From 1b81c08de8fd10035d5ae060b81747c6b880c906 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Wed, 24 Mar 2021 18:58:40 -0700
Subject: [PATCH] GB Video: Don't rendering negative batches

---
 CHANGES                     | 1 +
 src/gb/renderers/software.c | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/CHANGES b/CHANGES
index cafec635b..330f9d992 100644
--- a/CHANGES
+++ b/CHANGES
@@ -89,6 +89,7 @@ Other fixes:
  - GB Video: Fix SGB video logs
  - GB Video: Discard SGB packets in non-SGB mVLs
  - GB Video: Fix deserializing negative LX state
+ - GB Video: Don't rendering negative batches
  - GBA: Fix loading multiboot ELF files (fixes mgba.io/i/1949)
  - GBA: Fix loading subsequent save files (fixes mgba.io/i/2067)
  - mGUI: Don't attempt to preload files larger than can fit in RAM
diff --git a/src/gb/renderers/software.c b/src/gb/renderers/software.c
index 542aec901..f023d99b4 100644
--- a/src/gb/renderers/software.c
+++ b/src/gb/renderers/software.c
@@ -565,6 +565,9 @@ static void GBVideoSoftwareRendererDrawRange(struct GBVideoRenderer* renderer, i
 	struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
 	softwareRenderer->lastY = y;
 	softwareRenderer->lastX = endX;
+	if (startX >= endX) {
+		return;
+	}
 	uint8_t* maps = &softwareRenderer->d.vram[GB_BASE_MAP];
 	if (GBRegisterLCDCIsTileMap(softwareRenderer->lcdc)) {
 		maps += GB_SIZE_MAP;