HTTP/2: workaround for clients which fail on table size updates.

There are clients which cannot handle HPACK's dynamic table size updates
as added in 12cadc4669a7 (1.13.6).  Notably, old versions of OkHttp library
are known to fail on it (ticket #1397).

This change makes it possible to work with such clients by only sending
dynamic table size updates in response to SETTINGS_HEADER_TABLE_SIZE.  As
a downside, clients which do not use SETTINGS_HEADER_TABLE_SIZE will
continue to maintain default 4k table.

diff --git a/src/http/v2/ngx_http_v2.c b/src/http/v2/ngx_http_v2.c
index 09737700a6d383c95f782452935b41feb7e49b85..e777019299ff8c9b22f5271841a5c9f265f9b901 100644 (file)
--- a/src/http/v2/ngx_http_v2.c
+++ b/src/http/v2/ngx_http_v2.c
@@ -270,8 +270,6 @@ ngx_http_v2_init(ngx_event_t *rev)
 
     h2c->frame_size = NGX_HTTP_V2_DEFAULT_FRAME_SIZE;
 
-    h2c->table_update = 1;
-
     h2scf = ngx_http_get_module_srv_conf(hc->conf_ctx, ngx_http_v2_module);
 
     h2c->concurrent_pushes = h2scf->concurrent_pushes;
@@ -2075,6 +2073,11 @@ ngx_http_v2_state_settings_params(ngx_http_v2_connection_t *h2c, u_char *pos,
             h2c->concurrent_pushes = ngx_min(value, h2scf->concurrent_pushes);
             break;
 
+        case NGX_HTTP_V2_HEADER_TABLE_SIZE_SETTING:
+
+            h2c->table_update = 1;
+            break;
+
         default:
             break;
         }