From 68ef5d3a5b32def3a07650d6bf6412ef6d5068ca Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Thu, 30 Jun 2022 04:20:30 -0700
Subject: [PATCH] GB: Fix replacing the ROM crashing when accessing ROM base

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

diff --git a/CHANGES b/CHANGES
index 382ce85ad..3855918da 100644
--- a/CHANGES
+++ b/CHANGES
@@ -57,6 +57,7 @@ Other fixes:
  - FFmpeg: Fix crash when encoding audio with some containers
  - FFmpeg: Fix GIF recording (fixes mgba.io/i/2393)
  - GB: Fix temporary saves
+ - GB: Fix replacing the ROM crashing when accessing ROM base
  - GB, GBA: Save writeback-pending masked saves on unload (fixes mgba.io/i/2396)
  - mGUI: Fix FPS counter after closing menu
  - Qt: Fix some hangs when using the debugger console
diff --git a/src/gb/gb.c b/src/gb/gb.c
index edcd548d1..81d059b00 100644
--- a/src/gb/gb.c
+++ b/src/gb/gb.c
@@ -189,6 +189,9 @@ bool GBLoadROM(struct GB* gb, struct VFile* vf) {
 
 	if (gb->cpu) {
 		struct SM83Core* cpu = gb->cpu;
+		if (!gb->memory.romBase) {
+			GBMBCSwitchBank0(gb, 0);
+		}
 		cpu->memory.setActiveRegion(cpu, cpu->pc);
 	}