Publish staged results only when the database commit succeeds

src/chat/merkle_sync.c

@@ -149,7 +149,7 @@ static void ms_abort_pull(struct ms_session* s) {
 /* Commit не вызывает внешний код; публикация откладывается до безопасного выхода из receive. */
 static int ms_commit_pull(struct ms_session* s) {
     int rc = s->dataset->ops->commit_pull(s->dataset->data_ctx, s->pull);
-    if (s->dataset->ops->publish_pull) { s->finished_pull = s->pull; s->pull = NULL; }
+    if (rc >= 0 && s->dataset->ops->publish_pull) { s->finished_pull = s->pull; s->pull = NULL; }
     else ms_abort_pull(s);
     return rc;
 }