perf: adopt libghostty integration improvements

refs #276

2 files changed, 100 insertions, 133 deletions

diff --git a/src/pane/osc.rs b/src/pane/osc.rs
index f7cf9eb9..22e76ff1 100644
--- a/src/pane/osc.rs
+++ b/src/pane/osc.rs
@@ -396,84 +396,13 @@ impl Osc52Forwarder {
     }
 }
 
-/// Reconstructs cwd-reporting OSC sequences from child output. Shell
-/// integrations commonly use OSC 7 (`file://...`), while Windows Terminal
-/// documents OSC 9;9 for the same practical purpose.
-#[derive(Debug, Default)]
-pub(super) struct CwdOscTracker {
-    state: Osc52ForwarderState,
-    body: Vec<u8>,
-    pending: Vec<PathBuf>,
-}
-
-impl CwdOscTracker {
-    pub(super) fn observe(&mut self, bytes: &[u8]) {
-        for &byte in bytes {
-            match self.state {
-                Osc52ForwarderState::Ground => {
-                    if byte == 0x1b {
-                        self.state = Osc52ForwarderState::Escape;
-                    }
-                }
-                Osc52ForwarderState::Escape => {
-                    if byte == b']' {
-                        self.body.clear();
-                        self.state = Osc52ForwarderState::OscBody;
-                    } else if byte == 0x1b {
-                        self.state = Osc52ForwarderState::Escape;
-                    } else {
-                        self.state = Osc52ForwarderState::Ground;
-                    }
-                }
-                Osc52ForwarderState::OscBody => match byte {
-                    0x07 => {
-                        self.finalize();
-                        self.state = Osc52ForwarderState::Ground;
-                    }
-                    0x1b => self.state = Osc52ForwarderState::OscEscape,
-                    _ => self.body.push(byte),
-                },
-                Osc52ForwarderState::OscEscape => {
-                    if byte == b'\\' {
-                        self.finalize();
-                        self.state = Osc52ForwarderState::Ground;
-                    } else {
-                        self.body.push(0x1b);
-                        self.body.push(byte);
-                        self.state = Osc52ForwarderState::OscBody;
-                    }
-                }
-            }
-
-            if self.body.len() > 4096 {
-                self.body.clear();
-                self.state = Osc52ForwarderState::Ground;
-            }
-        }
-    }
-
-    fn finalize(&mut self) {
-        if let Some(cwd) = parse_cwd_osc(&self.body) {
-            self.pending.push(cwd);
-        }
-        self.body.clear();
-    }
-
-    pub(super) fn drain_latest(&mut self) -> Option<PathBuf> {
-        self.pending.drain(..).next_back()
+pub(super) fn parse_reported_cwd(value: &[u8]) -> Option<PathBuf> {
+    let value = std::str::from_utf8(value).ok()?.trim();
+    if value.starts_with("file://") {
+        return parse_file_uri_cwd(value);
     }
-}
-
-fn parse_cwd_osc(body: &[u8]) -> Option<PathBuf> {
-    let body = std::str::from_utf8(body).ok()?;
-    if let Some(uri) = body.strip_prefix("7;") {
-        return parse_file_uri_cwd(uri);
-    }
-    if let Some(path) = body.strip_prefix("9;9;") {
-        let path = path.trim().trim_matches('"');
-        return (!path.is_empty()).then(|| PathBuf::from(path));
-    }
-    None
+    let path = value.trim_matches('"');
+    (!path.is_empty()).then(|| PathBuf::from(path))
 }
 
 /// Maximum retained string length for agent OSC title and progress payloads.
@@ -1077,46 +1006,28 @@ mod tests {
     }
 
     #[test]
-    fn cwd_osc_tracker_detects_split_osc7_sequence() {
-        let mut tracker = CwdOscTracker::default();
-
-        tracker.observe(b"\x1b]7;file:///tmp/herdr%20repo");
-        assert_eq!(tracker.drain_latest(), None);
-        tracker.observe(b"\x07");
-
+    fn reported_cwd_parses_file_uri_and_bare_paths() {
         assert_eq!(
-            tracker.drain_latest(),
+            parse_reported_cwd(b"file:///tmp/herdr%20repo"),
             Some(std::path::PathBuf::from("/tmp/herdr repo"))
         );
-    }
-
-    #[test]
-    fn cwd_osc_tracker_detects_windows_terminal_cwd_sequence() {
-        let mut tracker = CwdOscTracker::default();
-
-        tracker.observe(b"\x1b]9;9;C:\\Users\\herdr\\src\\herdr\x1b\\");
-
         assert_eq!(
-            tracker.drain_latest(),
+            parse_reported_cwd(b"C:\\Users\\herdr\\src\\herdr"),
             Some(std::path::PathBuf::from("C:\\Users\\herdr\\src\\herdr"))
         );
-    }
-
-    // The quoted form is what Windows Terminal's documented shell integration
-    // snippet emits. Herdr's own injected prompt integration deliberately
-    // emits the path unquoted; see WINDOWS_POWERSHELL_SHELL_INTEGRATION_COMMAND.
-    #[test]
-    fn cwd_osc_tracker_detects_quoted_powershell_prompt_cwd_sequence() {
-        let mut tracker = CwdOscTracker::default();
-
-        tracker.observe(b"PS C:\\my proj> \x1b]9;9;\"C:\\my proj\"\x1b\\");
-
         assert_eq!(
-            tracker.drain_latest(),
+            parse_reported_cwd(b"\"C:\\my proj\""),
             Some(std::path::PathBuf::from("C:\\my proj"))
         );
     }
 
+    #[test]
+    fn reported_cwd_rejects_invalid_or_empty_values() {
+        assert_eq!(parse_reported_cwd(b""), None);
+        assert_eq!(parse_reported_cwd(b"\xff"), None);
+        assert_eq!(parse_reported_cwd(b"file://remote/tmp"), None);
+    }
+
     // -----------------------------------------------------------------------
     // AgentOscStateTracker tests
     // -----------------------------------------------------------------------
diff --git a/src/pane/terminal.rs b/src/pane/terminal.rs
index cf7a82f4..8e33b1b3 100644
--- a/src/pane/terminal.rs
+++ b/src/pane/terminal.rs
@@ -28,10 +28,10 @@ use super::{
     kitty_keyboard::KittyKeyboardTracker,
     osc::{
         contains_scrollback_clear_sequence, current_transient_default_color_owner,
-        maybe_filter_primary_screen_scrollback_clear, restore_host_terminal_theme_if_needed,
-        write_host_terminal_theme_selective, AgentOscStateTracker, CwdOscTracker,
-        DefaultColorEvent, DefaultColorEventTracker, DefaultColorOscTracker, DefaultColorQuery,
-        DefaultColorTrackedEvent, Osc52Forwarder, OscDebugTracker,
+        maybe_filter_primary_screen_scrollback_clear, parse_reported_cwd,
+        restore_host_terminal_theme_if_needed, write_host_terminal_theme_selective,
+        AgentOscStateTracker, DefaultColorEvent, DefaultColorEventTracker, DefaultColorOscTracker,
+        DefaultColorQuery, DefaultColorTrackedEvent, Osc52Forwarder, OscDebugTracker,
     },
     xtgettcap::{XtgettcapQueryTracker, XtgettcapResponse},
 };
@@ -162,7 +162,6 @@ pub(crate) struct GhosttyPaneCore {
     pub child_default_foreground_changed: bool,
     pub child_default_background_changed: bool,
     pub osc52_forwarder: Osc52Forwarder,
-    pub cwd_osc_tracker: CwdOscTracker,
     pub osc_debug_tracker: OscDebugTracker,
     pub agent_osc_state: AgentOscStateTracker,
     pub xtgettcap_query_tracker: XtgettcapQueryTracker,
@@ -917,7 +916,6 @@ impl GhosttyPaneTerminal {
                 child_default_foreground_changed: false,
                 child_default_background_changed: false,
                 osc52_forwarder: Osc52Forwarder::default(),
-                cwd_osc_tracker: CwdOscTracker::default(),
                 osc_debug_tracker: OscDebugTracker::default(),
                 agent_osc_state: AgentOscStateTracker::default(),
                 xtgettcap_query_tracker: XtgettcapQueryTracker::default(),
@@ -1050,6 +1048,7 @@ impl GhosttyPaneTerminal {
             };
         };
 
+        let _ = core.terminal.take_pwd_changes();
         let default_color_observation = core.default_color_tracker.observe(bytes);
         if shell_pid > 0 && default_color_observation {
             if let Some(owner_pgid) = current_transient_default_color_owner(shell_pid) {
@@ -1063,8 +1062,6 @@ impl GhosttyPaneTerminal {
 
         core.osc52_forwarder.observe(bytes);
         let clipboard_writes = core.osc52_forwarder.drain_pending();
-        core.cwd_osc_tracker.observe(bytes);
-        let reported_cwd = core.cwd_osc_tracker.drain_latest();
         core.osc_debug_tracker.observe(bytes);
         for event in core.osc_debug_tracker.drain_pending() {
             debug!(
@@ -1119,6 +1116,12 @@ impl GhosttyPaneTerminal {
             xtgettcap_responses,
             &mut terminal_responses,
         );
+        let reported_cwd = core
+            .terminal
+            .take_pwd_changes()
+            .into_iter()
+            .filter_map(|value| parse_reported_cwd(&value))
+            .next_back();
         #[cfg(windows)]
         windows_recent_fallback::update(&mut core);
         crate::render_prof::duration_since("pty.ghostty_write", write_started);
@@ -1406,7 +1409,7 @@ impl GhosttyPaneTerminal {
                     core.terminal.write(ansi.as_bytes());
                 }
             }
-            ghostty_restore_scroll_offset_from_bottom(&mut core.terminal, offset_from_bottom);
+            ghostty_set_scroll_offset_from_bottom(&mut core.terminal, offset_from_bottom);
             if offset_from_bottom > 0 {
                 let mut remaining = offset_from_bottom.min(resize_recovery_probe_lines);
                 while remaining > 0
@@ -1444,10 +1447,7 @@ impl GhosttyPaneTerminal {
 
     pub fn set_scroll_offset_from_bottom(&self, lines: usize) {
         if let Ok(mut core) = self.core.lock() {
-            core.terminal.scroll_viewport_bottom();
-            if lines > 0 {
-                core.terminal.scroll_viewport_delta(-(lines as isize));
-            }
+            ghostty_set_scroll_offset_from_bottom(&mut core.terminal, lines);
         }
     }
 
@@ -2381,22 +2381,16 @@ fn ghostty_recent_read_range(
     Ok(Some((start, end, cols)))
 }
 
-fn ghostty_restore_scroll_offset_from_bottom(
+fn ghostty_set_scroll_offset_from_bottom(
     terminal: &mut crate::ghostty::Terminal,
     offset_from_bottom: usize,
 ) {
-    terminal.scroll_viewport_bottom();
-    if offset_from_bottom == 0 {
-        return;
-    }
     let Ok(scrollbar) = terminal.scrollbar() else {
+        terminal.scroll_viewport_bottom();
         return;
     };
     let max_offset = scrollbar.total.saturating_sub(scrollbar.len);
-    let offset = offset_from_bottom.min(max_offset).min(isize::MAX as usize) as isize;
-    if offset > 0 {
-        terminal.scroll_viewport_delta(-offset);
-    }
+    terminal.scroll_viewport_row(max_offset.saturating_sub(offset_from_bottom));
 }
 
 fn ghostty_extract_selection(
@@ -3188,6 +3182,52 @@ mod tests {
         Bytes::from(format!("\x1b]{command};rgb:{r:04x}/{g:04x}/{b:04x}\x1b\\"))
     }
 
+    #[test]
+    fn process_pty_bytes_reports_latest_libghostty_pwd_callback() {
+        let (tx, _rx) = mpsc::channel(4);
+        let terminal = crate::ghostty::Terminal::new(80, 24, 100).unwrap();
+        let pane = GhosttyPaneTerminal::new(terminal, tx.clone()).unwrap();
+        let pane_id = PaneId::from_raw(1);
+
+        let partial = pane.process_pty_bytes(pane_id, 0, b"\x1b]7;file:///tmp/herdr%20", &tx);
+        assert_eq!(partial.reported_cwd, None);
+
+        let completed = pane.process_pty_bytes(pane_id, 0, b"repo\x07", &tx);
+        #[cfg(not(windows))]
+        assert_eq!(
+            completed.reported_cwd,
+            Some(std::path::PathBuf::from("/tmp/herdr repo"))
+        );
+        #[cfg(windows)]
+        assert_eq!(
+            completed.reported_cwd,
+            Some(std::path::PathBuf::from("\\tmp\\herdr repo"))
+        );
+
+        let latest = pane.process_pty_bytes(
+            pane_id,
+            0,
+            b"\x1b]9;9;/tmp/conemu\x1b\\\x1b]1337;CurrentDir=/tmp/iterm2\x1b\\",
+            &tx,
+        );
+        assert_eq!(
+            latest.reported_cwd,
+            Some(std::path::PathBuf::from("/tmp/iterm2"))
+        );
+    }
+
+    #[test]
+    fn seeded_history_pwd_does_not_leak_into_live_output() {
+        let (tx, _rx) = mpsc::channel(4);
+        let terminal = crate::ghostty::Terminal::new(80, 24, 100).unwrap();
+        let pane = GhosttyPaneTerminal::new(terminal, tx.clone()).unwrap();
+        pane.seed_history_ansi("\x1b]7;file:///tmp/restored\x07");
+
+        let result = pane.process_pty_bytes(PaneId::from_raw(1), 0, b"live output", &tx);
+
+        assert_eq!(result.reported_cwd, None);
+    }
+
     #[cfg(windows)]
     #[test]
     fn windows_powershell_prompt_cwd_uses_latest_default_prompt_path() {
@@ -4125,7 +4165,7 @@ mod tests {
     }
 
     #[test]
-    fn pane_scrollback_controls_reach_top_without_ui_interference() {
+    fn pane_scrollback_controls_round_trip_and_clamp_without_ui_interference() {
         let (tx, _rx) = mpsc::channel(4);
         let mut terminal = crate::ghostty::Terminal::new(80, 3, 100).unwrap();
         write_numbered_lines(&mut terminal, 1000);
@@ -4135,10 +4175,20 @@ mod tests {
         assert!(before.max_offset_from_bottom > 0);
         assert_eq!(before.offset_from_bottom, 0);
 
-        pane.set_scroll_offset_from_bottom(before.max_offset_from_bottom);
+        for offset in [
+            0,
+            before.max_offset_from_bottom / 2,
+            before.max_offset_from_bottom,
+            usize::MAX,
+        ] {
+            pane.set_scroll_offset_from_bottom(offset);
+            let after = pane.scroll_metrics().expect("scroll metrics after scroll");
+            assert_eq!(
+                after.offset_from_bottom,
+                offset.min(after.max_offset_from_bottom)
+            );
+        }
 
-        let after = pane.scroll_metrics().expect("scroll metrics after scroll");
-        assert_eq!(after.offset_from_bottom, after.max_offset_from_bottom);
         assert!(pane.visible_text().contains("000000"));
     }
 
@@ -4270,11 +4320,17 @@ mod tests {
         assert!(!pane.visible_text().trim().is_empty());
 
         for (rows, cols) in [(4, 10), (4, 7), (6, 18), (3, 9), (5, 12)] {
+            let before_resize = pane.scroll_metrics().expect("scroll metrics before resize");
             pane.resize(rows, cols, 0, 0);
 
             let metrics = pane.scroll_metrics().expect("scroll metrics after resize");
             assert_eq!(metrics.viewport_rows, rows as usize);
-            assert!(metrics.offset_from_bottom <= metrics.max_offset_from_bottom);
+            assert_eq!(
+                metrics.offset_from_bottom,
+                before_resize
+                    .offset_from_bottom
+                    .min(metrics.max_offset_from_bottom)
+            );
             assert!(
                 metrics.offset_from_bottom > 0,
                 "resize should preserve a scrolled viewport instead of jumping to bottom"