Use error code CANCEL to reset pushed reserved stream from remote

lib/nghttp2_session.c

@@ -4196,9 +4196,8 @@ int nghttp2_session_on_push_promise_received(nghttp2_session *session,
             session, frame, NGHTTP2_ERR_PROTO, "PUSH_PROMISE: stream in idle");
       }
     }
-    rv = nghttp2_session_add_rst_stream(session,
-                                        frame->push_promise.promised_stream_id,
-                                        NGHTTP2_REFUSED_STREAM);
+    rv = nghttp2_session_add_rst_stream(
+        session, frame->push_promise.promised_stream_id, NGHTTP2_CANCEL);
     if (rv != 0) {
       return rv;
     }

tests/nghttp2_session_test.c

@@ -2632,7 +2632,7 @@ void test_nghttp2_session_on_push_promise_received(void) {
   item = nghttp2_session_get_next_ob_item(session);
   CU_ASSERT(NGHTTP2_RST_STREAM == item->frame.hd.type);
   CU_ASSERT(6 == item->frame.hd.stream_id);
-  CU_ASSERT(NGHTTP2_REFUSED_STREAM == item->frame.rst_stream.error_code);
+  CU_ASSERT(NGHTTP2_CANCEL == item->frame.rst_stream.error_code);
   CU_ASSERT(0 == nghttp2_session_send(session));
 
   /* Attempt to PUSH_PROMISE against non-existent stream */
@@ -2806,7 +2806,7 @@ void test_nghttp2_session_on_push_promise_received(void) {
   item = nghttp2_session_get_next_ob_item(session);
 
   CU_ASSERT(NGHTTP2_RST_STREAM == item->frame.hd.type);
-  CU_ASSERT(NGHTTP2_REFUSED_STREAM == item->frame.rst_stream.error_code);
+  CU_ASSERT(NGHTTP2_CANCEL == item->frame.rst_stream.error_code);
 
   nghttp2_frame_push_promise_free(&frame.push_promise, mem);
   nghttp2_session_del(session);