The git-diff viewer can now diff the current branch against a base commit-ish
(e.g. main) — review an agent's whole branch from your phone before merging, not
just uncommitted changes. Completes the long-deferred FR-B1.9.
- src/http/diff.ts: getDiff() gains an optional base. Three-layer defense so an
attacker-supplied base never reaches a shell or acts as a git option:
(1) isPlausibleRev() rejects leading '-', '..'/'...' ranges, metachars, control
chars, >250 chars; (2) git rev-parse --verify --quiet --end-of-options
<base>^{commit} — only a resolved 7-64 hex sha is accepted, else empty result;
(3) git diff --no-color <sha>... -- (three-dot = the branch's changes since
divergence, PR-style). execFile, no shell, timeout + maxBuffer bound.
- src/types.ts: additive optional base on DiffResult.
- src/server.ts GET /projects/diff reads ?base (400 on !isPlausibleRev); read-only.
- public/diff.ts: a "compare base" <select> (Working tree + one option per base),
disables Working/Staged tabs in base mode. public/projects.ts derives bases from
the worktree branches ∪ current branch.
Verified: typecheck + build:web clean, 1763 pass (diff tests 87 green). The 1 red
in the plain full run is the pre-existing real-PTY "ring buffer" flake (times out
at default 5s under sandbox load; 27/27 at --test-timeout=30000) — unrelated.
The 'New worktree' form POSTed { repoPath, branch } to /projects/worktree, but
server.ts:706 and the documented contract (FEATURE_WALKAWAY_WORKBENCH FR-B3.1)
read body.path — so every browser worktree-create returned 400 'path and branch
are required' and git worktree add never ran. Send 'path' instead. The existing
worktree-form test had locked in the wrong key (asserted repoPath), which is why
it stayed green while the feature was broken; corrected to assert 'path'.
