The merge window kept reporting "Order kept from this machine (most recently
edited)" for playlists edited on the other machine. Three defects, confirmed
against the real snapshots in .resolved/:
* "this machine" was inferred from which copy held the plain filename. That is
Syncthing's call, not a statement about authorship — it sets the local copy
aside as readily as a remote one. In the 9:34 PM `* a fresh master` merge the
copy labelled "the other machine" was this machine's own 3:15 PM merge output,
so the label was exactly backwards. The 7-char device ID in the conflict
filename — the only real evidence — was matched by a bare \w+ and deleted with
the file. New sync_identity.py decodes it against Syncthing's config.xml and
works out which device is us from cert.pem.
* The decision leaned local. date_modified was only consulted when *both* copies
had one, and an iTunes playlist never reordered here has none — so the honest
comparison was skipped exactly when one machine had edited and the other
hadn't. A stamped copy now beats an unstamped one; mtime is the fallback only
when neither side has ever been edited. And every merge used to rewrite the
file it kept whether or not anything changed, freshening its mtime while the
conflict file kept its origin's: a ratchet. No-op merges write nothing, and a
merge whose result is a union neither copy had stamps date_modified, so the
other machine adopts it instead of trading the same 19 tracks back and forth.
* Nothing was actionable. Re-inserted tracks are now named with their position
("Pola — Abeille -> position 24, after ..."), six in the window and all of
them in what-changed.txt at the top of the backup snapshot, alongside the real
conflict filename and its device. Tracks only this copy has are reported too
rather than resurrected in silence.
Also fixed while in here: a rename or folder move made elsewhere was discarded
by every merge (only track_ids and settings were adopted); _reconcile_playlist
asserted the local edit was newer and never checked, so a reorder synced in from
the other machine was undone and flushed back to disk, and the branch reaching
it was gated on a dirty flag that a column drag sets; and _merge_metadata
decided the music folder from whichever copy an mtime coin flip had kept.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y9ZEFi4qNJ39FMiBtiAxy2
What scrambled `a nissa one` took three defects at once. Reorder it on machine
A; open it on machine B and resize the window; B's file is now newer, so the
merge takes B's order — the old one — wholesale.
_merge_playlist was a 2-way union with no common ancestor: one side's order
wholesale, the other side's extras appended at the tail, so a track inserted in
the middle on one machine arrived at the bottom on the other. merge_track_order
re-inserts each side-only track after the nearest track both copies share
instead. _reconcile_playlist (the live-reload path) uses the same helper. The
union invariant is unchanged and property-tested over 300 random pairs — a
merge never drops a track.
Whose order wins is now Playlist.date_modified, bumped only in _set_track_ids
(add / remove / reorder / undo) and deliberately not by
mark_playlist_settings_dirty, with a file-mtime fallback for playlists written
before the field existed. The file's mtime was a lie: the last column is
stretch-sized, so Qt re-fires sectionResized whenever the viewport width
changes, and a window resize or splitter drag rewrote the open playlist's JSON
— moving its mtime and handing Syncthing another conflict — for a width
apply_settings overrides on load anyway. _on_section_resized now skips that
section; genuine drags on every other column still persist.
Replayed on a copy of the real playlists: `a nissa one` keeps its reorder
against a newer-by-mtime opponent, and `a nissa ideas` takes the other
machine's two mid-list inserts at 5 and 12 rather than 26 and 27.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M8Mzze7shr5pZoEgKQU5NW
travandClaude Opus 5