Preserve script quotes in Windows sandbox cmd invocations (#60624)

## Why

CRT argument escaping adds literal backslashes before quotes in `cmd.exe /c` scripts, breaking quoted paths and executable names.

## What changed

Serialize single-script `cmd /c` invocations with `/s /c` and an outer quote pair, preserving the script's quotes. Share this handling across Windows sandbox process creation, ConPTY, and MXC execution requests.

## Testing

Add a regression test for `certutil -hashfile` with a quoted path containing spaces, and update the command-line test for a quoted PowerShell executable.

GitOrigin-RevId: 32b4b7b55f6af4dba206813eac150310f37ae1d4

codex-rs/mxc-sandbox/src/policy.rs

@@ -15,6 +15,7 @@ use codex_protocol::protocol::FileSystemSandboxPolicy;
 use codex_protocol::protocol::FileSystemSpecialPath;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use codex_utils_path_uri::PathUri;
+use codex_windows_sandbox::cmd_script_command_line;
 use codex_windows_sandbox::expand_windows_deny_read_paths;
 use codex_windows_sandbox::resolve_windows_deny_read_paths;
 use mxc_sdk::mxc_common::cmdline::CommandLineContext;
@@ -320,10 +321,13 @@ pub(super) fn build_request(
         });
     }
     Ok(ExecutionRequest {
-        script_code: cmdline_from_argv_for_context(
-            &command.command,
-            CommandLineContext::WindowsCreateProcess,
-        )?,
+        script_code: match cmd_script_command_line(&command.command) {
+            Some(script) => script,
+            None => cmdline_from_argv_for_context(
+                &command.command,
+                CommandLineContext::WindowsCreateProcess,
+            )?,
+        },
         working_directory: command_cwd
             .to_str()
             .ok_or(PolicyError::NonUnicodeCommandCwd)?

codex-rs/windows-sandbox-rs/src/cmd_script.rs

@@ -0,0 +1,23 @@
+//! Serialize the single script argument used by the Windows command interpreter.
+
+/// Build the native command line for Codex's `cmd.exe /c SCRIPT` invocation.
+/// The script is shell syntax. CRT argument escaping would introduce literal
+/// backslashes before its quotes. With /s, cmd strips exactly the outer pair.
+pub fn cmd_script_command_line(argv: &[String]) -> Option<String> {
+    let [program, switch, script] = argv else {
+        return None;
+    };
+    let name = program.rsplit(['/', '\\']).next()?;
+    if !(name.eq_ignore_ascii_case("cmd.exe") || name.eq_ignore_ascii_case("cmd"))
+        || !switch.eq_ignore_ascii_case("/c")
+        || program.contains(['"', '\0'])
+        || script.contains('\0')
+    {
+        return None;
+    }
+    Some(format!(r#""{program}" /s /c "{script}""#))
+}
+
+#[cfg(test)]
+#[path = "cmd_script_tests.rs"]
+mod tests;

codex-rs/windows-sandbox-rs/src/cmd_script_tests.rs

@@ -0,0 +1,19 @@
+#![cfg(test)]
+
+use super::cmd_script_command_line;
+
+#[test]
+fn preserves_quotes_in_the_hash_command() {
+    let argv = [
+        r"C:\Windows\System32\CMD.EXE",
+        "/C",
+        r#"certutil -hashfile "C:\New folder\long name.pftrace" SHA256"#,
+    ]
+    .map(str::to_owned);
+    assert_eq!(
+        cmd_script_command_line(&argv).as_deref(),
+        Some(
+            r#""C:\Windows\System32\CMD.EXE" /s /c "certutil -hashfile "C:\New folder\long name.pftrace" SHA256""#
+        )
+    );
+}

codex-rs/windows-sandbox-rs/src/conpty/mod.rs

@@ -8,8 +8,8 @@
 
 use crate::desktop::LaunchDesktop;
 use crate::proc_thread_attr::ProcThreadAttributeList;
+use crate::winutil::argv_to_command_line;
 use crate::winutil::format_last_error;
-use crate::winutil::quote_windows_arg;
 use crate::winutil::to_wide;
 use anyhow::Context;
 use anyhow::Result;
@@ -112,11 +112,7 @@ pub fn spawn_conpty_process_as_user(
     env_map: &HashMap<String, String>,
     desktop: LaunchDesktop,
 ) -> Result<(PROCESS_INFORMATION, ConptyInstance)> {
-    let cmdline_str = argv
-        .iter()
-        .map(|arg| quote_windows_arg(arg))
-        .collect::<Vec<_>>()
-        .join(" ");
+    let cmdline_str = argv_to_command_line(argv);
     let mut cmdline: Vec<u16> = to_wide(&cmdline_str);
     let env_block = make_env_block(env_map);
     let mut si: STARTUPINFOEXW = unsafe { std::mem::zeroed() };

codex-rs/windows-sandbox-rs/src/lib.rs

@@ -155,6 +155,9 @@ mod winutil;
 #[cfg(target_os = "windows")]
 mod workspace_acl;
 
+mod cmd_script;
+pub use cmd_script::cmd_script_command_line;
+
 mod deny_read_resolver;
 #[cfg(target_os = "windows")]
 mod uninstall_windows;

codex-rs/windows-sandbox-rs/src/winutil.rs

@@ -114,6 +114,9 @@ pub fn quote_windows_arg(arg: &str) -> String {
 /// Build a Windows command line for CreateProcess-style APIs.
 #[cfg(target_os = "windows")]
 pub fn argv_to_command_line(argv: &[String]) -> String {
+    if let Some(command_line) = crate::cmd_script_command_line(argv) {
+        return command_line;
+    }
     argv.iter()
         .map(|arg| quote_windows_arg(arg))
         .collect::<Vec<_>>()
@@ -330,7 +333,7 @@ mod tests {
     use pretty_assertions::assert_eq;
 
     #[test]
-    fn argv_to_command_line_quotes_each_argument_independently() {
+    fn argv_to_command_line_preserves_quoted_executable_in_cmd_script() {
         let argv = vec![
             "cmd.exe".to_string(),
             "/c".to_string(),
@@ -340,7 +343,7 @@ mod tests {
 
         assert_eq!(
             argv_to_command_line(&argv),
-            "cmd.exe /c \"\\\"C:\\Program Files\\PowerShell\\7\\pwsh.exe\\\" -NoProfile -EncodedCommand abc==\""
+            r#""cmd.exe" /s /c ""C:\Program Files\PowerShell\7\pwsh.exe" -NoProfile -EncodedCommand abc==""#
         );
     }