focus: Fix moving last workspace.

If there's only one workspace on an output and it's moved to a different
output then active workspace will be NULL.

1 files changed, 4 insertions, 1 deletions

diff --git a/sway/focus.c b/sway/focus.c
index c60f410c..c1170ca4 100644
--- a/sway/focus.c
+++ b/sway/focus.c
@@ -96,7 +96,10 @@ bool set_focused_container(swayc_t *c) {
                 return false;
         }
         swayc_t *active_ws = swayc_active_workspace();
-        int active_ws_child_count = active_ws->children->length + active_ws->floating->length;
+        int active_ws_child_count = 0;
+        if (active_ws) {
+                active_ws_child_count = active_ws->children->length + active_ws->floating->length;
+        }
 
         swayc_log(L_DEBUG, c, "Setting focus to %p:%ld", c, c->handle);