lib-storage: If mailbox_create() fails, don't leave box in partially …

…opened state.

For example with sdbox it may have opened the indexes, but not set mailbox's
GUID. A following MAILBOX_METADATA_GUID would then assert-crash because GUID
is empty.

src/lib-storage/mail-storage.c

@@ -1330,6 +1330,13 @@ int mailbox_create(struct mailbox *box, const struct mailbox_update *update,
 	box->creating = FALSE;
 	if (ret == 0)
 		box->list->guid_cache_updated = TRUE;
+	else if (box->opened) {
+		/* Creation failed after (partially) opening the mailbox.
+		   It may not be in a valid state, so close it. */
+		mail_storage_last_error_push(box->storage);
+		mailbox_close(box);
+		mail_storage_last_error_pop(box->storage);
+	}
 	return ret;
 }