From 54cd85d236f149c66994dd1bc6334ac63effc058 Mon Sep 17 00:00:00 2001
From: Jeffrey Pfau <jeffrey@endrift.com>
Date: Mon, 12 Sep 2016 20:15:40 -0700
Subject: [PATCH] GB Video: Prevent dot clock from going negative

---
 src/gb/video.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/gb/video.c b/src/gb/video.c
index e83205cdc..92f19cef5 100644
--- a/src/gb/video.c
+++ b/src/gb/video.c
@@ -257,6 +257,9 @@ void GBVideoProcessDots(struct GBVideo* video) {
 	video->x = video->dotCounter + video->eventDiff + (video->p->cpu->cycles >> video->p->doubleSpeed);
 	if (video->x > GB_VIDEO_HORIZONTAL_PIXELS) {
 		video->x = GB_VIDEO_HORIZONTAL_PIXELS;
+	} else if (video->x < 0) {
+		mLOG(GB, FATAL, "Video dot clock went negative!");
+		video->x = oldX;
 	}
 	if (video->x == GB_VIDEO_HORIZONTAL_PIXELS) {
 		video->dotCounter = INT_MIN;