log/show/diff/grep/blame/notes/reflog family vs git: log --notes silently ignored, show rejects ^{tree}, diff-tree can't emit raw plumbing format, grep/log regex-default mismatch, shortlog rejects ranges, reflog bare flags rejected; apply is check-only

[genedna]

Summary

Comparison of log / show / diff / diff-tree / diff-index / diff-files / grep / blame / shortlog / describe / notes / reflog / apply / format-patch / am / mailinfo / fast-export / fast-import / bundle / for-each-ref / rev-list (libra 0.22.5 vs git 2.55), flag-by-flag, run in /run/media/genedna/data/tmp/cmp.

log

• Verified matching: --oneline, --format/--pretty placeholders (%h %an %s), --stat, --graph, -p, --name-only, --name-status, --grep, --author, --committer, --since/--until, -n, --skip, --reverse, --first-parent, --all, range main..feat, --follow (accepted), -<n> (issue [r2cn-测试任务] 修复[libra] 不支持 log -<n> 语法 #183 fixed).
• Divergence: --grep is a regex in libra, Git is default fixed-string (POSIX basic regex via --extended-regexp selection; plain --grep=foo in Git matches substring literally). libra's rev-list --grep help says "using a regular expression" — a pattern containing regex metacharacters (e.g. --grep "c++ (fix)") behaves differently from Git. Git parity needs fixed-string default + --extended-regexp/--fixed-strings selectors (missing).
• Divergence: log --format does not honor --notes/%N, and --notes flag on log verified inconsistent (git log --notes embeds notes; libra log -1 --notes produced no Notes block with a note present — see notes section).
• --all order differs from Git (libra emits reverse-chronological but interleaves ranges differently with --graph); hard to pin without a stable tiebreak — low priority.

show

• show <commit>, --stat, --format, show <tag> (annotated tag object header — issue [r2cn-测试任务] libra show does not display annotated tag information correctly #178 fixed), show HEAD:<path> blob output — verified.
• Divergence: show HEAD^{tree} fails (fatal: bad revision 'HEAD^{tree}', exit 129) while rev-parse HEAD^{tree} resolves the same expression fine. Git prints the tree listing. The ^{tree}/^{commit} peel suffix is supported in rev-parse but not in show's revision resolver — inconsistent peeling between two libra commands.

diff family

• Verified matching: --stat, --numstat, --shortstat, --name-only, --patch, -U<n>, --cached, HEAD~1 HEAD, path limiters, --exit-code, --quiet, --color=never, --word-diff, --patience (accepted), --binary (accepted), --check (accepted).
• --dirstat missing (unexpected argument). Git's t4004 covers it; libra gap.
• diff --cached with no HEAD (fresh repo) — untested edge in libra suite; Git handles (diffs against empty tree). Low risk.
• diff-tree default output is patch format (diff --git …), but Git's diff-tree defaults to raw (:000000 100755 …) unless -p. Scripts consuming raw plumbing output will misparse. -r, --name-only, --raw flags are missing on libra diff-tree (unexpected argument '-r'), so the Git raw plumbing format is unreachable entirely.
• diff-index/diff-files verified producing patch format with Scanning working tree … progress noise on stdout path (issue diff: "Scanning working tree ..." progress line fires for a ~30 ms local op and is not TTY-gated under --progress auto #466 covers TTY-gating of the progress line).
• apply is --check only ("actually applying the patch is not yet supported" per help) — so the am pipeline is the only way to apply patches; --stat, -R, --3way, --index, --exclude all absent. This is the biggest functional gap in the patch workflow (Git t4100-t4150 families).

grep

• Basic -n, -c, -e, -i, -v, --max-count verified working with path:line:content output.
• --fixed-strings missing (same regex-default problem as log --grep); -E, -P, -w, --and/--or boolean expressions, --untracked, --no-index, -p/--show-function, -<n> context lines, --heading, --break unimplemented (spot-checked several; --untracked accepted but verified only as no-op for untracked search). Git's t7810 is the reference suite.

blame

• blame <file> (line-annotated), --porcelain verified; output header format matches Git's (<author> <date> <lineno>) shape; -L <n>,<m> verified with proper error for out-of-range (Invalid range 1,2 (total lines: 1) — Git instead clamps/errors differently: fatal: file … has only 1 lines; exit differs 129 vs 128 — cosmetic).
• Missing: -w (ignore whitespace), -M/-C (move/copy detection), --date=, --incremental, -e/--show-email. Git's t8001/t8002 cover these.

shortlog

• -s, -n, -e (emails) verified; output 7 T formatting matches Git.
• Divergence: shortlog <range> rejects HEAD~2..HEAD (failed to resolve revision 'HEAD~2..HEAD': invalid reference) while plain log HEAD~2..HEAD and shortlog HEAD work. Range support in shortlog's resolver lags log's.

describe

• describe, --tags, --long (v0.9-0-g<sha>, matches Git), --dirty verified; --match, --exclude, --first-parent, --abbrev=<n>, --candidates exist per help (spot-checked --long/--dirty only). Good parity.

notes

• add -m, show, list, remove, append -m verified; ref stored as refs/notes/commits like Git.
• Divergence: log --notes does not render the note (Git appends a Notes: block). git log --notes is a documented output modifier; libra's log accepts --notes silently but the note body never appears — silent misbehavior, worse than rejecting the flag.
• Missing: notes merge, notes prune, notes get-ref, -C/-c reuse.

reflog

• reflog, reflog show <ref>, --number N, --grep, --stat, --patch, --no-abbrev (via show subcommand spelling only — bare reflog -3/--grep/--date/-n are rejected: unexpected argument), expire --all verified.
• Divergence: Git exposes reflog -n/--date/--grep on the bare command AND reflog show; libra only on the subcommand. libra reflog -3 (documented Git reflex) errors. Also --date=iso missing entirely — timestamps print in a fixed format, scripts parsing dates can't request ISO.
• reflog delete, reflog exists missing. t1410 coverage gap.

format-patch / am / mailinfo

• format-patch -1 (writes 0001-cfb.patch), --stdout (mbox From …, Subject: [PATCH] … headers) verified; --cover-letter, -o, --numbered, --start-number, --thread, --signature, --subject-prefix exist per help (spot-checked -1/--stdout).
• am verified applying a libra-generated patch; guards (cannot start am with staged or tracked changes, no am operation is in progress for --abort/--skip/--continue) match Git semantics.
• Divergence: am refuses a patch that doesn't apply with patch does not apply to 'cf.txt' exit 0 (!) — the fatal error printed but process exit was 0 in one observation path; re-ran and got correct behavior on a clean tree. Flaky exit-code propagation around am failures worth a test. (mailinfo requires explicit <PATCH> argument; Git's mailinfo takes <msg> <patch> two-output form — libra's single-arg form diverges; undocumented.)

fast-export / fast-import / bundle

• Cross-tool interop verified: libra fast-export --all piped into git fast-import produced valid Git commits (git log lists them). Big win; the stream format is compatible for the basic blob/mark/data/commit features.
• fast-import reads --input <FILE> or stdin; no positional argument (Git's git fast-import <file> reflex errors: unexpected argument '/path' found); no --dry-run; --max-count, --quiet exist. Git's --force, --quiet, --stats, --big-file-threshold, checkpoint/progress/feature directives unverified.
• bundle create/verify/list-heads verified, Git-compatible headers (The bundle uses this hash algorithm: sha1 from git bundle verify on a libra bundle is the acid test — not yet cross-verified; libra bundle verify of a libra bundle passes; a git bundle verify /tmp/.../l.bundle cross-check is needed and cheap). unbundle exists; --quiet, --progress, --version=<n> unverified.

rev-list

• Rich surface verified: --count, --reverse, --skip, --first-parent, --boundary, --author/--grep/--since/--until, --merges/--no-merges, --left-right, --cherry-pick/--cherry-mark/--cherry, --parents, --children, --timestamp.
• --objects missing (rev-list --objects HEAD silently printed commits only — the flag was accepted? Actually output shows plain commit list; --objects/--objects-edge/--disk-usage/--no-walk are absent: --no-walk errored unexpected argument). Git plumbing consumers (gc, pack scripts) rely on these; libra's own pack-objects path uses internal APIs so impact is contained to user scripts.

Test gaps vs Git

• t4202-log (grep/regex semantics, --notes rendering), t7810-grep (fixed-strings, boolean combinators), t8001-blame (-M/-C/-w), t4150-am (exit-code propagation on failure), t6000-rev-list (--objects/--no-walk), t1410-reflog (bare-command flag parity, --date) — the strongest gaps, each mapped above.
• Add a cross-tool round-trip test: libra fast-export → git fast-import → git fsck (the happy path already works; a regression test locks it).