From 97eb3fe209ac2539b8a8ea2547018615801c01d9 Mon Sep 17 00:00:00 2001
From: Lior Halphon <LIJI32@gmail.com>
Date: Tue, 20 Sep 2016 22:59:00 +0300
Subject: [PATCH 1/2] Detect games stuck on blank screens

---
 Tester/main.c | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/Tester/main.c b/Tester/main.c
index 52d797c..94450a4 100755
--- a/Tester/main.c
+++ b/Tester/main.c
@@ -89,15 +89,29 @@ static void vblank(GB_gameboy_t *gb)
         }
     }
 
-    if (frames == test_length) {
-        FILE *f = fopen(bmp_filename, "wb");
-        fwrite(&bmp_header, 1, sizeof(bmp_header), f);
-        fwrite(&bitmap, 1, sizeof(bitmap), f);
-        fclose(f);
-        if (!gb->boot_rom_finished) {
-            GB_log(gb, "Boot ROM did not finish.\n");
+    if (frames >= test_length ) {
+        bool is_screen_blank = false;
+        if (!(gb->io_registers[GB_IO_LCDC] & 0x80)) { /* LCD is off */
+            is_screen_blank = true;
+        }
+        else if(!gb->cgb_mode) { /* BG can't be disabled in CGB mode */
+            is_screen_blank =!(gb->io_registers[GB_IO_LCDC] & (gb->is_cgb? 3 : 0x23));
+        }
+        
+        /* Let the test run for an extra 8 frames if the screen is off/disabled */
+        if (!is_screen_blank || frames >= test_length + 8) {
+            FILE *f = fopen(bmp_filename, "wb");
+            fwrite(&bmp_header, 1, sizeof(bmp_header), f);
+            fwrite(&bitmap, 1, sizeof(bitmap), f);
+            fclose(f);
+            if (!gb->boot_rom_finished) {
+                GB_log(gb, "Boot ROM did not finish.\n");
+            }
+            if (is_screen_blank) {
+                GB_log(gb, "Game probably stuck with blank screen. \n");
+            }
+            running = false;
         }
-        running = false;
     }
     else if (frames == test_length - 1) {
         gb->disable_rendering = false;

From 6f2b36cacb90a9cc0ec4acb1fa8c8c4c3257b9e7 Mon Sep 17 00:00:00 2001
From: Lior Halphon <LIJI32@gmail.com>
Date: Tue, 20 Sep 2016 22:59:25 +0300
Subject: [PATCH 2/2] The HALT bug also happens on CGBs, regardless of DMG
 mode.

---
 Core/z80_cpu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Core/z80_cpu.c b/Core/z80_cpu.c
index 6db9007..b664ace 100644
--- a/Core/z80_cpu.c
+++ b/Core/z80_cpu.c
@@ -1336,7 +1336,8 @@ void GB_cpu_run(GB_gameboy_t *gb)
     bool halt_bug = false;
 
     if (interrupt) {
-        halt_bug = gb->halted && !gb->is_cgb; /* Todo: Does this bug happen on a CGB? */
+        /* Despite what some online documentations say, the HALT bug also happens on a CGB, in both CGB and DMG modes. */
+        halt_bug = gb->halted;
         gb->halted = false;
     }