swaylock: Fix crash when unable to connect to wl

Prevent swaylock from crashing when it can't connect to wayland for
whatever reason. i.e. XDG_RUNTIME_DIR not set.

Fix #534

1 files changed, 7 insertions, 1 deletions

diff --git a/swaylock/main.c b/swaylock/main.c
index f2015a05..3f0fc867 100644
--- a/swaylock/main.c
+++ b/swaylock/main.c
@@ -31,7 +31,9 @@ void sway_terminate(int exit_code) {
                 window_teardown(window);
         }
         list_free(surfaces);
-        registry_teardown(registry);
+        if (registry) {
+                registry_teardown(registry);
+        }
         exit(exit_code);
 }
 
@@ -292,6 +294,10 @@ int main(int argc, char **argv) {
         surfaces = create_list();
         registry = registry_poll();
 
+        if (!registry) {
+                sway_abort("Unable to connect to wayland compositor");
+        }
+
         if (!registry->swaylock) {
                 sway_abort("swaylock requires the compositor to support the swaylock extension.");
         }