Revision 8 refuses, inside a "panel" commit_to, the mutations that
would make its relaxed preflight wrong. A nested commit_to REPLACED
the enclosing contract with its own and restored it afterwards, so
the outer restriction went out of force for the whole inner body:
commit_to(outer, function() -- "panel", relaxed preflight
commit_to(inner, function() -- "document", MASKS the outer
set_params(panel(), { dedicated = true }) -- ...and succeeds
end)
display(result, { side = "bottom" }) -- ...which now FALLS BACK
end, "panel")
Every step is legal on its own, and the outer commit then overwrote
a newer document buffer --- the P1a failure the lane exists to
remove, reached through one extra call.
What this invalidated, precisely: NOT the enumeration of dedication
write sites. Every site in it is real and still guarded. What was
wrong was the claim that the guard was in force for the whole outer
body. So the enumeration is inherited and qualified, not redone.
Contracts now COMPOSE rather than replace. The core holds a stack;
ScopedFrontendGuard pushes on entry and truncates back to its own
depth on every exit path; panel_commit_dedication_refusal consults
every contract in force rather than the innermost. The strictest
active restriction wins. Matching stays per frontend --- a nested
commit for a different frontend may dedicate its own side slot,
which cannot change where this frontend's side request lands.
Nesting itself is NOT forbidden, which was the other candidate fix.
It closes the hole by prohibiting a construction no rule objects to:
commit_to is public Lua API for saying where a continuation's result
belongs, and a body committing to a second destination (a diff
beside a status panel) is where #227's adoption is heading. Only the
restriction needed preserving. Detecting the dedication when the
outer commit resumed was not available either --- that is a late
refusal, which is what revision 7 was rejected for.
Two pins, and they are a pair rather than one test written twice:
* a_nested_commit_cannot_mask_an_outer_panel_restriction drives the
same four write-site rows through a nested, entirely valid
"document" commit, and asserts the attempt is refused, the slot is
still undedicated, and the outer commit's destination is intact.
* an_ordinary_nested_commit_still_runs_and_restores_the_outer_restriction
pins that nesting without dedication is accepted, that the
enclosing restriction is back in force once the nested commit
returns, and that outside every commit dedication is ordinary
again.
Mutation-checked: restoring the guard to the innermost contract
(.last(), exactly revision 8's swapped slot) fails only the first of
those. The other 13 pins, journey_acceptance (31), dired_acceptance
(47) and cargo test --lib (1920) all stay green. The ordinary-nesting
pin deliberately survives it --- it exists to fail the other
candidate fix.
Also sweeps the comments left by revision 7, which revision 8
superseded: no fallback_commit_refusal symbol remains, but six doc
sites still described placement-boundary enforcement as the
guarantee (ViewDestination, CommitProfile::Panel, CommitContract,
capture_view_destination, commit_destination_refusal,
panel_placement_can_fall_back), plus two comment blocks in the
commit_to binding and one stale mutation note in the acceptance
suite. Net rustdoc warnings down three.
Framing to revision 9; the active-work lane entry updated in place.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Levi Neuwirth
5f3f38dfd7