`latex_within_boundary` answered a question about path COMPONENTS with
string arithmetic:
dir:sub(1, #boundary + 1) == boundary .. "/"
With a `/` boundary the needle is `"//"`, which no canonical path
begins with. Every ancestor was therefore judged out of bounds, the
marker walk never examined a single directory, and each chapter of a
thesis got its own root — two texlab processes for one document tree.
The lane's headline behaviour, silently off, with all fourteen shipped
tests still green because every one of them clamps the boundary to its
own tempdir.
Fixed by comparing segments rather than characters, so the root is a
boundary with zero segments — containing everything by construction
instead of by a special case, and tolerating a trailing separator for
free. The same root-is-special trap sat at two other points on the same
path and is closed with it:
* `latex_parent_of` returned nil for a top-level directory, making `/`
the one directory the walk could never examine — the identical bug
from the far end. It now yields `/`, matching `walk_for_marker`'s
`Path::ancestors` on the Rust side, and still terminates because `/`
has no component to strip.
* `latex_root_for` sliced `/paper.tex` to an EMPTY directory, which
canonicalizes to nothing and made the resolver DECLINE — and a
decline is the one path that falls through to `pmacs.project.detect`,
whose walk includes `.git`. A document at the filesystem root now
roots at `/`.
* `latex_marker_in`'s join is guarded for `dir == "/"`, which this
change makes reachable for the first time; the naive form produces
`//name`, the one spelling POSIX leaves implementation-defined.
Two new pins plus a strengthened one, 16 tests:
* `two_chapters_share_one_server_under_a_root_search_boundary` — the
defect end to end through ATTACH, not on the predicate, because the
symptom is two servers rather than a wrong string. Restoring the old
comparison fails exactly this test, with the two-server output.
* `latex_root_walk_stops_at_the_search_boundary` now asserts BOTH
directions. "Stops at the boundary" is also satisfied by a walk that
never runs — which is precisely what a `/` boundary produced — so the
hermeticity property (R8's shape: a stray `latexmkrc` above the
tempdir must stay invisible) is now paired with the walk still
climbing to, and examining, the boundary directory itself.
* `latex_root_for_a_document_at_the_filesystem_root_is_the_root`.
Also corrects `docs/active-work.md`: §3 no longer awaits a revision 3 —
`b5eaf27` IS revision 3 — and the lane entry now records that boundary
handling has been this resolver's interesting part twice, so a reader
weighing whether to trust it knows where to look first.
Gates: ALL GREEN via `./scripts/gate --acceptance lsp_latex_acceptance`.
`/tmp` on this machine is a near-full tmpfs and three grep tests fail
there with `QuotaExceeded`; the green run used
`TMPDIR=/home/jeans/build/pmacs-gate-tmp/lsp-latex`.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Levi Neuwirth
9a1e11c0c8