From f04928432487bfdea7085e21861f624e531143d3 Mon Sep 17 00:00:00 2001
From: Lior Halphon <LIJI32@gmail.com>
Date: Tue, 20 Sep 2016 01:22:21 +0300
Subject: [PATCH] Emulate the HALT bug on a DMG

---
 Core/z80_cpu.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Core/z80_cpu.c b/Core/z80_cpu.c
index 2ea16d3..6db9007 100644
--- a/Core/z80_cpu.c
+++ b/Core/z80_cpu.c
@@ -1333,7 +1333,10 @@ void GB_cpu_run(GB_gameboy_t *gb)
 {
     gb->vblank_just_occured = false;
     bool interrupt = gb->interrupt_enable & gb->io_registers[GB_IO_IF];
+    bool halt_bug = false;
+
     if (interrupt) {
+        halt_bug = gb->halted && !gb->is_cgb; /* Todo: Does this bug happen on a CGB? */
         gb->halted = false;
     }
 
@@ -1363,6 +1366,9 @@ void GB_cpu_run(GB_gameboy_t *gb)
     }
     else if(!gb->halted && !gb->stopped) {
         uint8_t opcode = GB_read_memory(gb, gb->pc++);
+        if (halt_bug) {
+            gb->pc--;
+        }
         opcodes[opcode](gb, opcode);
     }
     else {