Fix crashes when running certain commands on an empty workspace

This fixes crashes when running the border, mark, unmark and
title_format commands on an empty workspace.

1 files changed, 1 insertions, 1 deletions

diff --git a/sway/commands/unmark.c b/sway/commands/unmark.c
index c6251dc8..c671ed4e 100644
--- a/sway/commands/unmark.c
+++ b/sway/commands/unmark.c
@@ -25,7 +25,7 @@ struct cmd_results *cmd_unmark(int argc, char **argv) {
         struct sway_view *view = NULL;
         if (config->handler_context.using_criteria) {
                 struct sway_container *container = config->handler_context.container;
-                if (!container->view) {
+                if (!container || !container->view) {
                         return cmd_results_new(CMD_INVALID, "unmark",
                                         "Only views can have marks");
                 }