## Summary
- Treat PowerShell stop-parsing token forms as unsupported in the
AST-backed command flattener.
- Add focused regressions at the parser layer and Windows command-safety
layer.
## Why
The command-safety parser lowers PowerShell AST elements into argv-like
words. Stop-parsing syntax preserves a native-command argument shape
that this lowering does not model, so these forms should stay on the
conservative unsupported path.
## Validation
- `cargo fmt --manifest-path codex-rs/Cargo.toml --all --check`
- `cargo test --manifest-path codex-rs/Cargo.toml -p
codex-shell-command`
## Why
This is a follow-up to the Windows Git safe-command bypass fix for
BUGB-15601. Git's global `--paginate` / `-p` flags can route output
through a configured pager, so they should not be auto-approved as safe
before the subcommand. At the same time, `-p` after read-only
subcommands like `log`, `diff`, and `show` is the common patch-output
flag, so treating every `-p` as unsafe would make ordinary read-only
inspection commands prompt unnecessarily.
## What Changed
- Split Git option safety matching into explicit global-option and
subcommand-option lists.
- Treat global `git --paginate ...` and `git -p ...` as unsafe.
- Keep post-subcommand patch usage such as `git log -p`, `git diff -p`,
and `git show -p HEAD` safe.
- Keep the pagination coverage with the shared Git safe-command
implementation rather than the Windows wrapper tests.
- Remove the stale `git_global_option_requires_prompt` helper now that
safe-command Git option matching owns the prompt-required lists.
## Testing
- `cargo test -p codex-shell-command`
## Why
BUGB-15601 showed that the Windows safe-command path had drifted from
the generic Git classifier. The Windows-specific Git parser could
classify a PowerShell-wrapped `git` command as safe as soon as it found
a safelisted subcommand, without applying the generic checks for unsafe
subcommand options such as `--output`, `--ext-diff`, `--textconv`,
`--paginate`, or `cat-file --filters`.
The generic classifier already models the Git command boundary and the
read-only argument checks more carefully, so Windows should reuse that
logic instead of maintaining a smaller parallel parser.
## What Changed
- Extracted the existing generic Git classification logic into
`is_safe_git_command`.
- Updated `windows_safe_commands.rs` to call that shared helper for
parsed PowerShell `git` commands.
- Removed the Windows-only Git subcommand safelist, including the
`cat-file` allowance that was part of the reported bypass.
- Added a Windows regression test that keeps PowerShell-wrapped Git
commands with side-effecting options classified unsafe.
- Made the full-path PowerShell test discover the installed PowerShell
executable instead of depending on one hard-coded `pwsh.exe` path.
## Verification
- `cargo test -p codex-shell-command
rejects_git_subcommand_options_with_side_effects`
- `cargo test -p codex-shell-command
git_global_override_flags_are_not_safe`
- `cargo test -p codex-shell-command
windows_powershell_full_path_is_safe -- --nocapture`
Co-authored-by: Codex <codex@openai.com>
## Why
On Windows, Codex runs shell commands through a top-level
`powershell.exe -NoProfile -Command ...` wrapper. `execpolicy` was
matching that wrapper instead of the inner command, so prefix rules like
`["git", "push"]` did not fire for PowerShell-wrapped commands even
though the same normalization already happens for `bash -lc` on Unix.
This change makes the Windows shell wrapper transparent to rule matching
while preserving the existing Windows unmatched-command safelist and
dangerous-command heuristics.
## What changed
- add `parse_powershell_command_plain_commands()` in
`shell-command/src/powershell.rs` to unwrap the top-level PowerShell
`-Command` body with `extract_powershell_command()` and parse it with
the existing PowerShell AST parser
- update `core/src/exec_policy.rs` so `commands_for_exec_policy()`
treats top-level PowerShell wrappers like `bash -lc` and evaluates rules
against the parsed inner commands
- carry a small `ExecPolicyCommandOrigin` through unmatched-command
evaluation and expose `is_safe_powershell_words()` /
`is_dangerous_powershell_words()` so Windows safelist and
dangerous-command checks still work after unwrap
- add Windows-focused tests for wrapped PowerShell prompt/allow matches,
wrapper parsing, and unmatched safe/dangerous inner commands, and
re-enable the end-to-end `execpolicy_blocks_shell_invocation` test on
Windows
## Testing
- `cargo test -p codex-shell-command`
## Why
`//codex-rs/shell-command:shell-command-unit-tests` became a real
bottleneck in the Windows Bazel lane because repeated calls to
`is_safe_command_windows()` were starting a fresh PowerShell parser
process for every `powershell.exe -Command ...` assertion.
PR #16056 was motivated by that same bottleneck, but its test-only
shortcut was the wrong layer to optimize because it weakened the
end-to-end guarantee that our runtime path really asks PowerShell to
parse the command the way we expect.
This PR attacks the actual cost center instead: it keeps the real
PowerShell parser in the loop, but turns that parser into a long-lived
helper process so both tests and the runtime safe-command path can reuse
it across many requests.
## What Changed
- add `shell-command/src/command_safety/powershell_parser.rs`, which
keeps one mutex-protected parser process per PowerShell executable path
and speaks a simple JSON-over-stdio request/response protocol
- turn `shell-command/src/command_safety/powershell_parser.ps1` into a
long-running parser server with comments explaining the protocol, the
AST-shape restrictions, and why unsupported constructs are rejected
conservatively
- keep request ids and a one-time respawn path so a dead or
desynchronized cached child fails closed instead of silently returning
mixed parser output
- preserve separate parser processes for `powershell.exe` and
`pwsh.exe`, since they do not accept the same language surface
- avoid a direct `PipelineChainAst` type reference in the PowerShell
script so the parser service still runs under Windows PowerShell 5.1 as
well as newer `pwsh`
- make `shell-command/src/command_safety/windows_safe_commands.rs`
delegate to the new parser utility instead of spawning a fresh
PowerShell process for every parse
- add a Windows-only unit test that exercises multiple sequential
requests against the same parser process
## Testing
- adds a Windows-only parser-reuse unit test in `powershell_parser.rs`
- the main end-to-end verification for this change is the Windows CI
lane, because the new service depends on real `powershell.exe` /
`pwsh.exe` behavior
## Summary
- block git global options that can redirect config, repository, or
helper lookup from being auto-approved as safe
- share the unsafe global-option predicate across the Unix and Windows
git safety checks
- add regression coverage for inline and split forms, including `bash
-lc` and PowerShell wrappers
## Root cause
The Unix safe-command gate only rejected `-c` and `--config-env`, even
though the shared git parser already knew how to skip additional
pre-subcommand globals such as `--git-dir`, `--work-tree`,
`--exec-path`, `--namespace`, and `--super-prefix`. That let those
arguments slip through safe-command classification on otherwise
read-only git invocations and bypass approval. The Windows-specific
safe-command path had the same trust-boundary gap for git global
options.
Chris Bookholt