From 3f7236f81735e338e2ed3ecbf0f1fed26392acba Mon Sep 17 00:00:00 2001
From: Ogulcan Celik <ogulcancelik@gmail.com>
Date: Sun, 7 Jun 2026 17:01:27 +0300
Subject: [PATCH] fix: drop empty pty mouse writes

refs #496
---
 src/pane/terminal.rs  | 32 +++++++++++++++++++++++++---
 src/pty/actor/unix.rs | 49 ++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 75 insertions(+), 6 deletions(-)

diff --git a/src/pane/terminal.rs b/src/pane/terminal.rs
index 9bfcf57f..5f44854d 100644
--- a/src/pane/terminal.rs
+++ b/src/pane/terminal.rs
@@ -923,7 +923,10 @@ impl GhosttyPaneTerminal {
         };
         let mut encoder = ghostty_mouse_encoder_for_terminal(&core.terminal)?;
         let event = ghostty_mouse_event_from_button_kind(kind, column, row, modifiers)?;
-        encoder.encode(&event).ok()
+        encoder
+            .encode(&event)
+            .ok()
+            .filter(|bytes| !bytes.is_empty())
     }
 
     pub fn encode_mouse_motion(
@@ -941,7 +944,10 @@ impl GhosttyPaneTerminal {
         }
         let mut encoder = ghostty_mouse_encoder_for_terminal(&core.terminal)?;
         let event = ghostty_mouse_event_from_motion_kind(kind, column, row, modifiers)?;
-        encoder.encode(&event).ok()
+        encoder
+            .encode(&event)
+            .ok()
+            .filter(|bytes| !bytes.is_empty())
     }
 
     pub fn encode_mouse_wheel(
@@ -956,7 +962,10 @@ impl GhosttyPaneTerminal {
         };
         let mut encoder = ghostty_mouse_encoder_for_terminal(&core.terminal)?;
         let event = ghostty_mouse_event_from_wheel_kind(kind, column, row, modifiers)?;
-        encoder.encode(&event).ok()
+        encoder
+            .encode(&event)
+            .ok()
+            .filter(|bytes| !bytes.is_empty())
     }
 
     pub fn visible_text(&self) -> String {
@@ -2410,6 +2419,23 @@ mod tests {
         assert_eq!(encoded.as_deref(), Some(&b"\x1b[<36;5;7M"[..]));
     }
 
+    #[test]
+    fn ghostty_mouse_drag_without_motion_reporting_is_not_forwarded() {
+        let (tx, _rx) = mpsc::channel(4);
+        let mut terminal = crate::ghostty::Terminal::new(80, 24, 0).unwrap();
+        terminal.write(b"\x1b[?1000h\x1b[?1006h");
+        let pane = GhosttyPaneTerminal::new(terminal, tx).unwrap();
+
+        let encoded = pane.encode_mouse_button(
+            crossterm::event::MouseEventKind::Drag(crossterm::event::MouseButton::Left),
+            4,
+            6,
+            crossterm::event::KeyModifiers::empty(),
+        );
+
+        assert_eq!(encoded, None);
+    }
+
     #[test]
     fn ghostty_mouse_moved_encoding_uses_any_motion_state() {
         let (tx, _rx) = mpsc::channel(4);
diff --git a/src/pty/actor/unix.rs b/src/pty/actor/unix.rs
index 70634475..e25d3dcb 100644
--- a/src/pty/actor/unix.rs
+++ b/src/pty/actor/unix.rs
@@ -408,6 +408,12 @@ struct PtyIoActorRunner {
 }
 
 impl PtyIoActorRunner {
+    fn enqueue_write(&mut self, bytes: Bytes) {
+        if !bytes.is_empty() {
+            self.pending_writes.push_back(bytes);
+        }
+    }
+
     fn run(&mut self) {
         let mut should_exit = false;
         while !should_exit {
@@ -515,7 +521,7 @@ impl PtyIoActorRunner {
         match command {
             PtyIoDataCommand::WriteUserInput(bytes) => {
                 if self.state == ActorState::Running {
-                    self.pending_writes.push_back(bytes);
+                    self.enqueue_write(bytes);
                 }
             }
         }
@@ -592,7 +598,7 @@ impl PtyIoActorRunner {
     fn drain_pre_quiesce_commands(&mut self) {
         while let Ok(PtyIoDataCommand::WriteUserInput(bytes)) = self.data_rx.try_recv() {
             if self.state != ActorState::Released {
-                self.pending_writes.push_back(bytes);
+                self.enqueue_write(bytes);
             }
         }
     }
@@ -639,7 +645,9 @@ impl PtyIoActorRunner {
         if self.state == ActorState::Released {
             return;
         }
-        self.pending_writes.extend(terminal_responses);
+        for bytes in terminal_responses {
+            self.enqueue_write(bytes);
+        }
     }
 
     fn flush_pending_writes_once(&mut self) {
@@ -789,6 +797,41 @@ mod tests {
         (handle, peer, read_rx)
     }
 
+    fn actor_runner_for_unit_test() -> (PtyIoActorRunner, UnixStream) {
+        let (actor_socket, peer) = UnixStream::pair().expect("socket pair");
+        actor_socket
+            .set_nonblocking(true)
+            .expect("actor socket nonblocking");
+        let owned = unsafe { OwnedFd::from_raw_fd(actor_socket.into_raw_fd()) };
+        let (_data_tx, data_rx) = mpsc::channel(ACTOR_COMMAND_BUFFER);
+        let (_control_tx, control_rx) = std_mpsc::channel();
+        let wake_pipe = fd::create_wake_pipe().expect("wake pipe");
+        let runner = PtyIoActorRunner {
+            pane_id: 1,
+            file: std::fs::File::from(owned),
+            data_rx,
+            control_rx,
+            state: ActorState::Running,
+            pending_writes: VecDeque::new(),
+            current_write_offset: 0,
+            wake_read_fd: wake_pipe.read_fd,
+            controls: Arc::new(Mutex::new(SharedPtyControls::default())),
+            on_read: Box::new(|_| PtyReadResult::empty()),
+            on_reader_exit: None,
+            poll_observer: None,
+        };
+        (runner, peer)
+    }
+
+    #[test]
+    fn actor_ignores_empty_user_input_write() {
+        let (mut runner, _peer) = actor_runner_for_unit_test();
+
+        assert!(!runner.handle_data_command(PtyIoDataCommand::WriteUserInput(Bytes::new())));
+
+        assert!(runner.pending_writes.is_empty());
+    }
+
     #[test]
     fn actor_writes_user_input_to_owned_fd() {
         let (handle, mut peer, _read_rx) = actor_with_socket_pair(false);