plain;h=867aefddbce17efd0e1e6ab1bfd5522e6e4cdc7d;p=nginx.git

HTTP/2: do not block the output queue on trailers

Unlike response headers, trailers are queued along with the stream data.
Blocking the queue on them would hold back every frame queued later,
including higher priority streams.

Also, this way unsent trailers are discarded along with the stream data
when the stream is reset.
---

diff --git a/src/http/v2/ngx_http_v2_filter_module.c b/src/http/v2/ngx_http_v2_filter_module.c
index c82cbbddf..61e637137 100644
--- a/src/http/v2/ngx_http_v2_filter_module.c
+++ b/src/http/v2/ngx_http_v2_filter_module.c
@@ -1227,6 +1227,7 @@ ngx_http_v2_send_chain(ngx_connection_t *fc, ngx_chain_t *in, off_t limit)
             }
 
             if (trailers != NGX_HTTP_V2_NO_TRAILERS) {
+                trailers->blocked = 0;
                 cl->buf->last_buf = 0;
             }
         }
@@ -1732,7 +1733,9 @@ ngx_http_v2_filter_cleanup(void *data)
         if (frame->stream == stream && !frame->blocked) {
             *fn = frame->next;
 
-            window += frame->length;
+            if (frame->handler == ngx_http_v2_data_frame_handler) {
+                window += frame->length;
+            }
 
             if (--stream->queued == 0) {
                 break;