From 592f8fef2dcbce6f76af1569e13e483d9a0a9772 Mon Sep 17 00:00:00 2001
From: Abdessamad Derraz <3028866+Abdess@users.noreply.github.com>
Date: Sun, 18 Oct 2026 07:40:32 +0200
Subject: [PATCH] fix: exit 2 when the BIOS folder cannot be made

---
 install.ps1           |  2 +-
 install.py            |  6 +++++-
 install.sh            |  2 +-
 tests/test_install.py | 40 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/install.ps1 b/install.ps1
index 98f34278..57e5a66f 100644
--- a/install.ps1
+++ b/install.ps1
@@ -8,7 +8,7 @@ param(
 
 $ErrorActionPreference = "Stop"
 $defaultInstallUrl = "https://raw.githubusercontent.com/Abdess/retrobios/main/install.py"
-$defaultInstallSha256 = "974ecc9fd5fc23433ebd50488629abc20aa861a21389cf31044643ddd6e62418"
+$defaultInstallSha256 = "8c5f113a893373b7bc0be00766f52b5c1629b9d6a587291428c06fed5c5ea61f"
 $maximumInstallerBytes = 2MB
 $installerExit = 0
 $installer = if ($PSScriptRoot) { Join-Path $PSScriptRoot "install.py" } else { $null }
diff --git a/install.py b/install.py
index 5b424eba..0da6a110 100644
--- a/install.py
+++ b/install.py
@@ -3273,11 +3273,15 @@ def _install(args: argparse.Namespace, real_stdout: TextIO) -> None:
             try:
                 bios_path.mkdir(parents=True, exist_ok=True)
             except OSError as exc:
+                sys.stdout.flush()
                 print(f"\nCannot create {bios_path}.", file=sys.stderr)
                 print(f"  {exc.strerror}.", file=sys.stderr)
                 print(_write_advice(bios_path, bios_path in assumed_dests),
                       file=sys.stderr)
-                sys.exit(1)
+                # The documented code for a folder that cannot be written,
+                # as when it exists read-only; 1 once an earlier platform
+                # of the run installed something.
+                sys.exit(1 if total_downloaded else 2)
             _check_free_space(bios_path, dl_size)
             progress = Progress(len(to_download), dl_size, term)
             failed, interrupted = download_files(
diff --git a/install.sh b/install.sh
index fe8db511..319b4ef0 100755
--- a/install.sh
+++ b/install.sh
@@ -18,7 +18,7 @@ esac
 TEMP_INSTALLER=""
 TEMP_DIRECTORY=""
 DEFAULT_INSTALL_URL="https://raw.githubusercontent.com/Abdess/retrobios/main/install.py"
-DEFAULT_INSTALL_SHA256="974ecc9fd5fc23433ebd50488629abc20aa861a21389cf31044643ddd6e62418"
+DEFAULT_INSTALL_SHA256="8c5f113a893373b7bc0be00766f52b5c1629b9d6a587291428c06fed5c5ea61f"
 MAX_INSTALLER_BYTES=2097152
 
 cleanup() {
diff --git a/tests/test_install.py b/tests/test_install.py
index e87ef7d8..88747002 100644
--- a/tests/test_install.py
+++ b/tests/test_install.py
@@ -13,6 +13,7 @@ import shlex
 import re
 import shutil
 import subprocess
+import sys
 import tempfile
 import threading
 import unittest
@@ -2064,5 +2065,44 @@ class ThePowerShellWrapperPassesTheStatusOn(unittest.TestCase):
                 self.assertEqual(proc.returncode, code, proc.stderr)
                 self.assertNotIn("installer failed", proc.stdout + proc.stderr)
 
+
+@unittest.skipIf(os.name == "nt" or os.geteuid() == 0, "needs a folder this user cannot write")
+class AnUnwritableFolderIsCodeTwo(unittest.TestCase):
+    """A BIOS folder that could not be created ended with 1, while the same
+    folder existing read-only ended with the documented 2."""
+
+    def test_both_shapes_exit_two(self):
+        handler = functools.partial(
+            http.server.SimpleHTTPRequestHandler, directory=str(REPO_ROOT)
+        )
+        handler.log_message = lambda *args: None
+        httpd = http.server.ThreadingHTTPServer(("127.0.0.1", 0), handler)
+        threading.Thread(target=httpd.serve_forever, daemon=True).start()
+        self.addCleanup(httpd.server_close)
+        self.addCleanup(httpd.shutdown)
+        (REPO_ROOT / "tmp").mkdir(exist_ok=True)
+        home = Path(tempfile.mkdtemp(dir=str(REPO_ROOT / "tmp")))
+        locked = home / "locked"
+        locked.mkdir()
+        locked.chmod(0o555)
+        self.addCleanup(shutil.rmtree, home, True)
+        self.addCleanup(locked.chmod, 0o755)
+        env = {
+            **os.environ,
+            "HOME": str(home),
+            "RETROBIOS_OS": "linux",
+            "RETROBIOS_BASE_URL": f"http://127.0.0.1:{httpd.server_address[1]}",
+        }
+        for dest in (locked / "sub", locked):
+            with self.subTest(dest=dest.name):
+                proc = subprocess.run(
+                    [sys.executable, "install.py", "--platform", "retroarch",
+                     "--dest", str(dest), "--system", "atari-lynx", "--no-input"],
+                    cwd=str(REPO_ROOT), env=env, capture_output=True, text=True,
+                    timeout=300, check=False,
+                )
+                self.assertEqual(proc.returncode, 2, proc.stdout + proc.stderr)
+
+
 if __name__ == "__main__":
     unittest.main()