From 04a10182ab984c9715bc9df73c3906b3648dbd8e Mon Sep 17 00:00:00 2001
From: David Wiesen <iceweasel@openai.com>
Date: Wed, 29 Apr 2026 10:02:51 -0700
Subject: [PATCH] fix windows shell resolution for PowerShell

---
 codex-rs/core/src/shell.rs       | 43 ++++++++++++++++++++++++++++++++
 codex-rs/core/src/shell_tests.rs | 11 ++++++++
 2 files changed, 54 insertions(+)

diff --git a/codex-rs/core/src/shell.rs b/codex-rs/core/src/shell.rs
index 48c760d667..48bd51ac95 100644
--- a/codex-rs/core/src/shell.rs
+++ b/codex-rs/core/src/shell.rs
@@ -1,5 +1,9 @@
 use crate::shell_detect::detect_shell_type;
 use crate::shell_snapshot::ShellSnapshot;
+#[cfg(windows)]
+use codex_shell_command::powershell::try_find_powershell_executable_blocking;
+#[cfg(windows)]
+use codex_shell_command::powershell::try_find_pwsh_executable_blocking;
 use serde::Deserialize;
 use serde::Serialize;
 use std::path::PathBuf;
@@ -250,6 +254,10 @@ const POWERSHELL_FALLBACK_PATHS: &[&str] =
 const POWERSHELL_FALLBACK_PATHS: &[&str] = &[];
 
 fn get_powershell_shell(path: Option<&PathBuf>) -> Option<Shell> {
+    #[cfg(windows)]
+    let shell_path = get_windows_powershell_shell_path(path);
+
+    #[cfg(not(windows))]
     let shell_path = get_shell_path(ShellType::PowerShell, path, "pwsh", PWSH_FALLBACK_PATHS)
         .or_else(|| {
             get_shell_path(
@@ -267,6 +275,41 @@ fn get_powershell_shell(path: Option<&PathBuf>) -> Option<Shell> {
     })
 }
 
+#[cfg(windows)]
+fn get_windows_powershell_shell_path(path: Option<&PathBuf>) -> Option<PathBuf> {
+    if let Some(path) = path.and_then(file_exists)
+        && !is_windows_batch_script(&path)
+    {
+        return Some(path);
+    }
+
+    let default_shell_path = get_user_shell_path();
+    if let Some(default_shell_path) = default_shell_path
+        && detect_shell_type(&default_shell_path) == Some(ShellType::PowerShell)
+        && file_exists(&default_shell_path).is_some()
+        && !is_windows_batch_script(&default_shell_path)
+    {
+        return Some(default_shell_path);
+    }
+
+    try_find_pwsh_executable_blocking()
+        .map(|path| path.into_path_buf())
+        .or_else(|| try_find_powershell_executable_blocking().map(|path| path.into_path_buf()))
+        .or_else(|| {
+            POWERSHELL_FALLBACK_PATHS
+                .iter()
+                .find_map(|path| file_exists(&PathBuf::from(path)))
+        })
+}
+
+#[cfg(windows)]
+fn is_windows_batch_script(path: &std::path::Path) -> bool {
+    matches!(
+        path.extension().and_then(|extension| extension.to_str()),
+        Some(extension) if extension.eq_ignore_ascii_case("cmd") || extension.eq_ignore_ascii_case("bat")
+    )
+}
+
 fn get_cmd_shell(path: Option<&PathBuf>) -> Option<Shell> {
     let shell_path = get_shell_path(ShellType::Cmd, path, "cmd", &[]);
 
diff --git a/codex-rs/core/src/shell_tests.rs b/codex-rs/core/src/shell_tests.rs
index f0974900b2..8ffe143033 100644
--- a/codex-rs/core/src/shell_tests.rs
+++ b/codex-rs/core/src/shell_tests.rs
@@ -190,3 +190,14 @@ fn finds_powershell() {
 
     assert!(shell_path.ends_with("pwsh.exe") || shell_path.ends_with("powershell.exe"));
 }
+
+#[test]
+fn windows_batch_shell_wrappers_are_rejected() {
+    if !cfg!(windows) {
+        return;
+    }
+
+    assert!(is_windows_batch_script(std::path::Path::new("pwsh.cmd")));
+    assert!(is_windows_batch_script(std::path::Path::new("pwsh.bat")));
+    assert!(!is_windows_batch_script(std::path::Path::new("pwsh.exe")));
+}