Follow up to 70aa7e0 to fix a potential crash.

src/map/status.c

@@ -2027,8 +2027,8 @@ int status_check_visibility(struct block_list *src, struct block_list *target)
 			}
 			break;
 		default:
-				if (((tsc->option&(OPTION_HIDE|OPTION_CLOAK|OPTION_CHASEWALK)) || tsc->data[SC_CAMOUFLAGE] || tsc->data[SC_STEALTHFIELD]) && !(status->mode&(MD_BOSS|MD_DETECTOR)))
-					return 0;
+			if (tsc && ((tsc->option&(OPTION_HIDE|OPTION_CLOAK|OPTION_CHASEWALK)) || tsc->data[SC_CAMOUFLAGE] || tsc->data[SC_STEALTHFIELD]) && !(status->mode&(MD_BOSS|MD_DETECTOR)))
+				return 0;
 	}
 
 	return 1;