Review follow-up on F-005. The basename-collision check only ran in
ResolverState::into_plan, which covers fresh resolves and UpdateOne — but
UpdatePolicy::Frozen returns Lockfile::to_resolve_plan(...) directly,
building a ResolvePlan without the check. A pre-existing or hand-edited
lockfile containing two distinct packages that share an install basename
(e.g. owner/magit and other/magit) would produce one plan and install both
to <root>/<basename>, silently colliding.
Make find_basename_collision (and its message helper) pub(crate) and apply
it in Lockfile::to_resolve_plan too — up front, before any fetch, so a
colliding lockfile fails fast via a new LockfileError::BasenameCollision
(surfaced through the Frozen path as ResolveError::Lockfile). Both
plan-construction sites now reject; to_resolve_plan is pub and has direct
callers, so guarding the method (not just the resolve_with_policy branch)
covers them all.
New unit test builds a two-entry colliding lockfile and asserts
to_resolve_plan rejects it before touching the fetcher.
Validated: fmt clean; clippy --all-targets clean under both Lua flavors;
1437 lib tests pass (incl. the new frozen-path test).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014TXbAwk27agwhrNNrhLi2U
Levi Neuwirth
8472c4d87b