[PATCH 01 of 10] QUIC: treat qc->error == -1 as a missing error

[Roman Arutyunyan]

# HG changeset patch
# User Roman Arutyunyan <arut at nginx.com>
# Date 1662539835 -14400
#      Wed Sep 07 12:37:15 2022 +0400
# Branch quic
# Node ID 48645c5397a3f178286bcd108748c140adccc8a5
# Parent  f9d7930d0eedae28defd0803cb95dc8ab68e56b3
QUIC: treat qc->error == -1 as a missing error.

Previously, zero was used for this purpose.  However, NGX_QUIC_ERR_NO_ERROR is
zero too.  As a result, NGX_QUIC_ERR_NO_ERROR was changed to
NGX_QUIC_ERR_INTERNAL_ERROR when closing a QUIC connection.

diff --git a/src/event/quic/ngx_event_quic.c b/src/event/quic/ngx_event_quic.c
--- a/src/event/quic/ngx_event_quic.c
+++ b/src/event/quic/ngx_event_quic.c
@@ -73,7 +73,7 @@ ngx_quic_connstate_dbg(ngx_connection_t 
 
     if (qc) {
 
-        if (qc->error) {
+        if (qc->error != (ngx_uint_t) -1) {
             p = ngx_slprintf(p, last, "%s", qc->error_app ? " app" : "");
             p = ngx_slprintf(p, last, " error:%ui", qc->error);
 
@@ -523,7 +523,7 @@ ngx_quic_close_connection(ngx_connection
                 qc->error = NGX_QUIC_ERR_NO_ERROR;
 
             } else {
-                if (qc->error == 0 && !qc->error_app) {
+                if (qc->error == (ngx_uint_t) -1 && !qc->error_app) {
                     qc->error = NGX_QUIC_ERR_INTERNAL_ERROR;
                 }
 
@@ -939,7 +939,7 @@ ngx_quic_handle_payload(ngx_connection_t
 
     qc = ngx_quic_get_connection(c);
 
-    qc->error = 0;
+    qc->error = (ngx_uint_t) -1;
     qc->error_reason = 0;
 
     c->log->action = "decrypting packet";