Review of the #233 implementation found two correctness defects. Both
are cases where the FIRST fix for #233 was itself wrong, which is worth
naming: this lane repaired absolute globs and, in the same change, broke
a case that had worked since May.
P1 --- `resolve_watcher` returned "absolute" for EVERY string, so the
form was carried but derived from the union arm rather than from the
pattern. A bare `*.txt` is a valid relative pattern (LSP 3.17 defines
`Pattern` relative to a base path; VS Code treats string watchers as
applying across workspace folders), and classifying it absolute matched
it against `<base>/foo.txt`, which `^[^/]*%.txt$` can never match. A
leading `/` is what makes a pattern absolute. The `filewatchflat` test
could not catch this: it sends the RelativePattern OBJECT form, so it
constrains the object arm, never the string arm the regression lived in
--- the framing's own F1 finding, repeating inside the lane that named
it.
P2 --- `scan_tree` awaits `read_dir` once per directory, so the watcher
coroutine sits suspended for most of a tick with `_sleep` already
cleared. A cancel arriving there sets `cancelled` and has no sleep to
interrupt, and the resumed scan ran on to `did_change_watched_files`:
one stale batch under the superseded pattern, which is a wrong-pattern
notification the server acts on. Cancellation and liveness are rechecked
after the scan.
Both tests are mutation-checked and each bite fails only its own defect.
Reverting P1 fails the bare-string test alone --- the absolute test
still passes, so the two readings are independent. Deleting P2's recheck
reproduces the defect verbatim: `.received = "1 file:///…/foo.txt"`,
a batch from a watcher that was already cancelled.
P2's witness needs a seam. The race is a cancel landing during one of
the scan's suspensions, which no arrangement of real timing produces on
demand --- the same situation, and the same device, as `git.lua`'s
`_deliver_status`. `pmacs.lsp._after_scan_for_tests` is nil in
production and is handed the SCAN RESULT deliberately: a test that
cancels on any other scan passes with the recheck deleted, because the
loop would break at the post-sleep check and emit nothing anyway.
Gates: 9/9 green.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Implements D1 and D2 from docs/lsp-file-watcher-framing.md (revision 1,
approved 2026-08-10). The user ruled that the walking survives this
lane; D3 gets its own framing.
D1. resolve_watcher now returns (base, pattern, form) and the watch
record carries the form. Per LSP, a plain-string glob matches the
file's ABSOLUTE path while a RelativePattern's pattern is relative to
its base --- and resolve_watcher discarded the distinction, so every
downstream consumer matched relatively. Real servers send absolute
globs: rust-analyzer was never told about any file change (all six of
its globs absolute), and gopls saw go.mod but never a .go edit. The
match subject is chosen in start_file_watcher --- form "absolute"
matches base .. "/" .. rel, form "relative" matches rel unchanged.
scan_tree still walks in relative terms; only the string handed to the
matcher changes.
D2. register_file_watchers now cancels the outgoing record list before
file_watchers[skey][reg.id] = recs drops the only reference to it. The
cancel loop is factored into cancel_watch_records, shared with
unregister_file_watchers, so the two paths cannot diverge.
rust-analyzer registers the same id twice with no unregister between
--- previously 12 concurrent pollers, 6 permanently uncancellable.
Verification, per the framing's plan. Three new fake-LSP modes and
tests beside m4_24, each mutation-tested against the defect it names:
- filewatchabs registers a plain-string absolute glob whose relative
reading matches nothing. Red before D1 (reverting the match subject
fails exactly this test), green after.
- filewatchflat registers a RelativePattern without a leading **/
(*.txt at the base) --- F2's guard. Matching every form absolutely
fails exactly this test, so the obvious wrong fix cannot land green.
It also pins that a base-level pattern does not match into
subdirectories.
- filewatchrereg registers the same id twice (rust-analyzer's shape).
The witness is observable polling, not table shape: f.old exists on
disk before either .new event lands, so a leaked watcher at the same
250ms cadence reports it before the second positive. Reverting D2
fails exactly this test, the leaked .old event visible in .received.
m4_24 stayed green under all three mutations --- the framing's F1
finding (the existing test is insensitive to D1 in both directions),
confirmed rather than assumed. It is kept unchanged.
The framing doc records the approval and the answered ruling; the
active-work lane moves to IMPLEMENTED with the verification results.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Framing and lane at the branch's first commit, so the document is
portable while it is reviewed. The GUI arc framing spent two review
rounds as an untracked file in one worktree; that is the lesson being
applied, not a preference.
Revision 1 is a DRAFT and no implementation may start from it.
Scope is D1 and D2, the two bug-shaped defects. Every claim in the
framing was read or executed against `0e4c58d` rather than carried from
the issue --- including re-running the tree's own `expand_braces` /
`glob_one_to_pattern` / `glob_matcher` under LuaJIT, which reproduces
the issue's glob table exactly, compiled patterns included.
#232 is NOT at fault and nothing about it should be reverted. The
activity indicator renders real in-flight jobs; what changed is
visibility, not behaviour, and the watcher has polled since 1c25730 in
May. Quieting the indicator would delete the instrument that found this.
Two findings the issue does not carry, both of which change the fix:
The existing test cannot discriminate this fix IN EITHER DIRECTION. The
fake LSP registers `**/*.txt`, which compiles to `^.-[^/]*%.txt$`, and
`.-` spans `/` --- so it matches relative and absolute subjects alike
and `m4_24` passes whether D1 is fixed or broken. The issue calls the
tested and exercised paths disjoint; the sharper statement is that the
one existing test is INSENSITIVE.
And "match the absolute path" alone would break `RelativePattern`:
measured, `*.txt` matches `a.txt` but not `/base/a.txt`.
`resolve_watcher` returns `(base, pattern)` and discards which form it
came from, so its CONTRACT has to change, not just the match subject. A
fix that misses this trades six broken rust-analyzer globs for every
RelativePattern that does not begin `**/`. The verification plan
includes a test that fails against exactly that wrong fix.
The framing also records what this lane does NOT fix, so the report is
not mistaken for closed: neither D1 nor D2 stops the walking, because
`walk` recurses unconditionally and `matches` gates only recording. The
modeline will keep flipping at roughly half the rate. Whether that meets
the acceptance bar is an open ruling for the user, stated as one rather
than assumed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Levi Neuwirth