New S11-S13 in lib/tests/run-doc-shape.sh (+4 assertions, 19→23) +
truncate_last_n() helper (removes exactly N lines from the END of a
committed file — pure removal, 0 added lines, no heading, so the
ADDED-envelope and heading checks at doc-shape.sh:70/78 can't fire
first). Baseline = 40 plain committed lines, then truncated. S11
remove exactly 20 (== default DOC_SHAPE_MAX_REMOVED, `-gt` boundary)
→ within (0). S12 remove 30 → exceeds (1), stderr names the path. S13
DOC_SHAPE_MAX_REMOVED=5 override + 6-line removal → exceeds (1).
Closes J4-08 (WEAK): the REMOVED branch was never driven over
threshold by any existing case (S4 only removes 2 lines) — a
regression here mislabels a large doc deletion MINOR and doc-syncer's
auto-commit flow would swallow it silently (the exact RISK-1 BDR-040's
oracle exists for).
Mutation (lean scratch copy — only doc-shape.sh + run-doc-shape.sh,
not the whole repo/.git): changed `-gt "$DOC_SHAPE_MAX_REMOVED"` to
`-gt 2000` (doc-shape.sh:82). RED: S12 fails both assertions (30
removed no longer exceeds) and S13 fails (the hardcoded literal also
kills the env-override contract — DOC_SHAPE_MAX_REMOVED=5 no longer
has any effect). S11 stays green (20 removed was always within,
mutation-invariant). 3/3 reds land exactly where expected.
GREEN: real repo unmutated, 23/23 passed, shellcheck clean.
(1) lib/doc-shape.sh — deterministic shape oracle re-checks each LLM-classified
MINOR patch before the silent auto-commit; a shape-suspect patch (added heading
/ oversize / new file / non-doc) escalates to the EXISTING SIGNIFICANT gate.
Genuine MINOR still auto-commits (zero friction, BDR-036 preserved). A structural
floor under the LLM call, not a semantic SIGNIFICANT-detector (BDR-040).
(2) lib/doc-commit.sh — guard the commit itself: a rejected git commit (pre-commit
hook / protected branch / signing) now fails loud with exit 5 + empty stdout,
instead of a false "committed" + the previous HEAD's hash + exit 0 that left docs
silently uncommitted (LRN-071, 3rd occurrence of the swallowed-commit pattern
after LRN-066 and LRN-068/BLK-012).
Wired doc-syncer STEP A4 (whole-set escalation: no=revert all, select=keep subset)
+ doc-commit.md (rc-5 consumer row + ACKNOWLEDGMENTS coherence).
TDD RED->GREEN: run-doc-commit.sh 32/32, run-doc-shape.sh 19/19, behavioral C/D.
shellcheck clean. Branch-guard (3) deferred.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01C6bUdvHnajCNzgVQefZowj
Bastien Chanot