From 5fd0ba0d6725d6e0f9da2a3ff86b4c28fb085bc1 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Sun, 23 Feb 2025 22:49:08 -0800
Subject: [PATCH] GBA Cheats: Let VBA-style codes patch ROM (fixes #3423)

---
 CHANGES          |  1 +
 src/gba/cheats.c | 27 +++++++++++++++++++--------
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/CHANGES b/CHANGES
index 6b2bff781..f998666bc 100644
--- a/CHANGES
+++ b/CHANGES
@@ -30,6 +30,7 @@ Other fixes:
  - FFmpeg: Fix failing to record videos with CRF video (fixes mgba.io/i/3368)
  - GB Core: Fix cloning savedata when backing file is outdated (fixes mgba.io/i/3388)
  - GBA: Fix getting game info for multiboot ROMs
+ - GBA Cheats: Let VBA-style codes patch ROM (fixes mgba.io/i/3423)
  - GBA Core: Fix booting into BIOS when skip BIOS is enabled
  - GBA Hardware: Fix loading states unconditionally overwriting GPIO memory
  - mGUI: Load parent directory if last used directory is missing (fixes mgba.io/i/3379)
diff --git a/src/gba/cheats.c b/src/gba/cheats.c
index d055194be..4fb23b1de 100644
--- a/src/gba/cheats.c
+++ b/src/gba/cheats.c
@@ -180,14 +180,25 @@ bool GBACheatAddVBALine(struct GBACheatSet* cheats, const char* line) {
 		return false;
 	}
 
-	struct mCheat* cheat = mCheatListAppend(&cheats->d.list);
-	cheat->address = address;
-	cheat->operandOffset = 0;
-	cheat->addressOffset = 0;
-	cheat->repeat = 1;
-	cheat->type = CHEAT_ASSIGN;
-	cheat->width = width;
-	cheat->operand = value;
+	if (address < GBA_BASE_ROM0 || address >= GBA_BASE_SRAM) {
+		struct mCheat* cheat = mCheatListAppend(&cheats->d.list);
+		memset(cheat, 0, sizeof(*cheat));
+		cheat->address = address;
+		cheat->operandOffset = 0;
+		cheat->addressOffset = 0;
+		cheat->repeat = 1;
+		cheat->type = CHEAT_ASSIGN;
+		cheat->width = width;
+		cheat->operand = value;
+	} else {
+		struct mCheatPatch* patch = mCheatPatchListAppend(&cheats->d.romPatches);
+		memset(patch, 0, sizeof(*patch));
+		patch->width = width;
+		patch->address = address;
+		patch->segment = 0;
+		patch->value = value;
+		patch->check = false;
+	}
 	return true;
 }