fix: open scrollback editor on windows without sh

refs #914

4 files changed, 138 insertions, 0 deletions

diff --git a/src/platform/fallback.rs b/src/platform/fallback.rs
index 25bc761c..e9134a8b 100644
--- a/src/platform/fallback.rs
+++ b/src/platform/fallback.rs
@@ -7,6 +7,14 @@ use super::{ClipboardImage, ForegroundJob, Signal};
 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) {}
 
 /// Unsupported platform stub.
diff --git a/src/platform/linux.rs b/src/platform/linux.rs
index 3cf643e5..539c0d93 100644
--- a/src/platform/linux.rs
+++ b/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"));
+    }
 }
diff --git a/src/platform/macos.rs b/src/platform/macos.rs
index df957652..3770a3be 100644
--- a/src/platform/macos.rs
+++ b/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"));
+    }
 }
diff --git a/src/platform/windows.rs b/src/platform/windows.rs
index e7a77e35..50e0e905 100644
--- a/src/platform/windows.rs
+++ b/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,