fix: keep Batocera's save files apart from bios/

batocera-systems lists bios/saves/dolphin-emu/Triforce/segaboot.gcm, so the pack folder for the save directory is userdata-saves/. validate_schemas refuses a pack folder the BIOS tree already uses.

platforms/_registry.yml

@@ -499,11 +499,14 @@ platforms:
     # libretroConfig.py:225-228 and batoceraPaths.py:22 at batocera-43.1).
     # <system> is the ES system name (Emulator.py:119, args.system), so a
     # file is placed once below each system es_systems.yml offers the core
-    # for (libretro_systems in batocera.yml).
+    # for (libretro_systems in batocera.yml). The pack keeps them in
+    # userdata-saves/: batocera-systems lists bios/saves/dolphin-emu/
+    # Triforce/segaboot.gcm, so saves/ already belongs to the BIOS tree.
     save_directory:
       folder: saves
       by_core: false
       by_system: true
+      pack_folder: userdata-saves
     schedule: weekly
     target_scraper: batocera_targets
     target_source: https://github.com/batocera-linux/batocera.linux

scripts/generate_pack.py

@@ -1191,7 +1191,7 @@ def generate_pack(
               _pack_registry.get(platform_name, {}).get("install", {}) or {}
           ).get("standalone_copies", []),
           launch_folders=len(config.get("core_system_dirs") or {}),
-          save_folder=(save_layout(config).folder if save_count else ""),
+          save_folder=(save_layout(config).in_pack if save_count else ""),
           save_where=(
               save_place(
                   str(_pack_registry.get(platform_name, {}).get("extract_to") or ""),

scripts/packextras.py

@@ -1371,7 +1371,7 @@ def _save_fields(extra: dict, pack_path: str, placement: ExtraPlacement) -> None
     extra["pack_path"] = pack_path
     if placement.save is not None:
         # The path below the save directory, what the manifest writes.
-        extra["save_dest"] = pack_path[len(placement.save.folder) + 1:]
+        extra["save_dest"] = pack_path[len(placement.save.in_pack) + 1:]
         if not placement.save.by_core:
             extra.pop("core_folder", None)
 

scripts/packpaths.py

@@ -31,13 +31,23 @@ class SaveLayout:
     /userdata/saves/<system>): a file read there is placed once for each
     system that runs the core, the systems the platform file names in
     ``libretro_systems``. ``by_core_for`` names the cores a launcher
-    sorts by core where it sorts no other.
+    sorts by core where it sorts no other. ``pack_folder`` renames the
+    pack's folder when the BIOS tree holds one of the same name.
     """
 
     folder: str
     by_core: bool
     by_system: bool = False
     by_core_for: frozenset[str] = frozenset()
+    pack_folder: str = ""
+
+    @property
+    def in_pack(self) -> str:
+        """The pack folder holding these files: ``pack_folder`` where the
+        platform's own BIOS tree already has a folder named ``folder``
+        (Batocera lists bios/saves/dolphin-emu/Triforce/segaboot.gcm),
+        ``folder`` otherwise."""
+        return self.pack_folder or self.folder
 
     def sorts(self, names: Iterable[str]) -> bool:
         """Whether the frontend inserts the core's folder for a core known
@@ -64,6 +74,7 @@ def save_layout(config: dict) -> SaveLayout | None:
     return SaveLayout(
         folder, bool(block.get("by_core")), bool(block.get("by_system")),
         frozenset(str(core) for core in block.get("by_core_for") or []),
+        sanitize_pack_path(str(block.get("pack_folder") or "")),
     )
 
 
@@ -85,7 +96,7 @@ def save_destination(
     rel = sanitize_pack_path(path)
     if not rel:
         return None
-    root = layout.folder
+    root = layout.in_pack
     if layout.by_system:
         folder = sanitize_pack_path(system)
         if not folder or "/" in folder:

scripts/validate_schemas.py

@@ -416,8 +416,10 @@ def _save_directory_blocks() -> list[str]:
         if (
             not isinstance(block, dict)
             or not {"folder", "by_core"} <= set(block) <= {
-                "folder", "by_core", "by_system", "by_core_for",
+                "folder", "by_core", "by_system", "by_core_for", "pack_folder",
             }
+            or not isinstance(block.get("pack_folder", "x"), str)
+            or "/" in str(block.get("pack_folder", ""))
             or not isinstance(folder, str)
             or not folder
             or "\\" in folder
@@ -438,9 +440,37 @@ def _save_directory_blocks() -> list[str]:
                 f"platforms/_registry.yml: {name}.save_directory.by_system and "
                 f"platforms/{name}.yml lists no libretro_systems"
             )
+        in_pack = block.get("pack_folder") or folder
+        taken = _bios_tree_below(name, in_pack)
+        if taken:
+            out.append(
+                f"platforms/_registry.yml: {name}.save_directory puts the save "
+                f"files in {in_pack}/, which the BIOS tree uses ({taken}): "
+                "name another pack_folder"
+            )
     return out
 
 
+def _bios_tree_below(platform: str, folder: str) -> str:
+    """A destination the platform declares below ``folder``, or empty."""
+    from common import load_platform_config
+
+    try:
+        config = load_platform_config(platform, str(ROOT / "platforms"))
+    except FileNotFoundError:
+        return ""
+    prefix = f"{folder}/".lower()
+    return next(
+        (
+            str(entry["destination"])
+            for system in (config.get("systems") or {}).values()
+            for entry in system.get("files") or []
+            if str(entry.get("destination") or "").lower().startswith(prefix)
+        ),
+        "",
+    )
+
+
 def _libretro_systems(platform: str) -> dict:
     """The platform file's core -> systems table, inheritance included."""
     from common import load_platform_config

tests/test_save_root.py

@@ -134,7 +134,7 @@ class ThePlatformNamesItsSaveDirectory(unittest.TestCase):
 
         platforms = str(REPO_ROOT / "platforms")
         expected = {
-            "batocera": SaveLayout("saves", False, True),
+            "batocera": SaveLayout("saves", False, True, pack_folder="userdata-saves"),
             "knulli": SaveLayout("saves", False, True),
             "recalbox": SaveLayout("saves", False, True),
             "retrodeck": SaveLayout("saves", False, True),
@@ -168,6 +168,25 @@ class ThePlatformNamesItsSaveDirectory(unittest.TestCase):
             "saves/wii/dolphin-emu/User/GBA/gba_bios.bin",
         )
 
+    def test_a_pack_folder_apart_from_the_bios_tree(self):
+        """Batocera's BIOS tree has a saves/ of its own: the pack keeps the
+        save directory's files in another folder, the installer still
+        writes them to /userdata/saves."""
+        layout = save_layout({"save_directory": {
+            "folder": "saves", "by_core": False, "by_system": True,
+            "pack_folder": "userdata-saves"}})
+        self.assertEqual(layout.in_pack, "userdata-saves")
+        self.assertEqual(save_destination("stella/KVS1.WAV", None, layout, "atari2600"),
+                         "userdata-saves/atari2600/stella/KVS1.WAV")
+        self.assertEqual(SaveLayout("saves", True).in_pack, "saves")
+        try:
+            from validate_schemas import _bios_tree_below
+        except ImportError:
+            self.skipTest("validate_schemas needs jsonschema")
+        self.assertEqual(_bios_tree_below("batocera", "saves"),
+                         "saves/dolphin-emu/Triforce/segaboot.gcm")
+        self.assertEqual(_bios_tree_below("batocera", "userdata-saves"), "")
+
     def test_the_systems_a_core_runs_for(self):
         from packpaths import libretro_systems
 

wiki/adding-a-platform.md

@@ -304,6 +304,8 @@ that text belongs in a guide field.
                                      # (Batocera, RetroBat): one copy per system in the
                                      # platform file's libretro_systems
       by_core_for: [dolphin]         # cores the launcher alone sorts by core (RetroBat)
+      pack_folder: userdata-saves    # the pack's folder for them, where the BIOS tree
+                                     # already has one named like folder (Batocera)
                                      # null when saves sit beside each game
     zip_digest: composite            # the frontend hashes a .zip by its members only
     firmware_folder_flat: true       # the frontend lists each system folder without