From 6df55275b864fefa31122004e74d35ddde6885b6 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Wed, 1 Feb 2017 13:47:03 -0800
Subject: [PATCH] GB: Fix crash when patching ROM

---
 CHANGES     | 1 +
 src/gb/gb.c | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/CHANGES b/CHANGES
index 5c4f6c5db..00a4b642e 100644
--- a/CHANGES
+++ b/CHANGES
@@ -8,6 +8,7 @@ Bugfixes:
  - Qt: Fix timing issues on high refresh rate monitors
  - GBA Savedata: Fix savedata unmasking (fixes mgba.io/i/441)
  - Util: Fix overflow when loading invalid UPS patches
+ - GB: Fix crash when patching ROMs
 Misc:
  - Qt: Improved HiDPI support
  - Feature: Support ImageMagick 7
diff --git a/src/gb/gb.c b/src/gb/gb.c
index d9c61f9f6..91234a2af 100644
--- a/src/gb/gb.c
+++ b/src/gb/gb.c
@@ -285,12 +285,16 @@ void GBApplyPatch(struct GB* gb, struct Patch* patch) {
 	if (patchedSize > GB_SIZE_CART_MAX) {
 		patchedSize = GB_SIZE_CART_MAX;
 	}
+	void* oldRom = gb->memory.rom;
 	gb->memory.rom = anonymousMemoryMap(GB_SIZE_CART_MAX);
 	if (!patch->applyPatch(patch, gb->pristineRom, gb->pristineRomSize, gb->memory.rom, patchedSize)) {
 		mappedMemoryFree(gb->memory.rom, patchedSize);
 		gb->memory.rom = gb->pristineRom;
 		return;
 	}
+	if (gb->memory.romBase == oldRom) {
+		gb->memory.romBase = gb->memory.rom;
+	}
 	gb->memory.romSize = patchedSize;
 	gb->romCrc32 = doCrc32(gb->memory.rom, gb->memory.romSize);
 }