From 04788e15af6878c220602d2248b2b8f5182e96a0 Mon Sep 17 00:00:00 2001
From: Rangi <remy.oukaour+rangi42@gmail.com>
Date: Sat, 1 May 2021 22:33:54 -0400
Subject: [PATCH] Fix a potential out-of-bounds array access in RGBGFX

This was caught by ASAN for pokered's gfx/battle/minimize.png.
---
 src/gfx/gb.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/gfx/gb.c b/src/gfx/gb.c
index 22ab2b2f..2391a656 100644
--- a/src/gfx/gb.c
+++ b/src/gfx/gb.c
@@ -224,7 +224,11 @@ void create_mapfiles(const struct Options *opts, struct GBImage *gb,
 		if (!tile)
 			err(1, "%s: Failed to allocate memory for tile",
 			    __func__);
-		for (i = 0; i < tile_size; i++) {
+		/*
+		 * If the input image doesn't fill the last tile,
+		 * `gb_i` will reach `gb_size`.
+		 */
+		for (i = 0; i < tile_size && gb_i < gb_size; i++) {
 			tile[i] = gb->data[gb_i];
 			gb_i++;
 		}