Suppress stale connection UP after its callback removes the last path

src/transport_layer/etcp.c

@@ -320,7 +320,12 @@ static void etcp_on_up(struct ETCP_CONN* etcp) {
     strbuf_free(&sb);
     (void)elapsed_ms;
     etcp_cbk_fire(etcp, ETCP_CBK_EVENT_UP);
-    if (!etcp->close_requested) etcp_fire_conn_status(etcp, ETCP_CONN_STATUS_UP);
+    if (etcp->close_requested || !etcp->links_up) {
+        DEBUG_DEBUG(DEBUG_CATEGORY_ETCP, "[%s] UP publication stopped after callback: closing=%u links_up=%u",
+            etcp->log_name, etcp->close_requested, etcp->links_up);
+        return;
+    }
+    etcp_fire_conn_status(etcp, ETCP_CONN_STATUS_UP);
 }
 
 static void etcp_on_down(struct ETCP_CONN* etcp, struct ETCP_LINK* down_link) {