virtual: Fix memory leak when selecting mailboxes with '-' or /metadata

src/plugins/virtual/virtual-config.c

@@ -392,7 +392,7 @@ static int virtual_config_expand_wildcards(struct virtual_parse_context *ctx,
 	struct mail_user *user = ctx->mbox->storage->storage.user;
 	ARRAY_TYPE(virtual_backend_box) wildcard_boxes, neg_boxes, metadata_boxes;
 	struct mailbox_list_iterate_context *iter;
-	struct virtual_backend_box *const *wboxes;
+	struct virtual_backend_box *const *wboxes, *const *boxp;
 	const char **patterns;
 	const struct mailbox_info *info;
 	unsigned int i, j, count;
@@ -440,6 +440,10 @@ static int virtual_config_expand_wildcards(struct virtual_parse_context *ctx,
 	}
 	for (i = 0; i < count; i++)
 		mail_search_args_unref(&wboxes[i]->search_args);
+	array_foreach(&neg_boxes, boxp)
+		mail_search_args_unref(&(*boxp)->search_args);
+	array_foreach(&metadata_boxes, boxp)
+		mail_search_args_unref(&(*boxp)->search_args);
 	if (mailbox_list_iter_deinit(&iter) < 0) {
 		*error_r = mailbox_list_get_last_internal_error(user->namespaces->list, NULL);
 		return -1;