Codex forces `core.fsmonitor=false` on internal Git commands so a
repository cannot select an executable fsmonitor helper. This also
disables Git's built-in daemon for `status`, `diff`, and `ls-files`,
turning those worktree reads into full scans in large repositories.
Read the raw effective `core.fsmonitor` value and preserve it only when
Git interprets it as true and advertises built-in daemon support through
`git version --build-options`. Query uncommon boolean spellings back
through Git using the exact effective value. Unset, false, helper paths,
malformed values, probe failures, and unsupported Git builds continue to
force `core.fsmonitor=false`.
Centralize this policy in `git-utils` while keeping process execution in
the existing local and workspace-command adapters. Probe once per
worktree workflow and reuse the result for its Git commands, including
the TUI `/diff` path. Metadata-only commands and repository discovery
remain disabled without probing. Each probe and requested Git process
keeps its own existing timeout, and the decision is not cached because
layered and conditional Git configuration can change while Codex runs.
---------
Co-authored-by: Chris Bookholt <bookholt@openai.com>
## Why
`/diff` is intended to display working-tree changes, but its Git
invocations honored repository-selected executable helpers. A repository
could configure diff/text conversion helpers, clean/process filters,
`core.fsmonitor`, or `post-index-change` hooks that execute when a user
runs `/diff`.
Fixes
[PSEC-4395](https://linear.app/openai/issue/PSEC-4395/codex-cli-diff-executes-repository-selected-diff-helpers).
## What Changed
- Pass `--no-textconv` and `--no-ext-diff` for tracked and untracked
diff generation.
- Discover configured `filter.<driver>.clean` and `.process` entries,
then neutralize the selected drivers through structured
`GIT_CONFIG_KEY_*` / `GIT_CONFIG_VALUE_*` overrides, including driver
names containing `=`.
- Run all `/diff` Git probes with `core.fsmonitor=false` and a null
`core.hooksPath`.
- Use short submodule reporting while ignoring dirty submodule
worktrees, since inspecting a checked-out submodule for dirtiness can
execute filters from that child repository. This intentionally omits
dirty-only submodule markers in order to preserve the non-executing
security boundary.
- Add real-Git marker tests covering filters, fsmonitor, hooks, and
configured helpers inside checked-out submodules.
## How to Test
1. In a repository with ordinary tracked and untracked edits, run
`/diff`.
2. Confirm the normal working-tree diff is shown for top-level files.
3. Run the targeted tests below; they configure executable marker
helpers for repository filters, fsmonitor, hooks, and a checked-out
submodule, then verify `/diff` does not invoke them.
4. Confirm a dirty-only submodule does not cause Codex to enter the
submodule and execute its configured helper.
Targeted tests:
- `just test -p codex-tui get_git_diff_`
Validation note: `just test -p codex-tui` runs the new coverage, but
this worktree currently also has two unrelated failing guardian tests:
`app::tests::update_feature_flags_disabling_guardian_clears_review_policy_and_restores_default`
and
`app::tests::update_feature_flags_disabling_guardian_clears_manual_review_policy_without_history`.
Stacked on #20892.
## Why
#20892 adds the TUI workspace command abstraction so branch status
metadata can run through app-server instead of assuming the CLI process
has the active workspace locally. `/diff` still used direct local
process execution, which means remote app-server sessions could compute
the diff against the wrong machine or fail to see the active workspace
at all.
This PR moves `/diff` onto that same app-server-backed command path so
Git runs wherever the active workspace lives.
## What Changed
- Route `/diff` through the TUI `WorkspaceCommandExecutor` using the
active chat cwd.
- Replace direct `tokio::process::Command` usage in `get_git_diff` with
argv-based workspace command requests.
- Preserve the existing `/diff` behavior: tracked diff output, untracked
file diffs, treating Git diff exit code `1` as success, and showing the
existing non-git-repository message.
- Extend `WorkspaceCommand` with caller-set timeouts and an explicit
uncapped-output opt-out. Metadata probes remain capped by default;
`/diff` opts out because its full output is the user-visible payload.
## How to Test
Manual reviewer path:
1. Start the Codex TUI from a Git worktree with one tracked file change
and one untracked file.
2. Run `/diff`.
3. Confirm the rendered diff includes both the tracked diff and the
untracked file diff.
4. Start the TUI outside a Git worktree, or switch to a non-git cwd,
then run `/diff`.
5. Confirm it shows the existing `/diff` not-inside-a-git-repository
message.
Targeted tests run:
- `cargo test -p codex-tui get_git_diff -- --nocapture`
- `cargo test -p codex-tui branch_summary -- --nocapture`
- `cargo test -p codex-tui`
This is a follow-up to https://github.com/openai/codex/pull/15922. That
previous PR deleted the old `tui` directory and left the new
`tui_app_server` directory in place. This PR renames `tui_app_server` to
`tui` and fixes up all references.
This is the part 1 of 2 PRs that will delete the `tui` /
`tui_app_server` split. This part simply deletes the existing `tui`
directory and marks the `tui_app_server` feature flag as removed. I left
the `tui_app_server` feature flag in place for now so its presence
doesn't result in an error. It is simply ignored.
Part 2 will rename the `tui_app_server` directory `tui`. I did this as
two parts to reduce visible code churn.
## Summary
- Show a temporary Working on diff state in the bottom pan
- Add `DiffResult` app event and dispatch git diff asynchronously
## Testing
- `just fmt`
- `just fix` *(fails: `let` expressions in this position are unstable)*
- `cargo test --all-features` *(fails: `let` expressions in this
position are unstable)*
------
https://chatgpt.com/codex/tasks/task_i_689a839f32b88321840a893551d5fbef
Adds support for a `/diff` command comparable to the one available in
the TypeScript CLI.
<img width="1103" alt="Screenshot 2025-06-26 at 12 31 33 PM"
src="https://github.com/user-attachments/assets/5dc646ca-301f-41ff-92a7-595c68db64b6"
/>
While here, changed the `SlashCommand` enum so the declared variant
order is the order the commands appear in the popup menu. This way,
`/toggle-mouse-mode` is listed last, as it is the least likely to be
used.
Fixes https://github.com/openai/codex/issues/1253.