[nginx] QUIC: reset qc->error to zero again.

[noreply at nginx.com]

details:   https://github.com/nginx/nginx/commit/5d7fd4a7e3025e8600bb029742a0a28bf4ca9eec
branches:  master
commit:    5d7fd4a7e3025e8600bb029742a0a28bf4ca9eec
user:      Sergey Kandaurov <pluknet at nginx.com>
date:      Wed, 14 May 2025 23:33:00 +0400
description:
QUIC: reset qc->error to zero again.

Following the previous change that removed posting a close event
in OpenSSL compat layer, now ngx_quic_close_connection() is always
called on error path with either NGX_ERROR or qc->error set.

This allows to remove a special value -1 served as a missing error,
which simplifies the code.  Partially reverts d3fb12d77.

Also, this improves handling of the draining connection state, which
consists of posting a close event with NGX_OK and no qc->error set,
where it was previously converted to NGX_QUIC_ERR_INTERNAL_ERROR.
Notably, this is rather a cosmetic fix, because drained connections
do not send any packets including CONNECTION_CLOSE, and qc->error
is not otherwise used.

---
 src/event/quic/ngx_event_quic.c     | 6 +++---
 src/event/quic/ngx_event_quic_ssl.c | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/event/quic/ngx_event_quic.c b/src/event/quic/ngx_event_quic.c
index a4ad85d56..9f968d5fb 100644
--- a/src/event/quic/ngx_event_quic.c
+++ b/src/event/quic/ngx_event_quic.c
@@ -72,7 +72,7 @@ ngx_quic_connstate_dbg(ngx_connection_t *c)
 
     if (qc) {
 
-        if (qc->error != (ngx_uint_t) -1) {
+        if (qc->error) {
             p = ngx_slprintf(p, last, "%s", qc->error_app ? " app" : "");
             p = ngx_slprintf(p, last, " error:%ui", qc->error);
 
@@ -520,7 +520,7 @@ ngx_quic_close_connection(ngx_connection_t *c, ngx_int_t rc)
              *  to terminate the connection immediately.
              */
 
-            if (qc->error == (ngx_uint_t) -1) {
+            if (qc->error == 0 && rc == NGX_ERROR) {
                 qc->error = NGX_QUIC_ERR_INTERNAL_ERROR;
                 qc->error_app = 0;
             }
@@ -961,7 +961,7 @@ ngx_quic_handle_payload(ngx_connection_t *c, ngx_quic_header_t *pkt)
 
     qc = ngx_quic_get_connection(c);
 
-    qc->error = (ngx_uint_t) -1;
+    qc->error = 0;
     qc->error_reason = 0;
 
     c->log->action = "decrypting packet";
diff --git a/src/event/quic/ngx_event_quic_ssl.c b/src/event/quic/ngx_event_quic_ssl.c
index dd7ee3702..5b897bdb6 100644
--- a/src/event/quic/ngx_event_quic_ssl.c
+++ b/src/event/quic/ngx_event_quic_ssl.c
@@ -415,7 +415,7 @@ ngx_quic_crypto_input(ngx_connection_t *c, ngx_chain_t *data,
 
     ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "SSL_do_handshake: %d", n);
 
-    if (qc->error != (ngx_uint_t) -1) {
+    if (qc->error) {
         return NGX_ERROR;
     }