From c2de079a9d08982c2d8a66b7f6105b8ae3e05094 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Mon, 22 Mar 2021 23:48:19 -0700
Subject: [PATCH] GB: Properly unmap ROM base when unloading ROM

---
 src/gb/gb.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/gb/gb.c b/src/gb/gb.c
index 79d309cf6..404c660c3 100644
--- a/src/gb/gb.c
+++ b/src/gb/gb.c
@@ -293,6 +293,10 @@ void GBSavedataUnmask(struct GB* gb) {
 
 void GBUnloadROM(struct GB* gb) {
 	// TODO: Share with GBAUnloadROM
+	off_t romBase = gb->memory.romBase - gb->memory.rom;
+	if (romBase >= 0 && ((size_t) romBase < gb->memory.romSize || (size_t) romBase < gb->yankedRomSize)) {
+		gb->memory.romBase = NULL;
+	}
 	if (gb->memory.rom && !gb->isPristine) {
 		if (gb->yankedRomSize) {
 			gb->yankedRomSize = 0;