first pass of merging in warp (doesn't build)

crates/command/src/async.rs

@@ -2,13 +2,13 @@
 // wrapper implementation that allows us to not import the above type elsewhere in this workspace.
 #![allow(clippy::disallowed_types)]
 
-use async_process::Child;
 use std::ffi::OsStr;
-use std::fmt;
 use std::future::Future;
-use std::io;
 use std::path::Path;
 use std::process::{ExitStatus, Output, Stdio};
+use std::{fmt, io};
+
+use async_process::Child;
 
 /// Wrapper around a [`async_process::Command`] that ensures any new Command is set with the windows
 /// `CREATE_NO_WINDOW` flag to avoid a console window temporarily popping up.
@@ -39,6 +39,7 @@ impl Command {
     /// let mut cmd = Command::new("ls");
     /// ```
     pub fn new<S: AsRef<OsStr>>(program: S) -> Command {
+        let program = crate::wsl::translate_program_for_spawn(program.as_ref());
         let inner = async_process::Command::new(program);
         Self::new_internal(inner)
     }
@@ -51,6 +52,7 @@ impl Command {
     /// See [`setsid(2)`](https://man7.org/linux/man-pages/man2/setsid.2.html).
     #[cfg(unix)]
     pub fn new_with_session<S: AsRef<OsStr>>(program: S) -> Command {
+        let program = crate::wsl::translate_program_for_spawn(program.as_ref());
         let mut command = std::process::Command::new(program);
 
         // SAFETY: `pre_exec` requires the closure to be async-signal-safe.
@@ -77,6 +79,7 @@ impl Command {
     /// This allows for killing any other processes spawned by this process
     /// when we kill this process.
     pub fn new_with_process_group<S: AsRef<OsStr>>(program: S) -> Command {
+        let program = crate::wsl::translate_program_for_spawn(program.as_ref());
         #[allow(unused_mut)]
         let mut command = std::process::Command::new(program);
 

crates/command/src/blocking.rs

@@ -66,6 +66,7 @@ impl Command {
     ///     .expect("sh command failed to start");
     /// ```
     pub fn new<S: AsRef<OsStr>>(program: S) -> Command {
+        let program = crate::wsl::translate_program_for_spawn(program.as_ref());
         #[cfg_attr(not(windows), expect(unused_mut))]
         let mut inner = std::process::Command::new(program);
 
@@ -97,7 +98,6 @@ impl Command {
     ///
     /// [1]: https://msdn.microsoft.com/en-us/library/windows/desktop/ms684863(v=vs.85).aspx
     pub fn creation_flags(&mut self, flags: u32) -> &mut Self {
-        use std::os::windows::process::CommandExt;
         let flags = windows::Win32::System::Threading::CREATE_NO_WINDOW.0 | flags;
         self.inner.creation_flags(flags);
         self

crates/command/src/lib.rs

@@ -13,5 +13,6 @@ pub mod blocking;
 pub mod unix;
 #[cfg(windows)]
 pub mod windows;
+pub mod wsl;
 
 pub use std::process::{ExitStatus, Output, Stdio};

crates/command/src/unix.rs

@@ -1,9 +1,10 @@
-use async_process::unix::CommandExt as _;
 use std::ffi::OsStr;
 use std::io;
 use std::io::Error;
 use std::os::unix::process::CommandExt as _;
 
+use async_process::unix::CommandExt as _;
+
 /// Unix-specific extensions to the [`Command`] builder.
 ///
 /// This trait is sealed: it cannot be implemented outside `async-process`.

crates/command/src/wsl.rs

@@ -0,0 +1,128 @@
+//! WSL detection and Linux-side binary resolution for subprocess
+//! invocations made through this crate's [`Command`](crate::r#async::Command)
+//! and [`Command`](crate::blocking::Command) wrappers.
+//!
+//! Warp ships as a Linux ELF that users routinely run inside WSL.
+//! WSL's default `appendWindowsPath = true` (in `/etc/wsl.conf`)
+//! puts directories like `/mnt/c/Program Files/Git/cmd/` on `PATH`,
+//! so a bare `Command::new("git")` can resolve to Windows `git.exe`
+//! through WSL interop. That path is dramatically slower, can
+//! mishandle Linux paths, and breaks Linux-side hooks.
+//!
+//! [`translate_program_for_spawn`] is invoked from the wrappers'
+//! `new` constructors and transparently substitutes the program
+//! string when (a) we're inside WSL and (b) the program is a bare
+//! name in [`KNOWN_NAMES`]. Path-qualified or unknown programs are
+//! passed through unchanged. Resolution is cached for the life of
+//! the process — PATH is effectively static for the host process.
+//!
+//! The same `/mnt/*` filtering precedent is used for `compgen` in
+//! `app/src/terminal/model/session/command_executor/wsl_command_executor.rs`.
+
+use std::ffi::{OsStr, OsString};
+use std::path::{Path, PathBuf};
+use std::sync::OnceLock;
+
+#[cfg(test)]
+#[path = "wsl_tests.rs"]
+mod tests;
+
+/// Bare program names whose resolution Warp wants to override under
+/// WSL. Anything not in this list is passed through unchanged.
+const KNOWN_NAMES: &[&str] = &["git", "gh"];
+
+/// True when the current process is running inside a WSL guest.
+/// Cached for the life of the process.
+pub fn is_wsl() -> bool {
+    static IS_WSL: OnceLock<bool> = OnceLock::new();
+    *IS_WSL.get_or_init(|| Path::new("/proc/sys/fs/binfmt_misc/WSLInterop").exists())
+}
+
+/// Translate a `Command::new` program string. On WSL, bare names in
+/// [`KNOWN_NAMES`] are resolved to the first executable on `PATH`
+/// outside `/mnt/*`; everything else is returned unchanged so the OS
+/// performs its normal lookup at spawn time.
+pub(crate) fn translate_program_for_spawn(program: &OsStr) -> OsString {
+    if !is_wsl() {
+        return program.to_owned();
+    }
+    let Some(name) = known_bare_name(program) else {
+        return program.to_owned();
+    };
+    cached_resolve(name).to_owned()
+}
+
+/// Returns the program's name when it's a bare entry in
+/// [`KNOWN_NAMES`]. Paths and absolute names are filtered out so a
+/// caller that already specified `/usr/bin/git` is not touched.
+fn known_bare_name(program: &OsStr) -> Option<&'static str> {
+    let s = program.to_str()?;
+    if s.contains('/') || s.contains('\\') {
+        return None;
+    }
+    KNOWN_NAMES.iter().copied().find(|&n| n == s)
+}
+
+fn cached_resolve(name: &'static str) -> &'static OsString {
+    static GIT: OnceLock<OsString> = OnceLock::new();
+    static GH: OnceLock<OsString> = OnceLock::new();
+    let cell = match name {
+        "git" => &GIT,
+        "gh" => &GH,
+        // `KNOWN_NAMES` is exhaustive over the static cells above; if
+        // a new name is added there it must also be wired here.
+        _ => unreachable!("unknown name {name:?}"),
+    };
+    cell.get_or_init(|| {
+        let path_env = std::env::var_os("PATH");
+        match resolve_binary_in_wsl_safe_path(name, path_env.as_deref(), true) {
+            Some(p) => p.into_os_string(),
+            None => {
+                log::warn!(
+                    "wsl: no Linux-side `{name}` found on PATH (excluding /mnt/*); \
+                     falling back to bare `{name}` which may resolve to a Windows .exe"
+                );
+                OsString::from(name)
+            }
+        }
+    })
+}
+
+/// Returns the first executable named `name` on `path_env`, skipping
+/// any PATH entry under `/mnt/` when `is_wsl` is true. Returns `None`
+/// if no acceptable match exists. Pure — exposed for unit testing
+/// without depending on a real WSL host.
+pub fn resolve_binary_in_wsl_safe_path(
+    name: &str,
+    path_env: Option<&OsStr>,
+    is_wsl: bool,
+) -> Option<PathBuf> {
+    let path_env = path_env?;
+    for dir in std::env::split_paths(path_env) {
+        if is_wsl && dir.starts_with("/mnt") {
+            continue;
+        }
+        let candidate = dir.join(name);
+        if is_executable_file(&candidate) {
+            return Some(candidate);
+        }
+    }
+    None
+}
+
+#[cfg(unix)]
+fn is_executable_file(path: &Path) -> bool {
+    use std::os::unix::fs::PermissionsExt as _;
+    match std::fs::metadata(path) {
+        Ok(md) => md.is_file() && (md.permissions().mode() & 0o111 != 0),
+        Err(_) => false,
+    }
+}
+
+#[cfg(not(unix))]
+fn is_executable_file(_path: &Path) -> bool {
+    // The WSL-safe resolver only runs on Linux. Other targets short-
+    // circuit through `is_wsl() == false`, so this stub is unreachable
+    // in practice — present only to keep the crate compiling.
+    false
+}

crates/command/src/wsl_tests.rs

@@ -0,0 +1,173 @@
+use std::ffi::OsStr;
+#[cfg(unix)]
+use std::ffi::OsString;
+#[cfg(unix)]
+use std::fs;
+#[cfg(unix)]
+use std::path::PathBuf;
+
+use super::{known_bare_name, resolve_binary_in_wsl_safe_path};
+
+#[cfg(unix)]
+fn make_executable(path: &std::path::Path) {
+    use std::os::unix::fs::PermissionsExt as _;
+    let mut perms = fs::metadata(path).unwrap().permissions();
+    perms.set_mode(0o755);
+    fs::set_permissions(path, perms).unwrap();
+}
+
+#[cfg(unix)]
+fn write_exec(path: &std::path::Path) {
+    fs::write(path, b"#!/bin/sh\nexit 0\n").unwrap();
+    make_executable(path);
+}
+
+#[cfg(unix)]
+fn join(parts: &[PathBuf]) -> OsString {
+    std::env::join_paths(parts).unwrap()
+}
+
+#[cfg(unix)]
+#[test]
+fn picks_first_linux_path_when_wsl() {
+    let linux_dir = tempfile::tempdir().unwrap();
+    write_exec(&linux_dir.path().join("git"));
+
+    // `/mnt/c/...` paths in the synthetic PATH that don't exist on
+    // disk simulate the WSL-with-Windows-git layout: the resolver
+    // should skip them on the prefix and never stat them.
+    let path_env = join(&[
+        PathBuf::from("/mnt/c/Program Files/Git/cmd"),
+        linux_dir.path().to_path_buf(),
+    ]);
+
+    let resolved =
+        resolve_binary_in_wsl_safe_path("git", Some(path_env.as_os_str()), true).unwrap();
+    assert_eq!(resolved, linux_dir.path().join("git"));
+    assert!(!resolved.starts_with("/mnt"));
+}
+
+#[cfg(unix)]
+#[test]
+fn passes_through_first_match_when_not_wsl() {
+    // When not WSL, `/mnt/...` is just another directory; the resolver
+    // should pick the first dir on PATH that contains an exec match.
+    let mnt_dir = tempfile::tempdir().unwrap();
+    write_exec(&mnt_dir.path().join("git"));
+    let other_dir = tempfile::tempdir().unwrap();
+    write_exec(&other_dir.path().join("git"));
+
+    let path_env = join(&[mnt_dir.path().to_path_buf(), other_dir.path().to_path_buf()]);
+
+    let resolved =
+        resolve_binary_in_wsl_safe_path("git", Some(path_env.as_os_str()), false).unwrap();
+    assert_eq!(resolved, mnt_dir.path().join("git"));
+}
+
+#[cfg(unix)]
+#[test]
+fn falls_back_to_none_when_only_mnt_has_git() {
+    let path_env = join(&[
+        PathBuf::from("/mnt/c/Program Files/Git/cmd"),
+        PathBuf::from("/mnt/c/Windows/System32"),
+    ]);
+    assert!(resolve_binary_in_wsl_safe_path("git", Some(path_env.as_os_str()), true).is_none());
+}
+
+#[cfg(unix)]
+#[test]
+fn picks_user_local_bin() {
+    let bin_dir = tempfile::tempdir().unwrap();
+    let empty_dir = bin_dir.path().join("empty");
+    fs::create_dir_all(&empty_dir).unwrap();
+    let local_bin = bin_dir.path().join("home/.local/bin");
+    fs::create_dir_all(&local_bin).unwrap();
+    write_exec(&local_bin.join("git"));
+
+    // PATH order: an empty dir, then a `/mnt/...` candidate that
+    // should be skipped on WSL, then the directory with the real
+    // exec. The resolver must walk past the first two and land on
+    // the third.
+    let path_env = join(&[
+        empty_dir,
+        PathBuf::from("/mnt/c/Program Files/Git/cmd"),
+        local_bin.clone(),
+    ]);
+    let resolved =
+        resolve_binary_in_wsl_safe_path("git", Some(path_env.as_os_str()), true).unwrap();
+    assert_eq!(resolved, local_bin.join("git"));
+}
+
+#[cfg(unix)]
+#[test]
+fn follows_symlinks() {
+    let dir = tempfile::tempdir().unwrap();
+    let real = dir.path().join("git-wrapper");
+    write_exec(&real);
+    let link = dir.path().join("git");
+    std::os::unix::fs::symlink(&real, &link).unwrap();
+
+    let path_env = join(&[dir.path().to_path_buf()]);
+    let resolved =
+        resolve_binary_in_wsl_safe_path("git", Some(path_env.as_os_str()), true).unwrap();
+    assert_eq!(resolved, link);
+}
+
+#[cfg(unix)]
+#[test]
+fn skips_non_executable() {
+    let dir = tempfile::tempdir().unwrap();
+    fs::write(dir.path().join("git"), b"not exec").unwrap();
+    // Intentionally do NOT chmod +x.
+
+    let path_env = join(&[dir.path().to_path_buf()]);
+    assert!(resolve_binary_in_wsl_safe_path("git", Some(path_env.as_os_str()), true).is_none());
+}
+
+#[test]
+fn handles_empty_path_env() {
+    assert!(resolve_binary_in_wsl_safe_path("git", None, true).is_none());
+    assert!(resolve_binary_in_wsl_safe_path("git", None, false).is_none());
+}
+
+#[cfg(unix)]
+#[test]
+fn handles_non_utf8_path_components() {
+    use std::os::unix::ffi::OsStringExt as _;
+
+    let dir = tempfile::tempdir().unwrap();
+    write_exec(&dir.path().join("git"));
+
+    // Build a PATH whose first component is a non-UTF-8 byte sequence,
+    // followed by a real directory. The resolver must walk past the
+    // garbage entry without panicking and find the valid one.
+    let mut bytes = b"/\xff\xfe/bad:".to_vec();
+    bytes.extend_from_slice(dir.path().as_os_str().as_encoded_bytes());
+    let path_env = OsString::from_vec(bytes);
+
+    let resolved =
+        resolve_binary_in_wsl_safe_path("git", Some(path_env.as_os_str()), true).unwrap();
+    assert_eq!(resolved, dir.path().join("git"));
+}
+
+#[test]
+fn known_bare_name_recognizes_git_and_gh() {
+    assert_eq!(known_bare_name(OsStr::new("git")), Some("git"));
+    assert_eq!(known_bare_name(OsStr::new("gh")), Some("gh"));
+}
+
+#[test]
+fn known_bare_name_skips_paths() {
+    assert_eq!(known_bare_name(OsStr::new("/usr/bin/git")), None);
+    assert_eq!(known_bare_name(OsStr::new("./git")), None);
+    assert_eq!(known_bare_name(OsStr::new("bin/git")), None);
+    #[cfg(windows)]
+    assert_eq!(known_bare_name(OsStr::new("C:\\git\\git.exe")), None);
+}
+
+#[test]
+fn known_bare_name_skips_unknowns() {
+    assert_eq!(known_bare_name(OsStr::new("ls")), None);
+    assert_eq!(known_bare_name(OsStr::new("python")), None);
+    assert_eq!(known_bare_name(OsStr::new("")), None);
+}