fix: give no second-pass copy to unsourceable files

scripts/packextras.py

@@ -604,8 +604,10 @@ def _collect_emulator_extras(
             fname = f.get("name", "")
             if not fname:
                 continue
-            # Only duplicate files already covered at another destination
-            if fname not in covered_names:
+            # Only duplicate files already covered at another destination.
+            # An unsourceable entry is a file no collection holds: the name
+            # covered elsewhere belongs to another program's file.
+            if fname not in covered_names or f.get("unsourceable"):
                 continue
             file_mode = f.get("mode")
             if file_mode == "standalone" and not is_standalone:

tests/test_extra_identity.py

@@ -62,5 +62,40 @@ class IdentityTravels(unittest.TestCase):
         self.assertIn("validation", PROFILE_IDENTITY_FIELDS)
 
 
+class UnsourceableIsNoCopy(unittest.TestCase):
+    """The second pass copies a covered file to another core's path by name.
+
+    zc210 ships its own default.sf2; dosbox-staging reads a default.sf2 that
+    the operating system links to its SoundFont, which no collection holds.
+    The name was enough to give dosbox-staging a slot, recorded as missing
+    while zc210 was in the pack and absent once it was not, so a pack built
+    for a target disagreed with the installer narrowing the full list.
+    """
+
+    def test_an_unsourceable_entry_gets_no_copy(self):
+        profiles = {
+            "zc210": {"emulator": "ZC", "type": "libretro", "systems": ["zc"],
+                      "files": [{"name": "default.sf2", "path": "zc210/sf2/default.sf2"}]},
+            "dosbox-staging": {
+                "emulator": "DOSBox Staging", "type": "libretro", "systems": ["dos"],
+                "files": [{"name": "default.sf2", "path": "soundfonts/default.sf2",
+                           "required": False, "unsourceable": "the system's own link"}],
+            },
+        }
+        config = {"cores": ["zc210", "dosbox-staging"], "systems": {}}
+        db = {
+            "files": {"s1": {"name": "default.sf2", "path": "bios/ZC/default.sf2",
+                             "size": 10, "sha1": "s1", "md5": "m1", "crc32": "c1"}},
+            "indexes": {"by_name": {"default.sf2": ["s1"]}, "by_md5": {"m1": "s1"},
+                        "by_crc32": {"c1": "s1"},
+                        "by_path_suffix": {"zc210/sf2/default.sf2": ["s1"]}},
+        }
+        extras = _collect_emulator_extras(config, "emulators", db, set(), "", profiles)
+        self.assertEqual(
+            [(e["source_profile"], e["destination"]) for e in extras],
+            [("zc210", "zc210/sf2/default.sf2")],
+        )
+
+
 if __name__ == "__main__":
     unittest.main()

tests/test_game_data_homonyms.py

@@ -153,7 +153,8 @@ class SecondPassKeepsIdentity(unittest.TestCase):
     The second extras pass copied a name the baseline already covers to the
     profile's own path, without its hashes or its `unsourceable:` flag, so
     the copy resolved on the name: RetroBat's pack carried Quake III's
-    baseq3/pak1.pk3 as MOHAA's mainta/pak1.pk3.
+    baseq3/pak1.pk3 as MOHAA's mainta/pak1.pk3. An unsourceable entry is
+    settled, as the first pass treats it, and gets no copy.
     """
 
     def test_flag_and_hashes_reach_the_alternative_destination(self):
@@ -182,7 +183,8 @@ class SecondPassKeepsIdentity(unittest.TestCase):
         }}
         extras = {e["destination"]: e for e in _collect_emulator_extras(
             config, "emulators", db, set(), "", profiles)}
-        self.assertEqual(extras["mainta/pak1.pk3"].get("unsourceable"), "retail")
+        # Unsourceable is settled, as in the first pass: no copy at all.
+        self.assertNotIn("mainta/pak1.pk3", extras)
         self.assertEqual(extras["maintt/pak1.pk3"].get("sha1"), "c" * 40)