From f16d16099411c39493b4e3266358fce70bebe529 Mon Sep 17 00:00:00 2001
From: Nolan Darilek <nolan@thewordnerd.info>
Date: Thu, 17 Mar 2022 12:39:35 -0500
Subject: [PATCH] Avoid possible crash.

---
 src/visibility.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/visibility.rs b/src/visibility.rs
index 3275229..de97870 100644
--- a/src/visibility.rs
+++ b/src/visibility.rs
@@ -15,6 +15,7 @@ use shadowcast::{vision_distance, Context, InputGrid};
 
 use crate::{
     bevy_rapier2d::prelude::*,
+    commands::RunIfExistsExt,
     core::{Angle, Coordinates, Player, PointLike},
     log::Log,
     map::{ITileType, Map, MapConfig},
@@ -294,9 +295,10 @@ fn update_viewshed<D: 'static + Clone + Default + Send + Sync>(
             position.position.translation.x,
             position.position.translation.y,
         );
-        commands
-            .entity(entity)
-            .insert(LastCoordinates(coordinates.i32()));
+        let coordinates_i32 = coordinates.i32();
+        commands.run_if_exists(entity, move |mut entity| {
+            entity.insert(LastCoordinates(coordinates_i32));
+        });
         if viewers.get_mut(entity).is_ok() {
             if let Some(last_coordinates) = last_coordinates {
                 if **last_coordinates != coordinates.i32() {