From 9e8c152ddeb48df8e1aaabb994370cc51e82f964 Mon Sep 17 00:00:00 2001
From: feos <feos-theos@yandex.ru>
Date: Mon, 29 Aug 2016 21:18:55 +0300
Subject: [PATCH] tastudio history: fix bug where undoing the movie extension
 (caused by drawing beyond the movie length) would swallow all the movie

---
 BizHawk.Client.Common/movie/tasproj/TasMovie.History.cs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/BizHawk.Client.Common/movie/tasproj/TasMovie.History.cs b/BizHawk.Client.Common/movie/tasproj/TasMovie.History.cs
index d59a8b82e5..1b00ba1d3c 100644
--- a/BizHawk.Client.Common/movie/tasproj/TasMovie.History.cs
+++ b/BizHawk.Client.Common/movie/tasproj/TasMovie.History.cs
@@ -335,6 +335,8 @@ namespace BizHawk.Client.Common
 			var minuend = Math.Min(lastFrame + 1, movie.InputLogLength);
 			if (firstFrame > minuend)
 				undoLength = minuend;
+			else if (firstFrame == minuend)
+				undoLength = Math.Max(lastFrame + 1, movie.InputLogLength) - firstFrame;
 			else
 				undoLength = minuend - firstFrame;