term, cli: `winsplit` over `shlex` on Windows

Command line parsing differs on Windows vs. POSIX compliant operating
systems (just consider the differences in handling `\` for paths vs. as
a marker for escape sequences). Thus, on Windows use `winsplit` to
split command arguments instead of `shlex` for Unix-like OSes.

`winsplit` is a small crate with no other dependencies.

CHANGELOG.md

@@ -20,6 +20,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Fixed Bugs
 
+- When preparing commands to execute, the `shlex` crate was used on all platforms.
+  The semantics on Windows are different (e.g. '\' is a path separator on Windows
+  but marks an escape sequence on Unix-like systems), which lead to issues when
+  attempting to execute child processes.
+  This is fixed by using `winsplit` on Windows instead.
+
 ## Deprecations
 
 - The `rad fork` command was confusing, and mislead users as to what its purpose

Cargo.lock

@@ -2888,6 +2888,7 @@ dependencies = [
  "tree-sitter-rust",
  "tree-sitter-toml-ng",
  "tree-sitter-typescript",
+ "winsplit",
  "zeroize",
 ]
 
@@ -2902,6 +2903,7 @@ dependencies = [
  "shlex",
  "snapbox",
  "thiserror 2.0.17",
+ "winsplit",
 ]
 
 [[package]]
@@ -3201,6 +3203,7 @@ dependencies = [
  "thiserror 2.0.17",
  "unicode-display-width",
  "unicode-segmentation",
+ "winsplit",
  "zeroize",
 ]
 
@@ -5107,6 +5110,12 @@ dependencies = [
  "windows",
 ]
 
+[[package]]
+name = "winsplit"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ab703352da6a72f35c39a533526393725640575bb211f61987a2748323ad956"
+
 [[package]]
 name = "wit-bindgen-rt"
 version = "0.39.0"

Cargo.toml

@@ -69,6 +69,7 @@ sqlite = "0.32.0"
 tempfile = "3.3.0"
 thiserror = { version = "2", default-features = false }
 winpipe = "0.1.1"
+winsplit = "0.1.0"
 zeroize = "1.5.7"
 
 # Crates from the "radicle-git" workspace. These should be synced manually.

crates/radicle-cli-test/Cargo.toml

@@ -16,6 +16,11 @@ escargot = "0.5.7"
 log = { workspace = true, features = ["std"] }
 pretty_assertions = { workspace = true }
 radicle = { workspace = true, features = ["logger", "test"]}
-shlex = { workspace = true }
 snapbox = { workspace = true }
-thiserror = { workspace = true, default-features = true }
+thiserror = { workspace = true, default-features = true }
+
+[target.'cfg(unix)'.dependencies]
+shlex = { workspace = true }
+
+[target.'cfg(windows)'.dependencies]
+winsplit = { workspace = true }

crates/radicle-cli-test/src/lib.rs

@@ -353,7 +353,13 @@ impl TestFormula {
                     content.push('\n');
                 } else if let Some(line) = line.strip_prefix('$') {
                     let line = line.trim();
+
+                    #[cfg(unix)]
                     let parts = shlex::split(line).ok_or(Error::Parse)?;
+
+                    #[cfg(windows)]
+                    let parts = winsplit::split(line);
+
                     let (cmd, args) = parts.split_first().ok_or(Error::Parse)?;
 
                     test.assertions.push(Assertion {

crates/radicle-cli/Cargo.toml

@@ -33,7 +33,6 @@ radicle-term = { workspace = true }
 schemars = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
-shlex = { workspace = true }
 tempfile = { workspace = true }
 thiserror = { workspace = true, default-features = true }
 timeago = { version = "0.4.2", default-features = false }
@@ -53,6 +52,12 @@ tree-sitter-toml-ng = "0.6.0"
 tree-sitter-typescript = "0.23.2"
 zeroize = { workspace = true }
 
+[target.'cfg(unix)'.dependencies]
+shlex = { workspace = true }
+
+[target.'cfg(windows)'.dependencies]
+winsplit = { workspace = true }
+
 [dev-dependencies]
 pretty_assertions = { workspace = true }
 radicle = { workspace = true, features = ["test"] }

crates/radicle-cli/src/pager.rs

@@ -21,9 +21,14 @@ pub fn run(elem: impl Element) -> io::Result<()> {
     let Some(pager) = radicle::profile::env::pager() else {
         return elem.write(Constraint::UNBOUNDED);
     };
+
+    #[cfg(unix)]
     let Some(parts) = shlex::split(&pager) else {
         return elem.write(Constraint::UNBOUNDED);
     };
+    #[cfg(windows)]
+    let parts = winsplit::split(&pager);
+
     let Some((program, args)) = parts.split_first() else {
         return elem.write(Constraint::UNBOUNDED);
     };

crates/radicle-term/Cargo.toml

@@ -25,12 +25,15 @@ unicode-display-width = "0.3.0"
 unicode-segmentation = "1.7.1"
 zeroize = { workspace = true }
 git2 = { workspace = true, optional = true }
-shlex = { workspace = true }
 
 [target.'cfg(unix)'.dependencies]
 crossbeam-channel = { workspace = true }
 libc = { workspace = true }
 radicle-signals = { workspace = true }
+shlex = { workspace = true }
+
+[target.'cfg(windows)'.dependencies]
+winsplit = { workspace = true }
 
 [dev-dependencies]
 pretty_assertions = { workspace = true }

crates/radicle-term/src/editor.rs

@@ -110,12 +110,20 @@ impl Editor {
                 "editor not configured: the `EDITOR` environment variable is not set",
             ));
         };
-        let Some(parts) = shlex::split(cmd.to_string_lossy().as_ref()) else {
+
+        let lossy = cmd.to_string_lossy();
+
+        #[cfg(unix)]
+        let Some(parts) = shlex::split(&lossy) else {
             return Err(io::Error::new(
                 io::ErrorKind::InvalidInput,
                 format!("invalid editor command {cmd:?}"),
             ));
         };
+
+        #[cfg(windows)]
+        let parts = winsplit::split(&lossy);
+
         let Some((program, args)) = parts.split_first() else {
             return Err(io::Error::new(
                 io::ErrorKind::InvalidInput,