Gate manual TUI launch input

src/bin/dosh-client.rs

@@ -2844,6 +2844,7 @@ async fn run_terminal(
     let mut pending_user_input: VecDeque<Vec<u8>> = VecDeque::new();
     let mut pending_user_input_bytes = 0usize;
     let mut startup_input_hold_until: Option<Instant> = None;
+    let mut shell_command_line: Vec<u8> = Vec::new();
     if let Some(frame) = first_frame {
         if !forward_only {
             render_frame(&frame)?;
@@ -2920,6 +2921,28 @@ async fn run_terminal(
                                 )
                                 .await?;
                             }
+                            let hold_after_submit = update_shell_command_line(
+                                &mut shell_command_line,
+                                &bytes,
+                                predictor.alternate_screen,
+                            );
+                            if hold_after_submit
+                                && let Some((send_now, hold_for_later)) =
+                                    split_after_command_submit(&bytes)
+                            {
+                                predictor.observe_input(&send_now)?;
+                                send_input(&socket, addr, &cred, &mut send_seq, send_now).await?;
+                                startup_input_hold_until =
+                                    Some(Instant::now() + STARTUP_INPUT_HOLD);
+                                if !hold_for_later.is_empty() {
+                                    queue_pending_user_input(
+                                        &mut pending_user_input,
+                                        &mut pending_user_input_bytes,
+                                        hold_for_later,
+                                    )?;
+                                }
+                                continue;
+                            }
                             if last_packet_at.elapsed() >= Duration::from_secs(2) {
                                 queue_pending_user_input(
                                     &mut pending_user_input,
@@ -3790,6 +3813,81 @@ fn queue_pending_user_input(
     Ok(())
 }
 
+fn split_after_command_submit(bytes: &[u8]) -> Option<(Vec<u8>, Vec<u8>)> {
+    let split_at = bytes
+        .iter()
+        .position(|byte| matches!(byte, b'\r' | b'\n'))?
+        + 1;
+    if split_at == bytes.len() {
+        return Some((bytes.to_vec(), Vec::new()));
+    }
+    let later = bytes[split_at..].to_vec();
+    let now = bytes[..split_at].to_vec();
+    Some((now, later))
+}
+
+fn update_shell_command_line(line: &mut Vec<u8>, bytes: &[u8], alternate_screen: bool) -> bool {
+    if alternate_screen {
+        line.clear();
+        return false;
+    }
+    let mut submitted_tui = false;
+    let mut i = 0;
+    while i < bytes.len() {
+        match bytes[i] {
+            b'\r' | b'\n' => {
+                submitted_tui |= shell_line_starts_tui(line);
+                line.clear();
+                i += 1;
+            }
+            0x08 | 0x7f => {
+                line.pop();
+                i += 1;
+            }
+            0x20..=0x7e => {
+                line.push(bytes[i]);
+                i += 1;
+            }
+            0x1b => {
+                // Cursor editing makes the cheap line model unreliable; drop it
+                // rather than guessing. The command will still run normally.
+                line.clear();
+                i = bytes.len();
+            }
+            _ => {
+                i += 1;
+            }
+        }
+    }
+    submitted_tui
+}
+
+fn shell_line_starts_tui(line: &[u8]) -> bool {
+    let Ok(text) = std::str::from_utf8(line) else {
+        return false;
+    };
+    let command = text
+        .trim_start()
+        .split([' ', '\t', ';', '&', '|'])
+        .next()
+        .unwrap_or("");
+    matches!(
+        command,
+        "tm" | "tmux"
+            | "vim"
+            | "nvim"
+            | "vi"
+            | "less"
+            | "more"
+            | "man"
+            | "top"
+            | "htop"
+            | "btop"
+            | "btm"
+            | "watch"
+    )
+}
+
 async fn flush_pending_user_input(
     socket: &UdpSocket,
     addr: SocketAddr,
@@ -5258,8 +5356,9 @@ mod tests {
         queue_pending_user_input, raw_contains_host_table, recv_response_until,
         render_status_clear, render_status_overlay, requested_env, resolved_startup_command,
         rewrite_forward_command, selected_predict_mode, selected_udp_host, server_version_mismatch,
-        ssh_destination_host, ssh_username, ssh_with_user, startup_command, status_ssh_target,
-        toml_bare_key_or_quoted, update_check_requested, valid_forward_host,
+        split_after_command_submit, ssh_destination_host, ssh_username, ssh_with_user,
+        startup_command, status_ssh_target, toml_bare_key_or_quoted, update_check_requested,
+        update_shell_command_line, valid_forward_host,
     };
     use dosh::config::{ClientConfig, CommandExtension, HostConfig};
     use dosh::native::EnvVar;
@@ -5910,6 +6009,37 @@ mod tests {
         );
     }
 
+    #[test]
+    fn split_after_command_submit_holds_followup_input() {
+        assert_eq!(split_after_command_submit(b"tm"), None);
+        assert_eq!(
+            split_after_command_submit(b"tm\r"),
+            Some((b"tm\r".to_vec(), Vec::new()))
+        );
+        assert_eq!(
+            split_after_command_submit(b"tm\r\x1b[B"),
+            Some((b"tm\r".to_vec(), b"\x1b[B".to_vec()))
+        );
+    }
+
+    #[test]
+    fn shell_command_line_detects_tui_submit() {
+        let mut line = Vec::new();
+        assert!(!update_shell_command_line(&mut line, b"echo ok\r", false));
+        assert!(line.is_empty());
+
+        assert!(!update_shell_command_line(&mut line, b"t", false));
+        assert!(!update_shell_command_line(&mut line, b"m", false));
+        assert!(update_shell_command_line(&mut line, b"\r", false));
+        assert!(line.is_empty());
+
+        assert!(update_shell_command_line(
+            &mut line,
+            b"  btop\r\x1b[B",
+            false
+        ));
+    }
+
     #[test]
     fn update_check_accepts_only_check_flag() {
         assert!(!update_check_requested(&[]).unwrap());