From e787fcee8edac745c3509bd702c5ed8e62dd1608 Mon Sep 17 00:00:00 2001
From: Abdessamad Derraz <3028866+Abdess@users.noreply.github.com>
Date: Tue, 6 Oct 2026 12:15:50 +0200
Subject: [PATCH] fix: leave bizhawk's declared sha1 to bizhawk

---
 scripts/exporter/bizhawk_exporter.py |  7 +++++--
 tests/test_export_counts.py          | 14 ++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/scripts/exporter/bizhawk_exporter.py b/scripts/exporter/bizhawk_exporter.py
index 2d56dfd4..f1f9c756 100644
--- a/scripts/exporter/bizhawk_exporter.py
+++ b/scripts/exporter/bizhawk_exporter.py
@@ -11,7 +11,7 @@ from __future__ import annotations
 import re
 
 from .base_exporter import BaseExporter
-from .baseline import NativeFile, NativeSystem, Report
+from .baseline import NativeFile, NativeSystem, Report, _hash_values
 
 SOURCE_URL = (
     "https://raw.githubusercontent.com/TASEmulators/BizHawk/master"
@@ -80,7 +80,10 @@ class Exporter(BaseExporter):
         seen: dict[str, list[NativeFile]] = {}
         for system in systems.values():
             for fe in system.files:
-                if fe.hash("sha1"):
+                # A SHA1 BizHawk declares is BizHawk's own code, the authority
+                # for its cores: the truth's MSX.rom came from FBNeo and would
+                # have made MSXHawk refuse the dump it accepts.
+                if fe.hash("sha1") and not _hash_values(fe.platform or {}, "sha1"):
                     seen.setdefault(fe.name.casefold(), []).append(fe)
         resolved: dict[str, NativeFile] = {}
         for name, entries in seen.items():
diff --git a/tests/test_export_counts.py b/tests/test_export_counts.py
index 2b1acd24..07a2ea93 100644
--- a/tests/test_export_counts.py
+++ b/tests/test_export_counts.py
@@ -205,6 +205,20 @@ class OneMd5FormatsAddWhole(unittest.TestCase):
         self.assertTrue(Batocera.writable(single))
 
 
+class BizHawkKeepsItsOwnHashes(unittest.TestCase):
+    def test_a_declared_sha1_is_not_replaced(self):
+        """FBNeo's MSX.rom replaced the SHA1 MSXHawk accepts in BizHawk's code."""
+        sha_bizhawk, sha_fbneo = "4" * 40, "e" * 40
+        fe = NativeFile("MSX.rom", "MSX.rom", "MSX", platform={"sha1": sha_bizhawk},
+                        truth={"sha1": sha_fbneo}, corrections=["sha1"])
+        exporter = BizHawk()
+        source = f'FirmwareAndOption("{sha_bizhawk.upper()}", 32768, "MSX", "b", "MSX.rom", "d");\n'
+        produced = exporter.render({"MSX": NativeSystem("MSX", files=[fe])}, None,
+                                   {exporter.native_filename(): source})
+        self.assertIn(sha_bizhawk.upper(), produced[exporter.native_filename()])
+        self.assertFalse(exporter.states(fe, "sha1"))
+
+
 class ModelKeepsOneFileOneEntry(unittest.TestCase):
     def test_a_list_of_sizes_is_not_one_size(self):
         """A profile may accept several revisions; int() on the list crashed."""