Prefer real pwsh executable on Windows

codex-rs/core/src/shell.rs

@@ -1,5 +1,7 @@
 use crate::shell_detect::detect_shell_type;
 use crate::shell_snapshot::ShellSnapshot;
+use codex_shell_command::powershell::try_find_powershell_executable_blocking;
+use codex_shell_command::powershell::try_find_pwsh_executable_blocking;
 use serde::Deserialize;
 use serde::Serialize;
 use std::path::PathBuf;
@@ -250,15 +252,27 @@ const POWERSHELL_FALLBACK_PATHS: &[&str] =
 const POWERSHELL_FALLBACK_PATHS: &[&str] = &[];
 
 fn get_powershell_shell(path: Option<&PathBuf>) -> Option<Shell> {
-    let shell_path = get_shell_path(ShellType::PowerShell, path, "pwsh", PWSH_FALLBACK_PATHS)
-        .or_else(|| {
+    let shell_path = if path.is_some() {
+        get_shell_path(ShellType::PowerShell, path, "pwsh", PWSH_FALLBACK_PATHS).or_else(|| {
             get_shell_path(
                 ShellType::PowerShell,
                 path,
                 "powershell",
                 POWERSHELL_FALLBACK_PATHS,
             )
-        });
+        })
+    } else {
+        preferred_powershell_path()
+            .or_else(|| get_shell_path(ShellType::PowerShell, path, "pwsh", PWSH_FALLBACK_PATHS))
+            .or_else(|| {
+                get_shell_path(
+                    ShellType::PowerShell,
+                    path,
+                    "powershell",
+                    POWERSHELL_FALLBACK_PATHS,
+                )
+            })
+    };
 
     shell_path.map(|shell_path| Shell {
         shell_type: ShellType::PowerShell,
@@ -267,6 +281,22 @@ fn get_powershell_shell(path: Option<&PathBuf>) -> Option<Shell> {
     })
 }
 
+#[cfg(windows)]
+fn preferred_powershell_path() -> Option<PathBuf> {
+    // Resolve a real PowerShell executable instead of trusting PATH lookup to
+    // hand back an execution alias or batch shim like `pwsh.cmd`.
+    try_find_pwsh_executable_blocking()
+        .map(|path| path.into_path_buf())
+        .or_else(|| {
+            try_find_powershell_executable_blocking().map(|path| path.into_path_buf())
+        })
+}
+
+#[cfg(not(windows))]
+fn preferred_powershell_path() -> Option<PathBuf> {
+    None
+}
+
 fn get_cmd_shell(path: Option<&PathBuf>) -> Option<Shell> {
     let shell_path = get_shell_path(ShellType::Cmd, path, "cmd", &[]);
 

codex-rs/core/src/shell_tests.rs

@@ -1,4 +1,5 @@
 use super::*;
+use codex_shell_command::powershell::try_find_pwsh_executable_blocking;
 use std::path::PathBuf;
 use std::process::Command;
 
@@ -176,7 +177,11 @@ async fn detects_powershell_as_default() {
     let powershell_shell = default_user_shell();
     let shell_path = powershell_shell.shell_path;
 
-    assert!(shell_path.ends_with("pwsh.exe") || shell_path.ends_with("powershell.exe"));
+    if let Some(pwsh_path) = try_find_pwsh_executable_blocking() {
+        assert_eq!(shell_path, pwsh_path.into_path_buf());
+    } else {
+        assert!(shell_path.ends_with("powershell.exe"));
+    }
 }
 
 #[test]
@@ -188,5 +193,9 @@ fn finds_powershell() {
     let powershell_shell = get_shell(ShellType::PowerShell, /*path*/ None).unwrap();
     let shell_path = powershell_shell.shell_path;
 
-    assert!(shell_path.ends_with("pwsh.exe") || shell_path.ends_with("powershell.exe"));
+    if let Some(pwsh_path) = try_find_pwsh_executable_blocking() {
+        assert_eq!(shell_path, pwsh_path.into_path_buf());
+    } else {
+        assert!(shell_path.ends_with("powershell.exe"));
+    }
 }