From bd22951874a7d9de03850f3da79d7ed668eebc8a Mon Sep 17 00:00:00 2001
From: zagatozee <33841901+zagatozee@users.noreply.github.com>
Date: Thu, 4 Jun 2026 22:40:40 +0100
Subject: [PATCH] feed the rabbit

Updated the docstring for _load_gpif to clarify supported file formats and improved error messages for unrecognized containers.L

(cherry picked from commit 1866c72e53339a10d6f184d21c2261e9f0b21395)
---
 lib/gp2rs_gpx.py | 37 ++++++++++++++++++++++++++++++-------
 1 file changed, 30 insertions(+), 7 deletions(-)

diff --git a/lib/gp2rs_gpx.py b/lib/gp2rs_gpx.py
index 3e1f8d1..dc37a22 100644
--- a/lib/gp2rs_gpx.py
+++ b/lib/gp2rs_gpx.py
@@ -133,15 +133,35 @@ def _parse_bcfs(bcfs: bytes) -> dict:
 
 
 def _load_gpif(gp_path: str) -> ET.Element:
-    """Load and parse score.gpif from a .gpx file."""
+    """Load and parse score.gpif from a .gpx (GP6) or .gp (GP7/GP8) file.
+
+    GP6 (.gpx): custom BCFZ/BCFS binary container holding score.gpif.
+    GP7/GP8 (.gp): standard ZIP archive holding Content/score.gpif.
+    Both formats use the same GPIF XML schema inside, so a single parser
+    handles all versions once the outer container is unpacked.
+    """
     with open(gp_path, 'rb') as fh:
         raw = fh.read()
+
+    # GP7/GP8: ZIP container (PK magic)
+    if raw[:2] == b'PK':
+        import zipfile
+        import io as _io
+        with zipfile.ZipFile(_io.BytesIO(raw)) as zf:
+            if 'Content/score.gpif' not in zf.namelist():
+                raise ValueError("Content/score.gpif not found in GP7/GP8 ZIP container")
+            return ET.fromstring(zf.read('Content/score.gpif'))
+
+    # GP6 (.gpx): BCFZ compressed or raw BCFS
     if raw[:4] == b'BCFZ':
         bcfs = _decompress_bcfz(raw)
     elif raw[:4] == b'BCFS':
         bcfs = raw
     else:
-        raise ValueError(f"Not a GPX file (magic: {raw[:4]!r})")
+        raise ValueError(
+            f"Unrecognised Guitar Pro container (magic: {raw[:4]!r}). "
+            f"Supported: .gpx (GP6, BCFZ/BCFS) and .gp (GP7/GP8, ZIP)."
+        )
     fs = _parse_bcfs(bcfs)
     if 'score.gpif' not in fs:
         raise ValueError("score.gpif not found in GPX container")
@@ -589,7 +609,8 @@ def list_tracks(gp_path: str) -> list[dict]:
                 and not t['string_pitches']  # no string tuning = not guitar-family
                 and 32 <= t['midi_program'] <= 39
             ) or (
-                t['string_pitches']
+                not t['is_drums']  # explicit guard: drums can have low string pitches
+                and t['string_pitches']
                 and max(t['string_pitches']) <= 48  # bass top string ≤ C3
             )
         )
@@ -1400,7 +1421,7 @@ def convert_file(
                                     )
                                     # Staff assignment for keys/piano (slopsmith staff schema).
                                     # Derived from voice position as authored in the GP tab —
-                                    # not inferred from pitch — preserving hand crossings exactly.
+                                    # not inferred from pitch — preserving hand crossings.
                                     # Voice 0 = treble/RH staff (staff=1),
                                     # Voice 1+ = bass/LH staff (staff=0).
                                     if is_keys:
@@ -1589,7 +1610,7 @@ def convert_file(
                 if _lh_bid != '-1' and _lh_bid:
                     _lh_bar = bars_by_id.get(_lh_bid)
                     if _lh_bar is not None:
-                        for _lh_voice_pos, _lh_vid in enumerate(_lh_bar.findtext('Voices', '').split()):
+                        for _lh_vid in _lh_bar.findtext('Voices', '').split():
                             if _lh_vid == '-1':
                                 continue
                             _lh_voice = voices_dict.get(_lh_vid)
@@ -1639,8 +1660,10 @@ def convert_file(
                                         fret=_lh_midi % 24,
                                         sustain=_lh_dur if _lh_dur > 0.2 else 0.0,
                                     )
-                                    # Preserve authored voice-position staff assignment.
-                                    _lh_rn.staff = 1 if _lh_voice_pos == 0 else 0
+                                    # LH track notes are always bass clef (staff=0).
+                                    # The LH track as a whole IS the left hand —
+                                    # voice position within the LH track is irrelevant.
+                                    _lh_rn.staff = 0
                                     _lh_notes.append(_lh_rn)
                                     _lh_last_per_key[_lh_midi] = _lh_rn
                                 _lh_vt += _lh_dur