fix: keep scan copies out of region choices

scripts/packextras.py

@@ -893,7 +893,12 @@ def platform_region_groups(
                 extra.get("source_path", ""),
             )
         ] = dest
-        for group_id in extra_region_groups(extra):
+        # A file a filename-agnostic scan accepts by shape competes only if
+        # its seed names a region: PCSX2 picks no PS2 BIOS by territory, and
+        # looked up by name its scph50006 took DuckStation's [japan], which
+        # describes DuckStation's own PS1-on-PS2 choice.
+        competes = not extra.get("agnostic_scan") or extra.get("region")
+        for group_id in extra_region_groups(extra) if competes else ():
             groups.setdefault(group_id, []).append((dest, name))
         if extras_out is not None:
             extras_out.append(extra)

tests/test_region_agnostic_scan.py

@@ -0,0 +1,54 @@
+"""A file an agnostic scan accepts by shape keeps out of region choices.
+
+PCSX2 picks no PS2 BIOS by territory, yet the copies its scan put under
+pcsx2/bios/ were looked up by name and took DuckStation's region, which
+describes DuckStation's own PS1-on-PS2 choice: `--region eu` withdrew
+pcsx2/bios/ps2_scph50006.bin from RetroArch, Lakka, RetroPie, RetroDECK and
+ROCKNIX. Reads the repository: skips when the database is absent.
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+import unittest
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO_ROOT / "scripts"))
+
+
+class ScanCopiesStay(unittest.TestCase):
+    def test_no_scan_copy_is_withdrawn(self):
+        if not (REPO_ROOT / "database.json").exists():
+            self.skipTest("database.json is not built")
+        previous = os.getcwd()
+        os.chdir(REPO_ROOT)
+        self.addCleanup(os.chdir, previous)
+        import region as region_mod
+        from common import load_database, load_emulator_profiles, load_platform_config
+        from packextras import platform_region_groups
+
+        db = load_database("database.json")
+        profiles = load_emulator_profiles("emulators")
+        config = load_platform_config("retroarch")
+        extras: list[dict] = []
+        groups, _ = platform_region_groups(
+            config, config["systems"], "emulators", db,
+            config.get("base_destination", ""), profiles, extras_out=extras,
+        )
+        scanned = {
+            e["destination"] for e in extras
+            if e.get("agnostic_scan") and not e.get("region")
+        }
+        if not scanned:
+            self.skipTest("no agnostic scan copy in the RetroArch pack")
+        index = region_mod.platform_region_index(config, profiles)
+        for regions in (["europe"], ["japan"], ["north-america"]):
+            with self.subTest(regions=regions):
+                drops = region_mod.resolve_region_drops(groups, index, regions)
+                self.assertEqual(sorted(drops & scanned), [])
+
+
+if __name__ == "__main__":
+    unittest.main()