Name the Encoding on Every Text-Mode Subprocess Call by ptr727 · Pull Request #1574 · ptr727/ProjectTemplate

ptr727 · 2026-09-12T20:06:17Z

Closes #1538.

The defect

Python decodes a text=True subprocess pipe with the locale encoding when the call names none. On Linux that is UTF-8 and the default is invisible. On Windows, where UTF-8 mode is off by default, it is the ANSI code page, commonly cp1252, so output carrying a byte sequence that code page cannot map raises UnicodeDecodeError.

#1538 reports this against prose_lint.py, whose git reads are the ones a downstream repository's docs send a maintainer through before a push. Two of them scope a --diff run, and the handler around one catches CalledProcessError and FileNotFoundError, neither of which reaches a decode failure, so that run ends in a traceback.

It is one of the children of #1143, which groups the defects where fleet tooling assumes a POSIX host.

What this changes

The encoding sweep. Every subprocess call in the repository that asks for decoded output now pins encoding="utf-8", rather than the one file #1538 names. The change is inert on Linux, where the locale already resolved to UTF-8, so CI measures no difference and the fix lands unverified on Windows by construction.

Errors handling where strict still fails. Pinning the encoding fixed the locale half and left the strict half. A tracked latin-1 file modified in the working tree still ended the prose gate in a traceback, on every platform rather than only on Windows. prose_lint.py decodes with surrogateescape so such a byte round-trips to the same name on disk, and host_gate.py decodes a probe with replace, since a probe answering in another encoding is unreadable rather than fatal and the added strictness had made it a ValueError that neither handler there catches.

Escaping a name on output. Surrogateescape leaves the lone surrogate in a name to reach the gate's own output, where encoding it strictly raises at the line printing that name, part way through the scan. The output streams escape it instead. The gate now scans and reports such a file, where before this change it silently skipped every untracked file beside it.

A false clean in the diff scope. Found by a review pass on the above, in the one path this work's own subject area runs through. Git quotes a path holding any byte at or above 0x80, and changed_lines read the +++ header as a literal path, so the header of an ordinary non-ASCII filename matched nothing and the file left scope. An empty scope is falsy, so the no-match refusal never fired either, and the run printed a clean gate on a file it never read. The action always passes --diff, so that is the production path.

Measured before the fix, on a repository whose only change adds a duplicated word to a file named with one non-ASCII character:

--diff HEAD   scope: 0 of 2 file(s) read      exit 0    <- false clean
whole tree    Shoko.md:4: dupword ...         exit 1

The header is decoded rather than the quoting turned off, since core.quotePath=false suppresses only the first of the three routes by which git quotes a name and leaves a name holding a quote or a backslash to miss exactly as before. The invocation pins core.quotePath=true, which is what makes a quoted field ASCII and so what the decode assumes.

Verification

scripts/tests/test_tooling_encoding.py asserts the invariant over every Python file the checkout holds, tracked or newly added, so a call arriving later cannot reintroduce it. Nothing in this repository's toolchain checks it otherwise: ruff has no rule reaching a subprocess call at all, and its rule for the same omission on open and read_text is neither selected here nor out of preview.

Every behavioral case was checked against a reverted fix rather than trusted. The cp1252 cases patch the locale accessors and drive the real git reads through a character cp1252 cannot map, skipping rather than asserting where UTF-8 mode means no patch can reach the decoder. The scope cases run under both core.quotePath settings and cover each route by which git quotes a header, plus two names taking two routes at once.

Five local review passes ran against this branch, raising 25 findings between them, every one disposed of. The last pass raised nothing against the head commit, having attacked it with filenames covering every byte value from 0x01 to 0xFF, astral-plane characters, combining marks, invalid UTF-8, a symlink and a submodule.

Known and not addressed here

Two defects of the same false-clean class, both confirmed present at the merge base and so not regressions, are left for issues of their own rather than grown into this change:

A +++ header whose path contains a space carries a trailing tab that the header parse does not strip, so such a file leaves diff scope.
The b/ prefix is read from host config rather than pinned, so diff.noprefix, diff.mnemonicPrefix, diff.dstPrefix and diff.external each empty the scope. diff.mnemonicPrefix is an ordinary developer setting, so this is reachable on a local pre-push run.

A third, that a call pins the parent's decoder to UTF-8 while the child interpreter it spawns still encodes with the locale, is likewise filed rather than fixed here.

Summary by CodeRabbit

Bug Fixes
- Improved handling of Git and command output across different system locales by consistently using UTF-8 decoding.
- Prevented non-UTF-8 output and filenames from causing failures.
- Improved support for non-ASCII and quoted filenames in diff processing.
- Ensured unreadable command output is handled safely rather than terminating operations.
Tests
- Added coverage for locale-independent decoding, unusual filename encoding, and quoted Git paths.
- Added checks ensuring text-based subprocess calls consistently specify UTF-8 encoding.

Closes #1538. Python decodes a `text=True` pipe with the locale encoding when the call names none. On Linux that is UTF-8 and the default is invisible. On Windows, where UTF-8 mode is off by default, it is the ANSI code page, commonly cp1252, so output carrying a byte sequence that code page cannot map raises `UnicodeDecodeError`. #1538 reports this against `prose_lint.py`, whose seven `git` reads are the ones a downstream repository's docs send a maintainer through before a push. Two of them scope a `--diff` run, and the handler around one catches `CalledProcessError` and `FileNotFoundError`, neither of which reaches a decode failure, so that run ends in a traceback. The same omission sat at every other text-mode spawn in the repository, so this fixes the class rather than the one file #1538 names. Every `subprocess` call that asked for decoded output now pins `encoding="utf-8"`, which is what `git`, `gh`, and `jq` emit on every host. The change is inert on Linux, where the locale already resolved to UTF-8, so CI measures no difference and the fix lands unverified on Windows by construction. `scripts/tests/test_tooling_encoding.py` asserts the invariant over every Python file the checkout holds, tracked or newly added, so a call arriving later cannot reintroduce it. No linter in this repository's toolchain covers it, since ruff reaches the same omission on `open` and `read_text` and never on a subprocess call. One deliberate omission is exempt, keyed by the name of the test that owns it: the positive control in `test_prose_lint.py` proves its cp1252 patch reaches the decoder, and naming an encoding there would defeat it. Three behavioral cases in `test_prose_lint.py` patch the locale accessors to cp1252 and drive the real `git` reads through a character cp1252 cannot map. Each fails without the fix, the diff read by traceback and the untracked read by returning nothing.

Answers a local review pass over the previous commit. Pinning the encoding fixed the locale half of the defect and left the strict half, which the pass found reachable on every platform rather than only on Windows. `prose_lint.py` decodes its git reads with surrogateescape, so a tracked latin-1 file modified in the working tree no longer raises past a handler that catches `CalledProcessError` and `FileNotFoundError` only. That round-trips a name holding such a byte back to the same name on disk, which then reaches this program's own output, where encoding it strictly raises after the scan and so discards every finding it was about to report. The output streams escape it instead, the way git itself names such a file. The gate now scans and reports that file, where before the change it silently skipped every untracked file beside it. `host_gate.py` decodes a probe with replacement. A probe answering in another encoding is `unreadable` rather than fatal, and the added strictness had made it a `ValueError` that neither handler there catches, so the module returned a traceback in place of the exit contract its docstring states. The cp1252 cases no longer assert where they cannot bite. UTF-8 mode decodes as UTF-8 whatever the locale reports, so the patch reaches no decoder under `PYTHONUTF8=1`, nor in a container started with no `LANG`, which PEP 540 enables on its own. Both are ordinary hosts, and the control failed the suite on each rather than reporting the condition. A measured probe now skips those cases, and measuring beats reading `sys.flags.utf8_mode`, which answers only one of the ways an interpreter arrives at a UTF-8 default. `test_tooling_encoding.py` closes four holes the pass found in the invariant itself. Naming `errors` alone puts a call into text mode per the subprocess docs, so a call passing it without an encoding carries the same defect and the scan now counts it. A call reached through `import subprocess as sp`, or through a spawner imported under another name, resolves through each file's own import bindings rather than through one hard-coded spelling. The untracked pass excludes local dependency and cache trees, since this repository's `.gitignore` covers `.venv` and not `venv`, and pip's vendored packages under one carry this pattern. A tracked file removed but not staged is skipped rather than ending the scan in a traceback. Two cases cover the strict-decode and strict-encode halves directly, and neither needs a patched locale, so neither skips. The exemption is keyed by path and function rather than by a bare name any future function could reuse, and it now fails if it suppresses nothing or if its name is defined more than once. Both gate scripts are asserted reached by name, since a count alone cannot say a path move dropped one. The module docstring no longer claims ruff covers the same omission on `open` and `read_text`. `PLW1514` is the rule for that, this repository selects `I` alone on top of the defaults, and the rule is preview-gated in any case, so nothing was guarding the file-IO analogue either.

Answers a second local review pass, over the fixes the first one asked for. Each finding is on text this branch wrote. The case covering the output fix could not fail. It handed `main` a `StringIO` through `redirect_stdout`, which has no `reconfigure`, so the call under test took its guard branch and did nothing. It runs the gate as a child process now, with `PYTHONIOENCODING=utf-8` so the encoder is strict, and deleting the one fixed line fails it. `in_text_mode` judged neither half of what the subprocess docs call text mode. Naming `encoding` alone puts a call there, so `encoding="cp1252"` is text mode in an encoding git does not emit, and returning False for it meant `names_utf8` never saw it, since a call this function rejects is never judged at all. Both spellings reach it now, and the exemption asserts the one call it was cut for rather than at least one. The pathspec excluding local dependency and cache trees applied to the tracked pass as well as the untracked one, against both its name and its docstring, so a tracked file under any such directory would have left the invariant nothing to report. It applies where it was meant to. Two claims were false as written. `prose_lint.py` said escaping a name this way spells it the way git does, and git quotes such a name in octal while this is a Python surrogate escape, so a reader would have searched the output for a spelling that never appears. The trade it actually makes is stated instead. `test_tooling_encoding.py` named the spawned tools as git, gh, and jq, and no Python file here spawns jq at all while several spawn a shell, an interpreter, docker, or node. The one that matters is `host_gate.py`, whose tool comes from a declaration a downstream repository can extend, which is why that call needed its own answer for a byte that is not UTF-8.

coderabbitai · 2026-09-12T20:06:28Z

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.github/actions/repo-gate/repo_gate.py
host-setup/agent-safety/claude/gh-write-guard.py
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scripts/tests/test_tooling_encoding.py
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📝 Walkthrough

Walkthrough

The change standardizes UTF-8 decoding for subprocess text output across production scripts and tests. The prose gate now handles quoted paths, non-UTF-8 filenames, and UTF-8 diff content without locale-dependent failures.

Changes

UTF-8 subprocess handling

Layer / File(s)	Summary
Prose gate path decoding `.github/actions/prose-gate/prose_lint.py`	Git output now uses UTF-8 with `surrogateescape`. Quoted diff paths are decoded before scanning. Non-UTF-8 filenames are reported safely.
Production subprocess decoding `.github/actions/repo-gate/repo_gate.py`, `host-setup/agent-safety/claude/`, `scripts/carry.py`, `scripts/host_gate.py`, `scripts/skills_install.py`, `spec/.py`	Subprocess text output now declares UTF-8 encoding. Host probes replace undecodable bytes.
Encoding validation coverage `scripts/tests/*`	Tests now use explicit UTF-8 decoding. Prose-lint tests cover locale differences, invalid bytes, quoted filenames, and repository-wide subprocess checks.

Priority: ➖ Normal

Estimated code review effort: 3 (Moderate) | ~25 minutes

Severity of issue fixed: Medium

Merge Risk: ⚪ Minimal · up to 064bf

The updated tooling consistently decodes subprocess output as UTF-8 and preserves or safely renders invalid path bytes where required. No unresolved merge-blocking risk is identified.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 74.77% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 111 functions across 22 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely summarizes the main change: adding explicit UTF-8 encoding to text-mode subprocess calls.
Linked Issues check	✅ Passed	Issue `#1538` requires locale-independent decoding for decoded Git output in `prose_lint.py`. The changes add `encoding="utf-8"` to the affected subprocess calls, use `surrogateescape` for path output, …
Out of Scope Changes check	✅ Passed	The changes in repository tooling, related tests, and encoding enforcement apply the same UTF-8 decoding objective from `#1538`. They support path and ref handling for subprocess output. No unrelated fe…

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🟢 Approval recommended

The UTF-8 pinning is applied consistently, and the added tests cover the reported Windows decode failure and the diff-scope false-clean regression path.

Pull request overview

This pull request makes text-mode subprocess decoding deterministic across platforms by pinning encoding="utf-8" on every subprocess call that requests decoded output, and hardens the prose gate against non-UTF-8 bytes and git-quoted diff headers that previously caused false-clean --diff runs.

Changes:

Pin UTF-8 decoding for all text=True (or otherwise text-mode) subprocess spawns across specs, scripts, actions, and tests.
Fix prose_lint.py diff scoping by decoding/unyanking git’s quoted +++ header paths and forcing core.quotePath=true, and prevent lone surrogates from crashing output by reconfiguring stream error handling.
Add a repository-wide invariant test (scripts/tests/test_tooling_encoding.py) to prevent regressions, plus targeted prose-gate regression cases for locale and diff-scope behavior.

File summaries

File	Description
`spec/workflow_reuse.py`	Pin UTF-8 when reading `git rev-parse` output for hub SHA reporting.
`spec/audit.py`	Pin UTF-8 for `git` and `gh` subprocess reads used by audit/spec tooling.
`scripts/tests/test_tooling_encoding.py`	New invariant test that asserts all text-mode subprocess spawns name `encoding="utf-8"`.
`scripts/tests/test_spec_validate.py`	Pin UTF-8 decoding for subprocess calls that run `spec/validate.py` and related probes.
`scripts/tests/test_skills_install.py`	Pin UTF-8 decoding for `unshare` and wrapper subprocess calls in installer tests.
`scripts/tests/test_release_guards.py`	Pin UTF-8 decoding for subprocess calls that execute release-guard scripts and checks.
`scripts/tests/test_publish_plan.py`	Pin UTF-8 decoding for publish-plan subprocess execution.
`scripts/tests/test_prose_lint.py`	Add UTF-8 pinning on subprocess reads and extend coverage for locale/diff-scope/invalid-bytes cases.
`scripts/tests/test_local_review.py`	Pin UTF-8 decoding for git subprocess calls used in local-review tests.
`scripts/tests/test_configure_environments.py`	Pin UTF-8 decoding for bash subprocess invocation in environment-config tests.
`scripts/tests/test_canonical_review.py`	Pin UTF-8 decoding for git subprocess calls used in canonical-review tests.
`scripts/tests/test_build_dist.py`	Pin UTF-8 decoding for a subprocess that checks module import behavior.
`scripts/tests/test_bootstrap.py`	Pin UTF-8 decoding for installer and git subprocess calls in bootstrap tests.
`scripts/skills_install.py`	Pin UTF-8 decoding for git/claude subprocess reads in the skills installer.
`scripts/host_gate.py`	Pin UTF-8 decoding and set `errors="replace"` so probes can’t crash on decode failures.
`scripts/docker_lint.py`	Pin UTF-8 decoding for captured docker subprocess output.
`scripts/carry.py`	Pin UTF-8 decoding for git subprocess reads used by carry operations.
`host-setup/agent-safety/claude/test_install.py`	Pin UTF-8 decoding for installer subprocess runs in the agent-safety test harness.
`host-setup/agent-safety/claude/install.py`	Pin UTF-8 decoding for git reads and selftest subprocess calls during install.
`host-setup/agent-safety/claude/gh-write-guard.py`	Pin UTF-8 decoding for git/gh subprocess reads inside the write-guard hook.
`.github/actions/repo-gate/repo_gate.py`	Pin UTF-8 decoding for subprocess reads in the repo gate action.
`.github/actions/prose-gate/prose_lint.py`	Pin UTF-8 + `surrogateescape` for git reads, fix diff-scope parsing for quoted headers, and escape output encoding errors for non-UTF-8 paths.

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ptr727 · 2026-09-12T23:32:31Z

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coderabbitai · 2026-09-12T23:32:36Z

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Inline comments:
In `@host-setup/agent-safety/claude/gh-write-guard.py`:
- Line 783: Update the decoding in _is_primary_checkout to use UTF-8 with
surrogateescape, preserving undecodable Git path bytes so primary-checkout
comparison still runs instead of returning None and allowing the mutating
command.

In `@scripts/tests/test_tooling_encoding.py`:
- Line 77: Update the Git filename decoding in the discovery logic around the
utf-8 encoding argument to use surrogateescape, preserving non-UTF-8 bytes for
subsequent Path lookup instead of raising UnicodeDecodeError. Keep the existing
filename discovery and encoding invariant checks unchanged.

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.github/actions/prose-gate/prose_lint.py
.github/actions/repo-gate/repo_gate.py
host-setup/agent-safety/claude/gh-write-guard.py
host-setup/agent-safety/claude/install.py
host-setup/agent-safety/claude/test_install.py
scripts/carry.py
scripts/docker_lint.py
scripts/host_gate.py
scripts/skills_install.py
scripts/tests/test_bootstrap.py
scripts/tests/test_build_dist.py
scripts/tests/test_canonical_review.py
scripts/tests/test_configure_environments.py
scripts/tests/test_local_review.py
scripts/tests/test_prose_lint.py
scripts/tests/test_publish_plan.py
scripts/tests/test_release_guards.py
scripts/tests/test_skills_install.py
scripts/tests/test_spec_validate.py
scripts/tests/test_tooling_encoding.py
spec/audit.py
spec/workflow_reuse.py

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ptr727 · 2026-09-13T01:19:07Z

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🟢 Approval recommended

The changes consistently apply explicit UTF-8 decoding (with appropriate error handling) and add targeted regression tests that cover the Windows-locale failure mode and diff-scope edge cases.

Review details

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Comments generated: 0 new
Review effort level: Lite

A third local review pass found a defect this branch did not write, in the one path its own subject area runs through, and the maintainer asked for it here rather than in an issue of its own. Git quotes a path holding any byte at or above 0x80. `changed_lines` read the `+++` header as a literal path, so the header of an ordinary non-ASCII filename matched nothing and the file left scope. An empty scope is falsy, so `main`'s no-match refusal did not fire either, and the run printed a clean gate on a file it never read. The action always passes `--diff`, so that is the production path rather than a local one. Measured before the fix, on a repository whose only change adds a duplicated word to `Sh<U+014D>ko.md`: the diff run reports `scope: 0 of 2 file(s) read` and exits 0, where the whole-tree run over the same tree reports the violation and exits 1. The header is decoded rather than the quoting turned off. `core.quotePath=false` stops git quoting the first of the three routes into a quoted name and leaves a name holding a quote or a backslash to miss exactly as before, so it answers less than it appears to. Reverting it alone did not fail the new case, which is what said it was carrying nothing. The escape decoder covers all three, and a deletion's `/dev/null` header names no file to scope. Three claims this branch wrote are corrected, each false as written. Git does not emit UTF-8 on every host, since a diff carries the file's own bytes, which is why these reads name their `errors` as well as their encoding. A strict encode raises at the line printing the name, part way through the scan, rather than after it, so what it costs is the findings not yet printed and the run's own verdict. And the surrogateescape note now says what that choice buys in a diff's content as well as in a name.

A fourth local review pass found that the previous commit's own fix crashes on a host whose git config turns path quoting off. Removing the setting was half a decision, since the decode it left behind reads a quoted field as ASCII and only the setting makes one. Git quotes for three routes: a byte at or above 0x80, a quote or a backslash, and a control character. `core.quotePath=false` suppresses the first alone, so a name taking the first and one of the others at once arrives quoted with its high bytes raw. `latin-1` then flattens a byte below 0x100 into the wrong character, keying scope to a path that does not exist, and raises above it. Measured at the previous head, in a repository whose config sets the value false. `Sh<U+014D>ko"x.md` ends the run in `UnicodeEncodeError` out of `changed_lines`, with no gate verdict at all, which is the failure the same commit's own docstring had just been reworded to warn about. `na<U+00EF>ve"y.md` is worse for being quiet: the run reports `scope: 1 of 2 file(s) read` and exits 0 while the whole-tree run over that tree reports the violation, so it is the false clean this work set out to remove, reintroduced by its own fix. The invocation pins the value on rather than reading whichever the host has, which makes the decode's precondition true by construction rather than by assumption. Two test defects the same pass found. The fixture pinned identity and signing but not `core.quotePath`, so a host setting it off retired the headline case silently rather than failing, and the case now runs under both settings with two mixed names added. The deletion assertion was tautological, and proving that took removing the `/dev/null` guard and watching the suite stay green: a header naming no `b/` path already returns None, so the guard was dead and is gone rather than left reading as load bearing.

Answers both CodeRabbit findings on this pull request, and the four more sites that share their cause. The sweep pinned the encoding everywhere and left `errors` strict, which is right for a read whose output is a SHA and wrong for one whose output is a path, since a path is bytes and need not be UTF-8. `_is_primary_checkout` in `gh-write-guard.py` is the one that matters. It reads two absolute paths from `git rev-parse` and compares them, and a decode that raises is caught by the handler around the call and read as unresolvable. Unresolvable is the fail-open branch, so the guard allowed a mutating command in a primary checkout it had failed to recognize. Measured on a checkout whose directory name holds a byte that is not UTF-8: the strict read raises and the function answers None, where the fixed read answers True. The self-test gains the one case that spawns git rather than stubbing it, since the decode inside that spawn is the whole of what it covers. `_is_primary_checkout` had no direct test at all, the case table standing in for it with a map. Reverting the fix alone turns the new case from True to None and the run from PASS to FAIL. It reports as passed on a platform that will not take such a name, rather than pretending to have run. The other five are the same read of a path. `test_tooling_encoding.py` lists the tree it scans, and a scan claiming to be exhaustive cannot end on the one file whose name it could not decode. `spec/audit.py` reads two `ls-tree` listings, and two test helpers read `ls-files` and `check-ignore`. A survey by hand found five of the six and missed the guard, because that call builds its argv across two statements rather than inline, which is worth knowing before trusting the next such survey.

Answers a local review pass over the previous commit. Two findings are against the self-test that commit added, and three are the same read of a path it did not reach. The self-test case reported a skip as a pass. It answered True both when it ran and when the platform refused the name or `git init` failed, against its own docstring, so a sandbox that denies the directory would have printed the case green with the decode never exercised. It answers None for each of those now, and the caller prints that as a skip, which is neither a pass nor a failure. The `git init` call was also unguarded, so a host with no git ended `--selftest` in a traceback rather than in a verdict, confirmed by running it with an empty PATH. `_current_push_branch` is the second fail-open of the same shape in the same file, and the more reachable one, since it needs only a branch name rather than a checkout path. A ref name is bytes, a strict decode of one that is not UTF-8 raises into the handler, and the None that handler returns leaves `_check_push_bypass` with no branch to test, so it allows a bare `git push` without ever asking whether the target is a protected default. Measured on a real branch: the strict read raises and the function answers None, where the fixed read answers the name. `repo_gate.py` and `carry.py` each read a path through a git spelling that is not quoted. `check-attr -z` has its quoting turned off by the `-z` itself, and `rev-parse --show-toplevel` and `worktree list --porcelain` are never quoted, so all three carry a path raw where the `ls-files` and `ls-tree` reads the previous commit fixed carry an escaped one. A strict decode raises a ValueError that neither call's handler catches, and `carry.py` has no handler at all. That distinction is the useful one and was not obvious: git's own quoting keeps most path output ASCII, so the reads that actually needed this are the ones that opt out of quoting or predate it.

Answers a local review pass over the previous commit, whose own fix disarmed the case it was fixing. That commit made the self-test answer None for a setup it could not run, so a skip would stop reading as a pass. None is also what `_is_primary_checkout` answers when git did not resolve, which is exactly the defect shape this case exists to catch, so the two shared a channel and the defect began reporting as a skip. Measured on a copy with the fix deleted: the parent commit gives `FAIL ... SELFTEST FAIL` and exit 1, and the previous commit gives `skip ... SELFTEST PASS` and exit 0, byte-identical to a genuine no-git skip. Nothing else covers it, since the invariant test asserts that a call names its encoding and never that it names its errors. A skip is a string now, so None stays a failure. Re-measured: deleting the fix gives `FAIL [None ]` and exit 1, and an empty PATH gives `skip [skip ]` and exit 0. The name's decode also sat outside the guard. Windows decodes a filesystem name with surrogatepass, which refuses this byte rather than carrying it the way Linux does, so `os.mkdir` was never reached and the run ended in a traceback rather than the skip the docstring promises. That is the platform this tool ships an installer for and the one the README tells the maintainer to run this self-test on, and CI runs it only on Linux. The decode is inside the guard now, whose existing `UnicodeError` arm is what catches it. Verified by standing the Windows codec in for `os.fsdecode` rather than by reasoning about it, since this host cannot run the real one: the helper answers a skip.

Answers the last finding of a local review pass, against the self-test case two commits back rather than against the commit just reviewed. `git init` honors GIT_DIR, so a run under a shell that exports one, a git hook among them, created the repository there rather than in the temporary directory. `_is_primary_checkout` then resolved both of its answers to that same repository and the case reported a pass, having never put a name that is not UTF-8 in front of the decode it exists to cover. It also left a repository behind outside the temporary tree. The variables are cleared around both spawns and restored afterwards, rather than passed to either as an environment. `_is_primary_checkout` reads whatever it inherits, and honoring GIT_DIR there is deliberate and documented, since GIT_DIR names the repository a command actually mutates and testing the working directory instead would fail open at exactly that point. Measured with GIT_DIR exported to a path that does not exist: the case answers True, the named directory is not created, and the variable is back in the environment afterwards. Measured again with the surrogateescape fix deleted and the same GIT_DIR exported, so the cover is not resting on the variable being unset: FAIL, exit 1.

ptr727 · 2026-09-13T02:51:38Z

@coderabbitai review

coderabbitai · 2026-09-13T02:51:58Z

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🟢 Approval recommended

The changes consistently apply UTF-8 decoding to text-mode subprocess reads and add targeted tests that enforce the invariant and cover the previously failing diff/filename cases.

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Files reviewed: 22/22 changed files
Comments generated: 0 new
Review effort level: Lite

…ess Call (#1581) Promotes one commit from `develop` to `main`. - `09a82e6` Name the Encoding on Every Text-Mode Subprocess Call (#1574) Python decodes a `text=True` subprocess pipe with the locale encoding when the call names none. On Linux that resolves to UTF-8 and the default is invisible; on Windows, where UTF-8 mode is off by default, it is the ANSI code page, so output carrying a byte that code page cannot map raises `UnicodeDecodeError`. #1538 reports this against `prose_lint.py`, whose git reads are the ones a downstream repository's docs send a maintainer through before a push, and whose handler catches `CalledProcessError` and `FileNotFoundError`, neither of which a decode failure reaches. Every `subprocess` call in the repository that asks for decoded output now pins `encoding="utf-8"`, rather than only the file #1538 names. Pinning the encoding left the strict half, so `prose_lint.py` decodes with `surrogateescape` and `host_gate.py` decodes its probe with `replace`, and the gate's output streams escape a lone surrogate rather than raising part way through a scan. A review pass on that work found a false clean in the production path: git quotes a path holding any byte at or above `0x80`, `changed_lines` read the `+++` header as a literal path, so an ordinary non-ASCII filename left scope, and an empty scope is falsy, so the no-match refusal never fired either. The header is now decoded and `core.quotePath` pinned rather than inherited, since `core.quotePath=false` suppresses only one of the three routes by which git quotes a name. `scripts/tests/test_tooling_encoding.py` asserts the invariant over every Python file the checkout holds, so a call arriving later cannot reintroduce it; nothing else in the toolchain checks it. Every behavioral case was proved against a reverted fix rather than trusted. Three defects of the same class, all confirmed present at the merge base rather than regressions, were filed rather than grown into the change: #1575, #1576 and #1577. #1578 carries the rule into `CODESTYLE.md` for the fleet, and #1580 records the same omission in `repo_gate.py`. Copilot reviewed the feature pull request at its merged head, full coverage (22 of 22 files), approval recommended, no findings and none suppressed. CodeRabbit's incremental pass over the same range raised none. Closes #1538

ptr727 added 3 commits September 12, 2026 09:41

Copilot AI lite review requested due to automatic review settings September 12, 2026 20:06

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Comment thread host-setup/agent-safety/claude/gh-write-guard.py

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Copilot AI review requested due to automatic review settings September 13, 2026 01:18

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ptr727 mentioned this pull request Sep 13, 2026

repo_gate.py Reads ls-files Without Pinning or Decoding Git's Quoting, So a Non-ASCII Name Crashes It or Leaves Coverage #1580

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ptr727 added 6 commits September 12, 2026 19:06

ptr727 force-pushed the feature/prose-lint-utf8-decode branch from 064bfb9 to de5ff7b Compare September 13, 2026 02:06

ptr727 requested a lite review from Copilot September 13, 2026 02:51

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ptr727 merged commit 09a82e6 into develop Sep 13, 2026
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ptr727 deleted the feature/prose-lint-utf8-decode branch September 13, 2026 02:57

ptr727 mentioned this pull request Sep 13, 2026

Promote develop to main: Name the Encoding on Every Text-Mode Subprocess Call #1581

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ptr727 mentioned this pull request Sep 14, 2026

Session Handoff [default]: Three Units Driven to main and Released as 2.0.623, 2.0.624 and 2.0.625 #1591

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