feat: find the RetroArch AppImage portable home

install.ps1

@@ -16,7 +16,7 @@
     # and Invoke-WebRequest throws on a cut transfer before the hash is read:
     # the site's build rewrites this line there (scripts/sitebootstrap.py).
     $mismatchAdvice = "The download was most likely cut short: try again. Within minutes of an update of this project the two files can come from caches of different ages. Waiting five minutes settles that."
-    $defaultInstallSha256 = "450cee7625f098d5796452b02ab9c8bffdeaaef89180d2254bbe07ce354bc359"
+    $defaultInstallSha256 = "5bce9f0f81e4f1c7302ca78fa5242f26acc06523f8718378ee97042f2421ff78"
     $maximumInstallerBytes = 2MB
     $installerExit = 0
     $installer = if ($PSScriptRoot) { Join-Path $PSScriptRoot "install.py" } else { $null }

install.py

@@ -1401,6 +1401,49 @@ def _macos_retroarch_base() -> Path:
     return Path.home() / "Documents" / "RetroArch"
 
 
+def _retroarch_appimage_dirs(home: Path) -> list[Path]:
+    """The system folder of each RetroArch AppImage kept with a portable
+    folder, up to two folders below home.
+
+    The buildbot's Linux build unpacks RetroArch-Linux-x86_64.AppImage beside
+    RetroArch-Linux-x86_64.AppImage.home/.config/retroarch. The AppImage
+    runtime sets HOME to <AppImage>.home and XDG_CONFIG_HOME to
+    <AppImage>.config when those folders exist (type2-runtime fedfad51,
+    src/runtime/runtime.c:1449-1462), so this RetroArch never reads
+    ~/.config/retroarch. The archive holds no retroarch.cfg: until the first
+    run writes one, the system folder is the base folder's (frontend_unix_get_env
+    in platform_unix.c).
+    """
+    images: list[Path] = []
+    for depth in ("", "*/", "*/*/"):
+        for suffix in (".home", ".config"):
+            try:
+                hits = sorted(home.glob(f"{depth}*.AppImage{suffix}"))
+            except OSError:
+                continue
+            for hit in hits:
+                image = hit.with_name(hit.name[:-len(suffix)])
+                if image not in images and _is_file(image):
+                    images.append(image)
+    dirs: list[Path] = []
+    for image in images:
+        portable_home = image.with_name(image.name + ".home")
+        portable_config = image.with_name(image.name + ".config")
+        if _is_dir(portable_config):
+            base = portable_config / "retroarch"
+        elif _is_dir(portable_home) and "XDG_CONFIG_HOME" not in os.environ:
+            base = portable_home / ".config" / "retroarch"
+        else:
+            continue
+        tilde = portable_home if _is_dir(portable_home) else home
+        system = _parse_retroarch_system_dir(base / "retroarch.cfg", base, tilde)
+        if system is None and _is_dir(base):
+            system = base / "system"
+        if system is not None and system not in dirs:
+            dirs.append(system)
+    return dirs
+
+
 def _unix_retroarch_base() -> Path:
     """RetroArch's base folder on Linux: $XDG_CONFIG_HOME/retroarch when the
     variable is set, else ~/.config/retroarch (fill_pathname_application_data
@@ -2839,6 +2882,8 @@ def detect_platforms(os_type: str) -> list[tuple[str, Path]]:
                 found.append(("retroarch", ra_dir))
                 break
 
+        found.extend(("retroarch", ra_dir) for ra_dir in _retroarch_appimage_dirs(home))
+
     if os_type == "darwin":
         # open_default_config_file reads <Application Support>/RetroArch/config
         # (configuration.c). A value left at default is the documents folder,

install.sh

@@ -23,7 +23,7 @@ DEFAULT_INSTALL_URL="https://raw.githubusercontent.com/Abdess/retrobios/main/ins
 # curl or wget stop on a cut transfer before the hash is read: the site's
 # build rewrites this line there (scripts/sitebootstrap.py).
 MISMATCH_ADVICE="The download was most likely cut short: try again. Within minutes of an update of this project the two files can come from caches of different ages. Waiting five minutes settles that."
-DEFAULT_INSTALL_SHA256="450cee7625f098d5796452b02ab9c8bffdeaaef89180d2254bbe07ce354bc359"
+DEFAULT_INSTALL_SHA256="5bce9f0f81e4f1c7302ca78fa5242f26acc06523f8718378ee97042f2421ff78"
 MAX_INSTALLER_BYTES=2097152
 
 cleanup() {

install/launchers/index.json

@@ -27,8 +27,8 @@
         {
           "dest": "roms/ports/retrobios/install.py",
           "repo_path": "install.py",
-          "size": 1115328,
-          "sha256": "450cee7625f098d5796452b02ab9c8bffdeaaef89180d2254bbe07ce354bc359",
+          "size": 1117350,
+          "sha256": "5bce9f0f81e4f1c7302ca78fa5242f26acc06523f8718378ee97042f2421ff78",
           "executable": false
         },
         {
@@ -71,8 +71,8 @@
     "muos": {
       "archive": {
         "dest": "ARCHIVE/RetroBIOS.muxapp",
-        "size": 1168955,
-        "sha256": "1f52731fda2beb3ff9e7aaf7f3d9333853e66b99240b24e4f6b0026368755cb4"
+        "size": 1170977,
+        "sha256": "cfb61e90dafef4fceadd8750412fe91a98b5d8cbf9574c819c09bddb76486e78"
       },
       "members": [
         {
@@ -92,8 +92,8 @@
         {
           "name": "RetroBIOS/install.py",
           "repo_path": "install.py",
-          "size": 1115328,
-          "sha256": "450cee7625f098d5796452b02ab9c8bffdeaaef89180d2254bbe07ce354bc359",
+          "size": 1117350,
+          "sha256": "5bce9f0f81e4f1c7302ca78fa5242f26acc06523f8718378ee97042f2421ff78",
           "executable": false
         },
         {
@@ -166,8 +166,8 @@
         {
           "dest": ".config/modules/retrobios/install.py",
           "repo_path": "install.py",
-          "size": 1115328,
-          "sha256": "450cee7625f098d5796452b02ab9c8bffdeaaef89180d2254bbe07ce354bc359",
+          "size": 1117350,
+          "sha256": "5bce9f0f81e4f1c7302ca78fa5242f26acc06523f8718378ee97042f2421ff78",
           "executable": false
         },
         {

tests/test_install.py

@@ -4542,6 +4542,53 @@ class WindowsSeenFromWsl(unittest.TestCase):
                          str(self.root))
 
 
+class RetroArchAppImageIsPortable(unittest.TestCase):
+    """The buildbot's Linux RetroArch is an AppImage beside a .home folder
+    the AppImage runtime makes its HOME: the run found nothing and offered
+    ~/.config/retroarch/system, a folder this RetroArch never reads."""
+
+    def _detect(self, home: Path, env: dict | None = None) -> list:
+        cleared = {"HOME": str(home), "XDG_CONFIG_HOME": ""}
+        with unittest.mock.patch.dict(os.environ, {**cleared, **(env or {})}), \
+                unittest.mock.patch.object(Path, "home", return_value=home):
+            os.environ.pop("XDG_CONFIG_HOME")
+            return install.detect_platforms("linux")
+
+    def _unpack(self, home: Path) -> Path:
+        folder = home / "Downloads" / "RetroArch-Linux-x86_64"
+        base = folder / "RetroArch-Linux-x86_64.AppImage.home" / ".config" / "retroarch"
+        (base / "system").mkdir(parents=True)
+        (folder / "RetroArch-Linux-x86_64.AppImage").write_bytes(b"\x7fELF")
+        return base
+
+    def test_the_unpacked_archive_is_found(self):
+        home = Path(_tempdir(self))
+        base = self._unpack(home)
+        self.assertIn(("retroarch", base / "system"), self._detect(home))
+
+    def test_its_config_is_read_with_its_own_home(self):
+        home = Path(_tempdir(self))
+        base = self._unpack(home)
+        (base / "retroarch.cfg").write_text('system_directory = "~/bios"\n')
+        portable = base.parent.parent
+        self.assertIn(("retroarch", portable / "bios"), self._detect(home))
+
+    def test_a_config_folder_beside_it_wins(self):
+        home = Path(_tempdir(self))
+        base = self._unpack(home)
+        config = base.parent.parent.with_name("RetroArch-Linux-x86_64.AppImage.config")
+        (config / "retroarch").mkdir(parents=True)
+        found = self._detect(home)
+        self.assertIn(("retroarch", config / "retroarch" / "system"), found)
+        self.assertNotIn(("retroarch", base / "system"), found)
+
+    def test_a_folder_without_its_appimage_is_left(self):
+        home = Path(_tempdir(self))
+        base = self._unpack(home)
+        (base.parent.parent.with_name("RetroArch-Linux-x86_64.AppImage")).unlink()
+        self.assertNotIn(("retroarch", base / "system"), self._detect(home))
+
+
 class SteamRetroArchOnMacIsPortable(unittest.TestCase):
     """platform_darwin.m makes the Steam build portable (HAVE_STEAM) with no
     portable.txt: a default system_directory is Application Support's, and

wiki/installer.md

@@ -1177,6 +1177,7 @@ usual folders of a setup that has one on each side: RetroArch's in this Linux
 | `~/.var/app/org.libretro.RetroArch/config/retroarch/retroarch.cfg` | RetroArch (Flatpak) | `system_directory` |
 | `~/snap/retroarch/current/.config/retroarch/retroarch.cfg` | RetroArch (Snap) | `system_directory` |
 | `~/.config/retroarch/retroarch.cfg` | RetroArch (native) | `system_directory` |
+| `<name>.AppImage.home/.config/retroarch/retroarch.cfg` (or `<name>.AppImage.config/retroarch/`) beside an AppImage in `~`, or one or two folders below it | RetroArch (AppImage from the buildbot, whose portable folder becomes its home) | `system_directory`. Without a config, `system` in that `retroarch` folder |
 | `~/Library/Application Support/RetroArch/config/retroarch.cfg` | RetroArch (macOS) | `system_directory`. At default, `~/Documents/RetroArch/system` (portable, Steam build included: `Application Support/RetroArch/system`) |
 | `retroarch.cfg` beside `retroarch.exe` (`C:\RetroArch-Win64`, `C:\RetroArch`, `Program Files\RetroArch`) | RetroArch (Windows) | `system_directory`. At default or without a config, `system` beside the exe |
 | `%APPDATA%\RetroArch\retroarch.cfg` | RetroArch (Windows) | `system_directory`, read when the exe folder has no config |