# HG changeset patch
# User Vladimir Homutov <vl@nginx.com>
# Date 1634125713 -10800
# Node ID e2ec952dc295d199aec56f96c19a06557f99d249
# Parent  4b2d259bdadd24e4a3f88fd259b91aeba99c132c
QUIC: fixed removal of unused client IDs.

If client ID was never used, its refcount is zero.  To keep things simple,
the ngx_quic_unref_client_id() function is now aware of such IDs.

If client ID was used, the ngx_quic_replace_retired_client_id() function
is supposed to find all users and unref the ID, thus ngx_quic_unref_client_id()
should not be called after it.

diff --git a/src/event/quic/ngx_event_quic_connid.c b/src/event/quic/ngx_event_quic_connid.c
--- a/src/event/quic/ngx_event_quic_connid.c
+++ b/src/event/quic/ngx_event_quic_connid.c
@@ -183,9 +183,10 @@ retire:
             if (ngx_quic_replace_retired_client_id(c, cid) != NGX_OK) {
                 return NGX_ERROR;
             }
+
+        } else {
+            ngx_quic_unref_client_id(c, cid);
         }
-
-        ngx_quic_unref_client_id(c, cid);
     }
 
 done:
@@ -534,7 +535,9 @@ ngx_quic_unref_client_id(ngx_connection_
 {
     ngx_quic_connection_t  *qc;
 
-    cid->refcnt--;
+    if (cid->refcnt) {
+        cid->refcnt--;
+    } /* else: unused client id */
 
     if (cid->refcnt) {
         return;