From a8a7d459561c1416278ca87ce999b31ea2576c5c Mon Sep 17 00:00:00 2001
From: Richard Davey <rich@photonstorm.com>
Date: Wed, 3 Jul 2019 15:07:53 +0100
Subject: [PATCH] Removing a frame from a 2 frame animation would cause an
 error when a Sprite using that animation next tried to render. Fix #4621

---
 CHANGELOG.md                |  1 +
 src/animations/Animation.js | 22 +++++++++++++++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index db192182d..a9f905304 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -80,6 +80,7 @@
 * `Tilemap.createFromObjects` would ignore the `scene` argument passed in to the method. It's now used (thanks @samme)
 * Fixed a bug in the WebGL and Canvas Renderers where a Sprite with a `flipX` or `flipY` value set would render the offset frames slightly out of place, causing the animation to appear jittery. Also, the sprite would be out of place by its origin. Fix #4636 #3813  (thanks @jronn @B3L7)
 * Animations with custom pivots, like those created in Texture Packer with the pivot option enabled, would be mis-aligned if flipped. They now render in the correct position, regardless of scale or flip on either axis. Fix #4155 (thanks @Zax37)
+* Removing a frame from a 2 frame animation would cause an error when a Sprite using that animation next tried to render. Fix #4621 (thanks @orlicgms)
 
 ### Examples, Documentation and TypeScript
 
diff --git a/src/animations/Animation.js b/src/animations/Animation.js
index 6d892db9a..d2c0fb883 100644
--- a/src/animations/Animation.js
+++ b/src/animations/Animation.js
@@ -843,9 +843,11 @@ var Animation = new Class({
         var len = this.frames.length;
         var slice = 1 / (len - 1);
 
+        var frame;
+
         for (var i = 0; i < len; i++)
         {
-            var frame = this.frames[i];
+            frame = this.frames[i];
 
             frame.index = i + 1;
             frame.isFirst = false;
@@ -855,11 +857,21 @@ var Animation = new Class({
             if (i === 0)
             {
                 frame.isFirst = true;
-                frame.isLast = (len === 1);
-                frame.prevFrame = this.frames[len - 1];
-                frame.nextFrame = this.frames[i + 1];
+
+                if (len === 1)
+                {
+                    frame.isLast = true;
+                    frame.nextFrame = frame;
+                    frame.prevFrame = frame;
+                }
+                else
+                {
+                    frame.isLast = false;
+                    frame.prevFrame = this.frames[len - 1];
+                    frame.nextFrame = this.frames[i + 1];
+                }
             }
-            else if (i === len - 1)
+            else if (i === len - 1 && len > 1)
             {
                 frame.isLast = true;
                 frame.prevFrame = this.frames[len - 2];