Fixed another stack of runtime errors.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@225 316c924e-a436-60f5-8080-3fe189b3f50e

code/game/objects/alien/facehugger.dm

@@ -324,7 +324,8 @@
 							for(var/atom/A in get_turf(weed))
 								if(A.density) continue find_weeds
 							the_weeds += weed
-					W = pick(the_weeds)
+					if(the_weeds.len)
+						W = pick(the_weeds)
 
 				if(W)
 					path_idle(W)

code/game/objects/weapons.dm

@@ -94,7 +94,8 @@
 	..()
 
 /obj/item/assembly/time_ignite/attack_self(mob/user as mob)
-	src.part1.attack_self(user, src.status)
+	if (src.part1)
+		src.part1.attack_self(user, src.status)
 	src.add_fingerprint(user)
 	return