From 1e38ceb1cd9152eacece8b398911af475e5b4880 Mon Sep 17 00:00:00 2001
From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Fri, 4 Apr 2014 20:23:46 +0900
Subject: [PATCH] Allow empty SETTINGS in upgrade

---
 lib/includes/nghttp2/nghttp2.h |  5 +----
 lib/nghttp2_session.c          | 15 +--------------
 tests/nghttp2_session_test.c   | 23 ++++-------------------
 3 files changed, 6 insertions(+), 37 deletions(-)

diff --git a/lib/includes/nghttp2/nghttp2.h b/lib/includes/nghttp2/nghttp2.h
index a53e334b..5f59f7cf 100644
--- a/lib/includes/nghttp2/nghttp2.h
+++ b/lib/includes/nghttp2/nghttp2.h
@@ -2061,10 +2061,7 @@ int nghttp2_session_terminate_session(nghttp2_session *session,
  * :enum:`NGHTTP2_ERR_INVALID_ARGUMENT`
  *     The |settings_payload| is badly formed.
  * :enum:`NGHTTP2_ERR_PROTO`
- *     The stream ID 1 is already used or closed; or is not available;
- *     or the |settings_payload| does not include both
- *     :enum:`NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS` and
- *     :enum:`NGHTTP2_SETTINGS_INITIAL_WINDOW_SIZE`.
+ *     The stream ID 1 is already used or closed; or is not available.
  */
 int nghttp2_session_upgrade(nghttp2_session *session,
                             const uint8_t *settings_payload,
diff --git a/lib/nghttp2_session.c b/lib/nghttp2_session.c
index b420c983..cb699dd4 100644
--- a/lib/nghttp2_session.c
+++ b/lib/nghttp2_session.c
@@ -5568,9 +5568,6 @@ int nghttp2_session_upgrade(nghttp2_session *session,
   nghttp2_settings_entry *iv;
   size_t niv;
   int rv;
-  int max_conn_val_seen = 0;
-  int ini_win_size_seen = 0;
-  size_t i;
   nghttp2_priority_spec pri_spec;
 
   if((!session->server && session->next_stream_id != 1) ||
@@ -5585,17 +5582,7 @@ int nghttp2_session_upgrade(nghttp2_session *session,
   if(rv != 0) {
     return rv;
   }
-  for(i = 0; i < niv; ++i) {
-    if(iv[i].settings_id == NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS) {
-      max_conn_val_seen = 1;
-    } else if(iv[i].settings_id == NGHTTP2_SETTINGS_INITIAL_WINDOW_SIZE) {
-      ini_win_size_seen = 1;
-    }
-  }
-  if(!max_conn_val_seen || !ini_win_size_seen) {
-    free(iv);
-    return NGHTTP2_ERR_PROTO;
-  }
+
   if(session->server) {
     memset(&frame.hd, 0, sizeof(frame.hd));
     frame.settings.iv = iv;
diff --git a/tests/nghttp2_session_test.c b/tests/nghttp2_session_test.c
index 0fc461d3..aece67ec 100644
--- a/tests/nghttp2_session_test.c
+++ b/tests/nghttp2_session_test.c
@@ -2578,29 +2578,14 @@ void test_nghttp2_session_upgrade(void)
                                                          &callbacks));
   nghttp2_session_del(session);
 
-  /* Check required settings */
-  iv[0].settings_id = NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS;
-  iv[0].value = 1;
+  /* Empty SETTINGS is OK */
   settings_payloadlen = nghttp2_pack_settings_payload(settings_payload,
                                                       sizeof(settings_payload),
-                                                      iv, 1);
+                                                      NULL, 0);
 
   nghttp2_session_client_new(&session, &callbacks, NULL);
-  CU_ASSERT(NGHTTP2_ERR_PROTO ==
-            nghttp2_session_upgrade(session, settings_payload,
-                                    settings_payloadlen, NULL));
-  nghttp2_session_del(session);
-
-  iv[0].settings_id = NGHTTP2_SETTINGS_INITIAL_WINDOW_SIZE;
-  iv[0].value = 4095;
-  settings_payloadlen = nghttp2_pack_settings_payload(settings_payload,
-                                                      sizeof(settings_payload),
-                                                      iv, 1);
-
-  nghttp2_session_client_new(&session, &callbacks, NULL);
-  CU_ASSERT(NGHTTP2_ERR_PROTO ==
-            nghttp2_session_upgrade(session, settings_payload,
-                                    settings_payloadlen, NULL));
+  CU_ASSERT(0 == nghttp2_session_upgrade(session, settings_payload,
+                                         settings_payloadlen, NULL));
   nghttp2_session_del(session);
 }