fix: report truncated pane reads

refs #1717

1 files changed, 98 insertions, 38 deletions

diff --git a/src/pane/terminal.rs b/src/pane/terminal.rs
index 81c57ef9..d5070b9b 100644
--- a/src/pane/terminal.rs
+++ b/src/pane/terminal.rs
@@ -141,6 +141,12 @@ pub(crate) struct ProcessBytesResult {
     pub terminal_responses: Vec<Bytes>,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Default)]
+pub(crate) struct TerminalReadSnapshot {
+    pub text: String,
+    pub truncated: bool,
+}
+
 pub(crate) struct GhosttyPaneTerminal {
     pub core: Mutex<GhosttyPaneCore>,
     key_encoder: Mutex<crate::ghostty::KeyEncoder>,
@@ -387,18 +393,26 @@ impl PaneTerminal {
         self.ghostty.recent_text(lines)
     }
 
-    pub fn recent_ansi(&self, lines: usize) -> String {
-        self.ghostty.recent_ansi(lines)
+    pub(crate) fn recent_text_snapshot(&self, lines: usize) -> TerminalReadSnapshot {
+        self.ghostty.recent_text_snapshot(lines)
     }
 
-    pub fn recent_unwrapped_text(&self, lines: usize) -> String {
-        self.ghostty.recent_unwrapped_text(lines)
+    pub(crate) fn recent_ansi_snapshot(&self, lines: usize) -> TerminalReadSnapshot {
+        self.ghostty.recent_ansi_snapshot(lines)
+    }
+
+    pub(crate) fn recent_unwrapped_text_snapshot(&self, lines: usize) -> TerminalReadSnapshot {
+        self.ghostty.recent_unwrapped_text_snapshot(lines)
     }
 
     pub fn recent_unwrapped_ansi(&self, lines: usize) -> String {
         self.ghostty.recent_unwrapped_ansi(lines)
     }
 
+    pub(crate) fn recent_unwrapped_ansi_snapshot(&self, lines: usize) -> TerminalReadSnapshot {
+        self.ghostty.recent_unwrapped_ansi_snapshot(lines)
+    }
+
     pub fn extract_selection(&self, selection: &crate::selection::Selection) -> Option<String> {
         self.ghostty.extract_selection(selection)
     }
@@ -1708,34 +1722,52 @@ impl GhosttyPaneTerminal {
     }
 
     pub fn recent_text(&self, lines: usize) -> String {
+        self.recent_text_snapshot(lines).text
+    }
+
+    pub(crate) fn recent_text_snapshot(&self, lines: usize) -> TerminalReadSnapshot {
         self.core
             .lock()
             .ok()
-            .and_then(|core| ghostty_recent_text(&core, lines).ok())
+            .and_then(|core| ghostty_recent_text_snapshot(&core, lines).ok())
             .unwrap_or_default()
     }
 
+    #[cfg(test)]
     pub fn recent_ansi(&self, lines: usize) -> String {
+        self.recent_ansi_snapshot(lines).text
+    }
+
+    pub(crate) fn recent_ansi_snapshot(&self, lines: usize) -> TerminalReadSnapshot {
         self.core
             .lock()
             .ok()
-            .and_then(|core| ghostty_recent_ansi(&core, lines, false).ok())
+            .and_then(|core| ghostty_recent_ansi_snapshot(&core, lines, false).ok())
             .unwrap_or_default()
     }
 
+    #[cfg(test)]
     pub fn recent_unwrapped_text(&self, lines: usize) -> String {
+        self.recent_unwrapped_text_snapshot(lines).text
+    }
+
+    pub(crate) fn recent_unwrapped_text_snapshot(&self, lines: usize) -> TerminalReadSnapshot {
         self.core
             .lock()
             .ok()
-            .and_then(|core| ghostty_recent_text_unwrapped(&core, lines).ok())
+            .and_then(|core| ghostty_recent_text_unwrapped_snapshot(&core, lines).ok())
             .unwrap_or_default()
     }
 
     pub fn recent_unwrapped_ansi(&self, lines: usize) -> String {
+        self.recent_unwrapped_ansi_snapshot(lines).text
+    }
+
+    pub(crate) fn recent_unwrapped_ansi_snapshot(&self, lines: usize) -> TerminalReadSnapshot {
         self.core
             .lock()
             .ok()
-            .and_then(|core| ghostty_recent_ansi(&core, lines, true).ok())
+            .and_then(|core| ghostty_recent_ansi_snapshot(&core, lines, true).ok())
             .unwrap_or_default()
     }
 
@@ -2289,34 +2321,23 @@ fn ghostty_recent_text(
     core: &GhosttyPaneCore,
     lines: usize,
 ) -> Result<String, crate::ghostty::Error> {
+    ghostty_recent_text_snapshot(core, lines).map(|snapshot| snapshot.text)
+}
+
+fn ghostty_recent_text_snapshot(
+    core: &GhosttyPaneCore,
+    lines: usize,
+) -> Result<TerminalReadSnapshot, crate::ghostty::Error> {
     let text = ghostty_recent_text_for_terminal(&core.terminal, lines)?;
-    #[cfg(windows)]
-    {
-        if text.trim().is_empty() {
-            let fallback = windows_recent_fallback::recent_text(core, lines, false);
-            if !fallback.trim().is_empty() {
-                return Ok(fallback);
-            }
-        }
-    }
-    Ok(text)
+    Ok(finish_recent_snapshot(core, text, lines, false))
 }
 
-fn ghostty_recent_text_unwrapped(
+fn ghostty_recent_text_unwrapped_snapshot(
     core: &GhosttyPaneCore,
     lines: usize,
-) -> Result<String, crate::ghostty::Error> {
+) -> Result<TerminalReadSnapshot, crate::ghostty::Error> {
     let text = ghostty_recent_text_unwrapped_for_terminal(&core.terminal, lines)?;
-    #[cfg(windows)]
-    {
-        if text.trim().is_empty() {
-            let fallback = windows_recent_fallback::recent_text(core, lines, true);
-            if !fallback.trim().is_empty() {
-                return Ok(fallback);
-            }
-        }
-    }
-    Ok(text)
+    Ok(finish_recent_snapshot(core, text, lines, true))
 }
 
 fn ghostty_recent_ansi(
@@ -2324,17 +2345,42 @@ fn ghostty_recent_ansi(
     lines: usize,
     unwrap: bool,
 ) -> Result<String, crate::ghostty::Error> {
-    let ansi = ghostty_recent_ansi_for_terminal(&core.terminal, lines, unwrap)?;
+    ghostty_recent_ansi_snapshot(core, lines, unwrap).map(|snapshot| snapshot.text)
+}
+
+fn ghostty_recent_ansi_snapshot(
+    core: &GhosttyPaneCore,
+    lines: usize,
+    unwrap: bool,
+) -> Result<TerminalReadSnapshot, crate::ghostty::Error> {
+    let text = ghostty_recent_ansi_for_terminal(&core.terminal, lines, unwrap)?;
+    Ok(finish_recent_snapshot(core, text, lines, unwrap))
+}
+
+fn finish_recent_snapshot(
+    core: &GhosttyPaneCore,
+    text: String,
+    lines: usize,
+    unwrap: bool,
+) -> TerminalReadSnapshot {
+    #[cfg(not(windows))]
+    let _ = unwrap;
     #[cfg(windows)]
-    {
-        if ansi.trim().is_empty() {
-            let fallback = windows_recent_fallback::recent_text(core, lines, unwrap);
-            if !fallback.trim().is_empty() {
-                return Ok(fallback);
-            }
+    if text.trim().is_empty() {
+        let fallback = windows_recent_fallback::recent_text(core, lines, unwrap);
+        if !fallback.text.trim().is_empty() {
+            return fallback;
         }
     }
-    Ok(ansi)
+
+    // Recent read limits are measured in rendered rows, including blank or styled rows.
+    TerminalReadSnapshot {
+        text,
+        truncated: core
+            .terminal
+            .total_rows()
+            .is_ok_and(|total_rows| total_rows > lines),
+    }
 }
 
 fn ghostty_recent_text_for_terminal(
@@ -4342,6 +4388,20 @@ mod tests {
     }
 
     #[test]
+    fn recent_snapshots_report_omitted_rendered_rows() {
+        let (tx, _rx) = mpsc::channel(4);
+        let mut terminal = crate::ghostty::Terminal::new(20, 3, 100).unwrap();
+        terminal.write(b"one\r\ntwo\r\nthree\r\nfour");
+        let pane = GhosttyPaneTerminal::new(terminal, tx).unwrap();
+
+        assert!(pane.recent_text_snapshot(2).truncated);
+        assert!(pane.recent_ansi_snapshot(2).truncated);
+        assert!(pane.recent_unwrapped_text_snapshot(2).truncated);
+        assert!(pane.recent_unwrapped_ansi_snapshot(2).truncated);
+        assert!(!pane.recent_text_snapshot(100).truncated);
+    }
+
+    #[test]
     fn plain_text_reads_skip_wide_character_spacer_cells() {
         let (tx, _rx) = mpsc::channel(4);
         let mut terminal = crate::ghostty::Terminal::new(40, 3, 100).unwrap();