fix crash: urgent floating con on separate workspace (thanks Piotr)

If there is a single floating con on a separate workspace that is not
focused, and this con becomes urgent, switching back to that workspace
may result in a crash of i3. This is because while setting the urgency
of parent containers, 'parent' may become NULL in case of floating
containers. This commit checks the validity of parent.

fixes #821

diff --git a/src/con.c b/src/con.c
index db9ad5ee56861e16b3000a9dfe3f626bb65ef5ab..0539c7ab6be526dfbbad725e38009dc9497b5060 100644 (file)
--- a/src/con.c
+++ b/src/con.c
@@ -1424,7 +1424,7 @@ void con_update_parents_urgency(Con *con) {
     Con *parent = con->parent;
 
     bool new_urgency_value = con->urgent;
-    while (parent->type != CT_WORKSPACE && parent->type != CT_DOCKAREA) {
+    while (parent && parent->type != CT_WORKSPACE && parent->type != CT_DOCKAREA) {
         if (new_urgency_value) {
             parent->urgent = true;
         } else {