## What changed
- Add the `apply_patch_preserve_line_endings` feature, disabled by default, to
preserve CRLF, CR, and mixed line endings when `apply_patch` updates files.
- Apply the feature consistently to built-in patch handling and patches invoked
through shell, user-shell, unified-exec, and app-server command execution.
- Keep the active feature configuration authoritative over inherited, shell
snapshot, and client-provided environment values.
## Testing
- Cover line-ending behavior with the feature enabled and disabled for custom
tool calls, shell heredocs, command execution, and the `apply_patch` CLI.
GitOrigin-RevId: 531a7c66761959c650270559f57941929f03e6c4
## Why
Updating a file with `apply_patch` historically normalized its contents to LF,
which can rewrite line endings outside the requested change.
## What changed
- Add an opt-in `PreserveLineEndings` update mode and thread it through patch
verification, application, and the standalone executable. Existing APIs keep
the LF-normalizing mode by default.
- Retain the original endings of untouched and context lines, including in
mixed-ending files, and use the file's first line ending for inserted or
replaced lines.
- Track patch context separately from identical changed lines so preservation
does not alter replacement ordering or matching.
## Testing
Add coverage for CRLF, CR, mixed endings, trailing blank lines, repeated lines,
EOF overlap rejection, and legacy LF normalization.
GitOrigin-RevId: 085f0cbc57e0965aa62c6a2d0e80870424e762f5
- Migrate apply-patch verification and application internals to use the
async `ExecutorFileSystem` abstraction from `exec-server`.
- Convert apply-patch `cwd` handling to `AbsolutePathBuf` through the
verifier/parser/handler boundary.
Doesn't change how the tool itself works.
This PR introduces a `codex-utils-cargo-bin` utility crate that
wraps/replaces our use of `assert_cmd::Command` and
`escargot::CargoBuild`.
As you can infer from the introduction of `buck_project_root()` in this
PR, I am attempting to make it possible to build Codex under
[Buck2](https://buck2.build) as well as `cargo`. With Buck2, I hope to
achieve faster incremental local builds (largely due to Buck2's
[dice](https://buck2.build/docs/insights_and_knowledge/modern_dice/)
build strategy, as well as benefits from its local build daemon) as well
as faster CI builds if we invest in remote execution and caching.
See
https://buck2.build/docs/getting_started/what_is_buck2/#why-use-buck2-key-advantages
for more details about the performance advantages of Buck2.
Buck2 enforces stronger requirements in terms of build and test
isolation. It discourages assumptions about absolute paths (which is key
to enabling remote execution). Because the `CARGO_BIN_EXE_*` environment
variables that Cargo provides are absolute paths (which
`assert_cmd::Command` reads), this is a problem for Buck2, which is why
we need this `codex-utils-cargo-bin` utility.
My WIP-Buck2 setup sets the `CARGO_BIN_EXE_*` environment variables
passed to a `rust_test()` build rule as relative paths.
`codex-utils-cargo-bin` will resolve these values to absolute paths,
when necessary.
---
[//]: # (BEGIN SAPLING FOOTER)
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* #8498
* __->__ #8496
