From 4dd6a2930a863dac9a5c7c09ef6f9aaaca5c5ab0 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Mon, 2 Sep 2019 22:06:10 -0700
Subject: [PATCH] GB: Fix SGB controller incrementing (fixes #1104)

---
 CHANGES     | 1 +
 src/gb/io.c | 9 +++------
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/CHANGES b/CHANGES
index acffec166..5dc7c52c4 100644
--- a/CHANGES
+++ b/CHANGES
@@ -21,6 +21,7 @@ Other fixes:
  - GBA: Set up GPIO mapping on null and ELF ROM regions (fixes mgba.io/i/1481)
  - GBA Cheats: Fix value incrementing in CB slide codes (fixes mgba.io/i/1501)
  - Qt: Improve cheat view UX
+ - GB: Fix SGB controller incrementing (fixes mgba.io/i/1104)
 Misc:
  - Qt: Make mute menu option also toggle fast-forward mute (fixes mgba.io/i/1424)
  - Qt: Show error message if file failed to load
diff --git a/src/gb/io.c b/src/gb/io.c
index d044ad05d..86cbe8865 100644
--- a/src/gb/io.c
+++ b/src/gb/io.c
@@ -119,14 +119,11 @@ static void _writeSGBBits(struct GB* gb, int bits) {
 	if (gb->sgbBit > 128) {
 		switch (bits) {
 		case 1:
-			gb->sgbBit |= 2;
-			break;
-		case 2:
-			gb->sgbBit |= 4;
+			gb->sgbBit ^= 2;
 			break;
 		case 3:
-			if (gb->sgbBit == 135) {
-				gb->sgbBit &= ~6;
+			if (gb->sgbBit == 131) {
+				gb->sgbBit &= ~2;
 				gb->sgbCurrentController = (gb->sgbCurrentController + 1) & gb->sgbControllers;
 			}
 			break;