Normalize drum part pointer identities

lib/sloppak.py

@@ -790,14 +790,23 @@ def _resolve_drum_parts(
     primary_name = None
     extra_parts: list[dict] = []
     seen_rels: set[str] = set()
+    # Use the same canonical, traversal-safe identity as zip member lookup so
+    # equivalent spellings ("x.json", "./x.json", or backslashes) identify
+    # one file. Otherwise an alias pointer can reload and duplicate the primary.
+    primary_rel_key = (
+        _zip_member_key(drum_tab_rel.strip())
+        if isinstance(drum_tab_rel, str) and drum_tab_rel.strip() else None
+    )
     for entry in drum_pointer_entries:
         rel = str(entry.get("drum_tab") or "").strip()
-        if not rel or rel in seen_rels:
+        rel_key = _zip_member_key(rel) if rel else None
+        rel_identity = rel_key or rel
+        if not rel or rel_identity in seen_rels:
             continue
-        seen_rels.add(rel)
+        seen_rels.add(rel_identity)
         entry_id = str(entry.get("id") or "").strip()
         entry_name = str(entry.get("name") or "").strip()
-        if isinstance(drum_tab_rel, str) and rel == drum_tab_rel.strip():
+        if primary_rel_key is not None and rel_key == primary_rel_key:
             if entry_id:
                 primary_id = entry_id
             if entry_name:

tests/test_sloppak_drum_parts.py

@@ -118,6 +118,24 @@ def test_two_parts_resolve_primary_first_with_alias_identity(tmp_path: Path):
     assert loaded.drum_parts[1]["drum_tab"]["hits"][0]["t"] == 2.0
 
 
+def test_primary_pointer_equivalent_path_is_not_duplicated(tmp_path: Path):
+    manifest = {
+        "drum_tab": "drum_tab.json",
+        "arrangements": [
+            {"id": "lead", "name": "Lead", "file": "arrangements/lead.json"},
+            {"id": "kit", "name": "Live Kit", "type": "drums",
+             "drum_tab": "./drum_tab.json"},
+        ],
+    }
+    pak = _write_pak(tmp_path, manifest, {"drum_tab.json": _tab("Drums")})
+    loaded = _load(pak, tmp_path)
+    assert loaded.drum_parts is not None
+    assert [(p["id"], p["name"]) for p in loaded.drum_parts] == [
+        ("kit", "Live Kit"),
+    ]
+    assert loaded.drum_parts[0]["drum_tab"] is loaded.drum_tab
+
+
 def test_legacy_single_drum_pack_gets_a_one_part_list(tmp_path: Path):
     pak = _write_pak(tmp_path, {"drum_tab": "drum_tab.json"}, {
         "drum_tab.json": _tab("Drums"),