commit 8f052596b2c79e74c0e47b93595f13a754b3e2ef
from: Anselm R Garbe <garbeam@gmail.com>
date: Wed Jun 11 18:42:24 2008 UTC

crash fix

commit - 9463d5354bc57d0c0086b7328196d7af60ed706d
commit + 8f052596b2c79e74c0e47b93595f13a754b3e2ef
blob - ec37588b1316baa359101196890fcbdeec2e7644
blob + f5aa010aaec2d0b3d7e9563f934ed2f08b909faf
--- dwm.c
+++ dwm.c
@@ -1478,7 +1478,7 @@ togglefloating(const Arg *arg) {
 
 void
 togglelayout(const Arg *arg) {
-	if(arg->v)
+	if(arg && arg->v)
 		lt = (Layout *)arg->v;
 	else if(++lt == &layouts[LENGTH(layouts)])
 		lt = &layouts[0];