Beagle SCM

DIFF-010: weave.fold: failed (out full?) — the diff/weave fold buffer overflows without grow-on-full

err: Error: weave.fold: failed (out full?) — the JS weave.fold (WEAVENext, the diff/merge fold binding over the C WEAVE; see be/verbs/patch/patch.js:12) overflows its output buffer ("out full") on a large fold, and the caller does NOT grow-and-retry. be/core/loop.js:128-142 ALREADY does grow-on-"out full" (doubles the cap, replays the held records) — but a DIRECT weave.fold call (the diff:/commit: diff path in be/views/diff/diff.js) lacks that, so it throws. Surfaced live via COMMIT-006's commit: diff-inline on a commit with a large change. Sibling of DIFF-007 (diff outtoks overflow) + the JS-055 grow-on-NOROOM pattern. Method: Issues.

Input

Context

• Live error: err: Error: weave.fold: failed (out full?). weave.fold = WEAVENext (binding over C graf/dog WEAVE); its output buffer fills ("out full" = the binding's NOROOM) on a large diff fold.
• be/core/loop.js:128-142 grows on "out full" (double cap + replay) for the LOOP's records; :142 only grows when the error includes "full". A DIRECT weave.fold call (diff.js / the commit: diff-inline) bypasses that → throws.
• C WEAVE caps: graf/WEAVE.c (SNOROOM/NOROOM ~:324/452/587), dog/WEAVE.c WEAVE_FULL_HUNK_MAX (:1260). The binding surfaces these as "out full".
• Trigger: jab commit:?<sha> (COMMIT-006 diff-inline) / jab diff: on a big diff.

Goals

• A large diff/weave fold does NOT error "out full" — the weave.fold caller grows the output buffer + retries (mirror loop.js:128-142 / JS-055), or sizes to content.
• jab diff: / commit: / patch over a large change render the full diff, no throw.

Constraints

• Prefer grow-on-full + replay (the loop.js / JS-055 pattern) over a bigger fixed cap (a fixed bump just moves the cliff). Reuse loop.js's grow-on-full if shareable.
• Localize ALL direct weave.fold callers (be/views/diff/diff.js + be/verbs/patch/patch.js + any shared weave helper). ABC/JS style. Repro-first (CLAUDE §17).

WIP

Design decisions

• CHOSE a SHARED wrapper be/shared/weave.js: growOnFull(make, op, cap, hint) (generalises loop.js:128-142) + fold/merge builders; diff/patch both reuse it.
• Grow EVERY overflow point, not just the named fold: the WEAVE fold AND the HUNK emit (emitDiff/emitFull) AND the per-record plain/color io.buf all throw "...full".
• Sites found: diff.js diffFile wA/wB folds + emitDiff/emitFull + emitHunks render; patch.js foldCommit fold+merge, mergeApply merge+merged, aliveOf/adjacent-skip alive.
• diff.js's ctx.views is unpopulated in the live loop, so jab diff: returns empty; the fold path is reached via commit:?<sha> (commit.js COMMIT-006, calls diff VIEW).

TODOs

• Repro-first: jab commit:?<sha> on a 2800-line change → weave.fold: failed (out full?), exit 1 (RED). diff.js diffFile fold overflows the fixed 1<<18 WEAVE cap.
• Fix: shared grow-on-full retry (shared/weave.js) at every diff.js/patch.js overflow.
• Test be/test/diff/12-large-fold-grow/run.sh + be/ suite green; small diffs unaffected.

Blockers and bummers

• The be-js-bro-pager "dup-const" seen mid-run was the concurrent BRO-005 log-link worker writing pager.js — transient, GREEN once that landed (4febec96). Only the pre-existing be-js-bro-universal stale xfail stays red; both untouched here.

Outcome

• (LANDED be f3389efa + be/test 374cbae0) Fix: shared be/shared/weave.js grow-on-"out full" retry (growOnFull/fold/merge), used by be/views/diff/diff.js (diffFile folds 94-114, emitHunks render 136-139) + be/verbs/patch/patch.js (foldCommit, mergeApply, aliveOf). weave.fold sites: diff.js:95-96/100-101 (was), patch.js:184/202/171/283.
• Test be/test/diff/12-large-fold-grow/run.sh (RED: out-full+exit1; GREEN: diff renders). be/ suite green bar the two pre-existing bro fails. STOPPED pre-commit.