fix: open scrollback editor on windows without sh

refs #914

AGENTS.md

@@ -113,6 +113,7 @@ external contributor guardrail.
 ### Windows VM validation
 
 The Windows VM is for final/manual Windows validation, not normal agent work.
+Connect to it with the `windows-wirt` SSH alias.
 
 Use the single reusable checkout at `C:\work\repo`. Do not create additional
 persistent Herdr clones or worktrees on the VM. The Windows account is already
@@ -121,11 +122,15 @@ named `herdr`, so avoid paths like `C:\Users\herdr\herdr`.
 Before validating a fix on Windows, sync or apply the Linux worktree changes
 into `C:\work\repo`, then run the needed Windows build or test commands there.
 Reuse the shared Rust caches under `C:\Users\herdr\.cargo` and
-`C:\Users\herdr\.rustup`. Do not use WSL on the VM.
+`C:\Users\herdr\.rustup`. Do not use WSL on the VM. The VM may have a newer
+Zig on `PATH`; Herdr currently requires Zig 0.15.2, so set
+`$env:ZIG = "C:\Users\herdr\zig-0.15.2\zig.exe"` before running Cargo commands
+that build the vendored libghostty-vt.
 
 After validation, leave `C:\work\repo` clean. Remove temporary files and delete
 `C:\work\repo\target` when disk space is tight, but keep the shared Cargo and
-Rustup caches.
+Rustup caches. Unless Can explicitly asks to keep the patched tree for more
+manual testing, reset `C:\work\repo` back to a clean checkout before finishing.
 
 ## Agent Detection Updates
 

docs/next/CHANGELOG.md

@@ -15,6 +15,7 @@
 - Bumped the client/server protocol version to 15 for socket API placement mutation event and response compatibility.
 
 ### Fixed
+- `prefix+e` scrollback editor panes now open on Windows without trying to run `/bin/sh`; Windows uses `VISUAL`, then `EDITOR`, then `notepad.exe` as the fallback editor. (#914)
 - `herdr pane split --current` now resolves to the calling Herdr pane instead of the UI-focused pane when run inside a pane. (#902)
 - Native Windows clients running inside Alacritty now preserve mouse reports and `ctrl+j` input instead of leaking mouse escape sequences into panes. `shift+enter` remains dependent on whether the outer terminal reports it as a distinct modified Enter key. (#792)
 - OMP integration state now recovers after resumed sessions such as `omp -c` and reports Ask/tool approval waits as blocked instead of leaving the pane working or stuck on the previous OMP session. (#879)

src/app/input/navigate.rs

@@ -820,14 +820,27 @@ impl App {
 
         let path = write_scrollback_temp_file(&scrollback)?;
 
-        let quoted_path = shell_quote(&path.display().to_string());
-        let command = format!(
-            r#"scrollback_file={quoted_path}; eval "${{EDITOR:-vi}} \"\$scrollback_file\""; status=$?; rm -f "$scrollback_file"; exit $status"#
-        );
-        if let Err(err) = self.spawn_pane_command(&command, vec![path.clone()]) {
-            let _ = fs::remove_file(&path);
-            return Err(err);
-        }
+        let argv = match crate::platform::scrollback_editor_argv(&path) {
+            Ok(argv) => argv,
+            Err(err) => {
+                let _ = fs::remove_file(&path);
+                return Err(err);
+            }
+        };
+        let (env, _) = self.custom_command_env();
+        let new_pane = match self.spawn_overlay_argv_command(&argv, None, env, vec![path.clone()]) {
+            Ok((_, new_pane)) => new_pane,
+            Err(err) => {
+                let _ = fs::remove_file(&path);
+                return Err(err);
+            }
+        };
+        let terminal_id = new_pane.terminal.id.clone();
+        self.terminal_runtimes
+            .insert(terminal_id.clone(), new_pane.runtime);
+        self.state
+            .remove_alias_shadowed_by_new_pane(new_pane.pane_id);
+        self.state.terminals.insert(terminal_id, new_pane.terminal);
 
         if let Some(public_pane_id) = self.public_pane_id(ws_idx, pane_id) {
             self.state.toast = Some(crate::app::state::ToastNotification {
@@ -1677,22 +1690,6 @@ fn unique_scrollback_path(attempt: u32) -> std::path::PathBuf {
     ))
 }
 
-fn shell_quote(value: &str) -> String {
-    if !value.is_empty()
-        && value.chars().all(|ch| {
-            ch.is_ascii_alphanumeric()
-                || matches!(
-                    ch,
-                    '@' | '%' | '_' | '+' | '=' | ':' | ',' | '.' | '/' | '-'
-                )
-        })
-    {
-        return value.to_string();
-    }
-
-    format!("'{}'", value.replace('\'', "'\\''"))
-}
-
 #[cfg(test)]
 mod tests {
     #[cfg(unix)]
@@ -2797,6 +2794,13 @@ last_pane = "prefix+tab"
         assert!(content.contains("alpha"));
         assert!(content.contains("beta"));
         assert_eq!(app.state.mode, Mode::Terminal);
+        assert!(
+            app.state.terminals.values().any(|terminal| terminal
+                .launch_argv
+                .as_ref()
+                .is_some_and(|argv| argv.first().is_some_and(|program| program == "/bin/sh"))),
+            "scrollback editor should launch through argv overlay path"
+        );
 
         let _ = std::fs::remove_file(output_path);
     }

src/platform/fallback.rs

@@ -6,6 +6,14 @@ use super::{ClipboardImage, ForegroundJob, Signal};
 /// Unsupported platform stub.
 pub fn raise_server_nofile_limit() {}
 
+/// Unsupported platform stub.
+pub(crate) fn scrollback_editor_argv(_path: &std::path::Path) -> std::io::Result<Vec<String>> {
+    Err(std::io::Error::new(
+        std::io::ErrorKind::Unsupported,
+        "opening scrollback in an editor is not supported on this platform",
+    ))
+}
+
 /// Unsupported platform stub.
 pub fn detach_server_daemon_command(_command: &mut Command) {}
 

src/platform/linux.rs

@@ -12,6 +12,30 @@ use super::{
 
 pub fn raise_server_nofile_limit() {}
 
+pub(crate) fn scrollback_editor_argv(path: &std::path::Path) -> std::io::Result<Vec<String>> {
+    let quoted_path = shell_quote(&path.display().to_string());
+    let command = format!(
+        r#"scrollback_file={quoted_path}; eval "${{EDITOR:-vi}} \"\$scrollback_file\""; status=$?; rm -f "$scrollback_file"; exit $status"#
+    );
+    Ok(vec!["/bin/sh".to_string(), "-c".to_string(), command])
+}
+
+fn shell_quote(value: &str) -> String {
+    if !value.is_empty()
+        && value.chars().all(|ch| {
+            ch.is_ascii_alphanumeric()
+                || matches!(
+                    ch,
+                    '@' | '%' | '_' | '+' | '=' | ':' | ',' | '.' | '/' | '-'
+                )
+        })
+    {
+        return value.to_string();
+    }
+
+    format!("'{}'", value.replace('\'', "'\\''"))
+}
+
 /// Collect the foreground terminal job for a given child PID.
 pub fn foreground_job(child_pid: u32) -> Option<ForegroundJob> {
     let tpgid = foreground_process_group_id(child_pid)?;
@@ -794,4 +818,15 @@ mod tests {
         let _ = std::fs::remove_file(&path);
         assert_eq!(args, "--\n-danger\nbody\n");
     }
+
+    #[test]
+    fn scrollback_editor_argv_preserves_unix_editor_shell_semantics() {
+        let path = std::path::Path::new("/tmp/herdr scrollback.txt");
+        let argv = scrollback_editor_argv(path).unwrap();
+
+        assert_eq!(argv[0], "/bin/sh");
+        assert_eq!(argv[1], "-c");
+        assert!(argv[2].contains("EDITOR:-vi"));
+        assert!(argv[2].contains("/tmp/herdr scrollback.txt"));
+    }
 }

src/platform/macos.rs

@@ -16,6 +16,30 @@ const PROC_PGRP_ONLY: u32 = 2;
 const SERVER_NOFILE_LIMIT_TARGET: libc::rlim_t = 8192;
 const CF_STRING_ENCODING_UTF8: u32 = 0x0800_0100;
 
+pub(crate) fn scrollback_editor_argv(path: &Path) -> std::io::Result<Vec<String>> {
+    let quoted_path = shell_quote(&path.display().to_string());
+    let command = format!(
+        r#"scrollback_file={quoted_path}; eval "${{EDITOR:-vi}} \"\$scrollback_file\""; status=$?; rm -f "$scrollback_file"; exit $status"#
+    );
+    Ok(vec!["/bin/sh".to_string(), "-c".to_string(), command])
+}
+
+fn shell_quote(value: &str) -> String {
+    if !value.is_empty()
+        && value.chars().all(|ch| {
+            ch.is_ascii_alphanumeric()
+                || matches!(
+                    ch,
+                    '@' | '%' | '_' | '+' | '=' | ':' | ',' | '.' | '/' | '-'
+                )
+        })
+    {
+        return value.to_string();
+    }
+
+    format!("'{}'", value.replace('\'', "'\\''"))
+}
+
 #[repr(C)]
 struct TisInputSource {
     _private: [u8; 0],
@@ -1117,4 +1141,15 @@ printf '%s\n' "$@" > "$HERDR_NOTIFY_ARGS"
             "-e\non run argv\n-e\ndisplay notification (item 2 of argv) with title (item 1 of argv)\n-e\nend run\ntitle\nbody\n"
         );
     }
+
+    #[test]
+    fn scrollback_editor_argv_preserves_unix_editor_shell_semantics() {
+        let path = std::path::Path::new("/tmp/herdr scrollback.txt");
+        let argv = scrollback_editor_argv(path).unwrap();
+
+        assert_eq!(argv[0], "/bin/sh");
+        assert_eq!(argv[1], "-c");
+        assert!(argv[2].contains("EDITOR:-vi"));
+        assert!(argv[2].contains("/tmp/herdr scrollback.txt"));
+    }
 }

src/platform/windows.rs

@@ -46,6 +46,41 @@ struct WindowsProcessEntry {
 
 pub fn raise_server_nofile_limit() {}
 
+pub(crate) fn scrollback_editor_argv(path: &std::path::Path) -> std::io::Result<Vec<String>> {
+    let editor = std::env::var("VISUAL")
+        .ok()
+        .filter(|value| !value.trim().is_empty())
+        .or_else(|| {
+            std::env::var("EDITOR")
+                .ok()
+                .filter(|value| !value.trim().is_empty())
+        });
+    scrollback_editor_argv_with_env(path, editor.as_deref())
+}
+
+fn scrollback_editor_argv_with_env(
+    path: &std::path::Path,
+    editor: Option<&str>,
+) -> std::io::Result<Vec<String>> {
+    let mut argv = match editor.filter(|value| !value.trim().is_empty()) {
+        Some(editor) => command_line_to_argv(editor).ok_or_else(|| {
+            std::io::Error::new(
+                std::io::ErrorKind::InvalidInput,
+                format!("failed to parse editor command {editor:?}"),
+            )
+        })?,
+        None => vec!["notepad.exe".to_string()],
+    };
+    if argv.is_empty() {
+        return Err(std::io::Error::new(
+            std::io::ErrorKind::InvalidInput,
+            "editor command must not be empty",
+        ));
+    }
+    argv.push(path.display().to_string());
+    Ok(argv)
+}
+
 pub fn detach_server_daemon_command(_command: &mut std::process::Command) {}
 
 pub fn current_process_is_detached_server_daemon() -> bool {
@@ -698,6 +733,31 @@ mod tests {
         assert_eq!(pids, vec![10, 20, 30]);
     }
 
+    #[test]
+    fn scrollback_editor_argv_uses_editor_env_and_appends_path() {
+        let path = std::path::Path::new(r"C:\Users\User\AppData\Local\Temp\herdr scrollback.txt");
+        let argv = super::scrollback_editor_argv_with_env(
+            path,
+            Some(r#""C:\Program Files\Microsoft VS Code\Code.exe" --wait"#),
+        )
+        .unwrap();
+
+        assert_eq!(argv[0], r"C:\Program Files\Microsoft VS Code\Code.exe");
+        assert_eq!(argv[1], "--wait");
+        assert_eq!(argv[2], path.display().to_string());
+    }
+
+    #[test]
+    fn scrollback_editor_argv_falls_back_to_notepad() {
+        let path = std::path::Path::new(r"C:\Temp\herdr-scrollback.txt");
+        let argv = super::scrollback_editor_argv_with_env(path, None).unwrap();
+
+        assert_eq!(
+            argv,
+            vec!["notepad.exe".to_string(), path.display().to_string()]
+        );
+    }
+
     fn test_entry(
         pid: u32,
         parent_pid: u32,