fix: platform entries skip other emulators' trees

A platform entry names no profile, so bios/Other/<emulator>/ was never foreign to it. EmuELEC's ports/VVVVVV/data.zip resolved to xrick's data.zip, then to xrick's data directory copy. A system that lists its cores now takes no name match only another emulator's tree answers.

install/emuelec.json

@@ -20,11 +20,11 @@
     }
   ],
   "standalone_copies": [],
-  "total_files": 5297,
-  "total_size": 4143074421,
-  "pack_files": 9169,
-  "pack_size": 4257242836,
-  "total_omitted": 197,
+  "total_files": 5296,
+  "total_size": 4141616981,
+  "pack_files": 9168,
+  "pack_size": 4255785396,
+  "total_omitted": 198,
   "omitted_files": [
     {
       "dest": "FB Alpha 2012/hiscore.dat",
@@ -2070,6 +2070,18 @@
       ],
       "category": "game_data"
     },
+    {
+      "dest": "ports/VVVVVV/data.zip",
+      "name": "data.zip",
+      "system": "vvvvvv",
+      "required": true,
+      "reason": "not_found",
+      "cores": null,
+      "systems": [
+        "vvvvvv"
+      ],
+      "category": "game_data"
+    },
     {
       "dest": "ports/diablo/diabdat.mpq",
       "name": "diabdat.mpq",
@@ -8911,18 +8923,6 @@
       ],
       "category": "game_data"
     },
-    {
-      "dest": "ports/VVVVVV/data.zip",
-      "sha1": "ecfc092fe6371dbf38e238a8ba5f90785b5db52d",
-      "sha256": "2a86458696e83eb924fc6c6fda3ca5d320ca90885bd6c2f32d121757ade389bb",
-      "size": 1457440,
-      "repo_path": "bios/Other/xrick/data.zip",
-      "cores": null,
-      "systems": [
-        "vvvvvv"
-      ],
-      "category": "game_data"
-    },
     {
       "dest": "ports/xrick/data.zip",
       "sha1": "ecfc092fe6371dbf38e238a8ba5f90785b5db52d",

scripts/common.py

@@ -424,11 +424,24 @@ def load_platform_config(platform_name: str, platforms_dir: str = "platforms") -
 
     # Each entry carries the system that declares it: a hashless name match is
     # narrowed to the maker folder that system names (resolve_local_file).
+    # A system that names its own cores (EmuELEC, AmberELEC, KNULLI) also
+    # passes them on, so another emulator's tree is foreign to its entries.
     # Fresh dicts, since a YAML anchor can share one entry between systems.
     config["systems"] = {
         sys_id: {
             **system,
-            "files": [{**f, "platform_system": sys_id} for f in system["files"]],
+            "files": [
+                {
+                    **f,
+                    "platform_system": sys_id,
+                    **(
+                        {"platform_cores": list(system["cores"])}
+                        if system.get("cores")
+                        else {}
+                    ),
+                }
+                for f in system["files"]
+            ],
         }
         if isinstance(system, dict) and system.get("files")
         else system
@@ -1735,6 +1748,24 @@ def resolve_local_file(
                             continue
                         if os.path.exists(path) and path not in candidates:
                             candidates.append(path)
+        # A platform entry names no profile, but a system that lists its
+        # cores says whose files it asks for. A name only another emulator's
+        # tree answers is no evidence, and the data directories hold those
+        # emulators' trees too: EmuELEC's VVVVVV data.zip was served xrick's
+        # archive of the same name, then xrick's data directory copy.
+        core_owners = {
+            token
+            for core in file_entry.get("platform_cores") or ()
+            for token in _affinity_tokens(str(core))
+        }
+        if (
+            not owners
+            and core_owners
+            and candidates
+            and all(_foreign_tree(p, core_owners) for p in candidates)
+        ):
+            candidates = []
+            unsourceable = True
         if makers and candidates:
             candidates = [p for p in candidates if not other_maker(p, makers, db)]
             if not candidates:

scripts/generate_site.py

@@ -1035,13 +1035,18 @@ def _split_contract(config: dict) -> tuple[dict, dict]:
     """
     allowed = _contract_keys()
     contract = {key: value for key, value in config.items() if key in allowed}
-    # platform_system is the resolver's copy of the key each entry sits under.
+    # platform_system and platform_cores are the resolver's copies of the key
+    # each entry sits under and of that system's cores.
     if isinstance(contract.get("systems"), dict):
         contract["systems"] = {
             sys_id: {
                 **system,
                 "files": [
-                    {k: v for k, v in f.items() if k != "platform_system"}
+                    {
+                        k: v
+                        for k, v in f.items()
+                        if k not in ("platform_system", "platform_cores")
+                    }
                     for f in system["files"]
                 ],
             }

tests/test_game_data_homonyms.py

@@ -148,6 +148,72 @@ class AbsentFileIsNotReplacedByAHomonym(unittest.TestCase):
         self.assertEqual(self._resolve(), (None, "not_found"))
 
 
+class APlatformEntryTakesNoOtherEmulatorsTree(unittest.TestCase):
+    """A platform declaration names no profile, so another emulator's tree
+    was never foreign to it: EmuELEC's ports/VVVVVV/data.zip was served
+    xrick's data.zip, Rick Dangerous sounds, then xrick's data directory
+    copy. A system that lists its cores says whose files it asks for."""
+
+    def setUp(self):
+        import tempfile
+
+        import generate_db
+
+        self._tmp = tempfile.TemporaryDirectory()
+        self._cwd = os.getcwd()
+        os.chdir(self._tmp.name)
+        payload = b"rick dangerous"
+        target = Path("bios/Other/xrick/data.zip")
+        target.parent.mkdir(parents=True)
+        target.write_bytes(payload)
+        cache = Path("data/xrick/data.zip")
+        cache.parent.mkdir(parents=True)
+        cache.write_bytes(payload)
+        sha1 = hashlib.sha1(payload).hexdigest()
+        files = {sha1: {
+            "path": str(target), "name": "data.zip", "size": len(payload),
+            "sha1": sha1, "md5": hashlib.md5(payload).hexdigest(),
+            "sha256": hashlib.sha256(payload).hexdigest(), "crc32": "0",
+        }}
+        self.db = {"files": files, "indexes": generate_db.build_indexes(files, {})}
+        self.registry = {"xrick": {"local_cache": "data/xrick"}}
+
+    def tearDown(self):
+        os.chdir(self._cwd)
+        self._tmp.cleanup()
+
+    def _resolve(self, **fields):
+        entry = {"name": "data.zip", "destination": "ports/VVVVVV/data.zip",
+                 "platform_system": "vvvvvv", **fields}
+        return resolve_local_file(
+            entry, self.db, {}, dest_hint=entry["destination"],
+            data_dir_registry=self.registry,
+        )
+
+    def test_a_system_naming_other_cores_gets_nothing(self):
+        self.assertEqual(self._resolve(platform_cores=["VVVVVV"]), (None, "not_found"))
+
+    def test_the_owners_own_system_still_gets_it(self):
+        self.assertEqual(
+            self._resolve(platform_cores=["xrick"]),
+            ("bios/Other/xrick/data.zip", "name_exact"),
+        )
+
+    def test_the_emuelec_entry_is_not_served_xrick(self):
+        os.chdir(self._cwd)
+        from common import load_platform_config
+
+        config = load_platform_config("emuelec", str(REPO_ROOT / "platforms"))
+        entry = config["systems"]["vvvvvv"]["files"][0]
+        self.assertEqual(entry["platform_cores"], ["VVVVVV"])
+        db = load_database(str(REPO_ROOT / "database.json"))
+        path, _status = resolve_local_file(
+            entry, db, {}, dest_hint=entry["destination"],
+            data_dir_registry=load_data_dir_registry(str(REPO_ROOT / "platforms")),
+        )
+        self.assertFalse(path and "xrick" in path, path)
+
+
 class SecondPassKeepsIdentity(unittest.TestCase):
     """A copy of a covered file at another core's path keeps the entry's proof.