fix: include short viewport output in recent reads (#3448)

refs #3444

Co-authored-by: akbash-bot <300245827+akbash-bot@users.noreply.github.com>

2 files changed, 56 insertions, 1 deletions

diff --git a/src/ghostty/mod.rs b/src/ghostty/mod.rs
index c044d3b0..261638af 100644
--- a/src/ghostty/mod.rs
+++ b/src/ghostty/mod.rs
@@ -1412,6 +1412,10 @@ impl Terminal {
         self.get_u16(ffi::GhosttyTerminalData_GHOSTTY_TERMINAL_DATA_ROWS)
     }
 
+    pub fn cursor_y(&self) -> Result<u16, Error> {
+        self.get_u16(ffi::GhosttyTerminalData_GHOSTTY_TERMINAL_DATA_CURSOR_Y)
+    }
+
     pub fn effective_foreground_color(&self) -> Result<Option<RgbColor>, Error> {
         self.get_optional_rgb_color(TERMINAL_DATA_COLOR_FOREGROUND)
     }
diff --git a/src/pane/terminal.rs b/src/pane/terminal.rs
index df84e5cb..154a9539 100644
--- a/src/pane/terminal.rs
+++ b/src/pane/terminal.rs
@@ -2807,7 +2807,34 @@ fn ghostty_recent_read_range(
     if total_rows == 0 || cols == 0 || lines == 0 {
         return Ok(None);
     }
-    let end = total_rows.saturating_sub(1);
+
+    let physical_end = total_rows.saturating_sub(1);
+    if terminal.active_screen()? != crate::ghostty::ActiveScreen::Primary {
+        let start = physical_end.saturating_add(1).saturating_sub(lines);
+        return Ok(Some((start, physical_end, cols)));
+    }
+
+    let rows = usize::from(terminal.rows()?);
+    if rows == 0 {
+        return Ok(None);
+    }
+    let viewport_start = total_rows.saturating_sub(rows);
+    let cursor_row = viewport_start
+        .saturating_add(usize::from(terminal.cursor_y()?))
+        .min(total_rows.saturating_sub(1));
+    let mut last_content_row = None;
+    for row in (viewport_start..total_rows).rev() {
+        if !ghostty_screen_row(terminal, cols, row as u32)?
+            .trim()
+            .is_empty()
+        {
+            last_content_row = Some(row);
+            break;
+        }
+    }
+    let end = last_content_row
+        .map(|row| row.max(cursor_row))
+        .unwrap_or_else(|| total_rows.saturating_sub(1));
     let start = end.saturating_add(1).saturating_sub(lines);
     Ok(Some((start, end, cols)))
 }
@@ -5243,6 +5270,30 @@ mod tests {
     }
 
     #[test]
+    fn recent_reads_include_viewport_before_scrollback_exists() {
+        let (tx, _rx) = mpsc::channel(4);
+        let mut terminal =
+            crate::ghostty::Terminal::new(20, 20, crate::config::DEFAULT_SCROLLBACK_LIMIT_BYTES)
+                .unwrap();
+        terminal.write(b"hello123");
+        let pane = GhosttyPaneTerminal::new(terminal, tx).unwrap();
+
+        assert_eq!(pane.recent_text(3), "hello123\n");
+        assert_eq!(pane.recent_unwrapped_text(3), "hello123");
+    }
+
+    #[test]
+    fn alternate_screen_recent_reads_keep_physical_row_ranges() {
+        let (tx, _rx) = mpsc::channel(4);
+        let mut terminal = crate::ghostty::Terminal::new(20, 20, 100).unwrap();
+        terminal.write(b"\x1b[?1049hhello123");
+        let pane = GhosttyPaneTerminal::new(terminal, tx).unwrap();
+
+        assert_eq!(pane.recent_text(3), "");
+        assert_eq!(pane.recent_unwrapped_text(3), "");
+    }
+
+    #[test]
     fn recent_unwrapped_text_ignores_soft_wraps() {
         let (tx, _rx) = mpsc::channel(4);
         let mut terminal = crate::ghostty::Terminal::new(5, 3, 100).unwrap();