Fix hint highlight invalidation

This fixes a couple issues with hint highlight invalidation, which would
cause hints to lose their underline highlight despite the terminal
itself not having changed since the highlight started.

Closes #8270.

3 files changed, 35 insertions, 11 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2b3d2b46..095d5fd7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 Notable changes to the `alacritty_terminal` crate are documented in its
 [CHANGELOG](./alacritty_terminal/CHANGELOG.md).
 
+## 0.15.0-dev
+
+### Fixed
+
+- Mouse/Vi cursor hint highlighting broken on the terminal cursor line
+
 ## 0.14.0
 
 ### Packaging
diff --git a/alacritty/src/display/damage.rs b/alacritty/src/display/damage.rs
index 8efe0133..fc6aef39 100644
--- a/alacritty/src/display/damage.rs
+++ b/alacritty/src/display/damage.rs
@@ -193,9 +193,11 @@ impl FrameDamage {
     /// Check if a range is damaged.
     #[inline]
     pub fn intersects(&self, start: Point<usize>, end: Point<usize>) -> bool {
+        let start_line = &self.lines[start.line];
+        let end_line = &self.lines[end.line];
         self.full
-            || self.lines[start.line].left <= start.column
-            || self.lines[end.line].right >= end.column
+            || (start_line.left..=start_line.right).contains(&start.column)
+            || (end_line.left..=end_line.right).contains(&end.column)
             || (start.line + 1..end.line).any(|line| self.lines[line].is_damaged())
     }
 }
diff --git a/alacritty/src/display/mod.rs b/alacritty/src/display/mod.rs
index d0044f8b..d358a7c5 100644
--- a/alacritty/src/display/mod.rs
+++ b/alacritty/src/display/mod.rs
@@ -342,9 +342,13 @@ pub struct Display {
 
     /// Hint highlighted by the mouse.
     pub highlighted_hint: Option<HintMatch>,
+    /// Frames since hint highlight was created.
+    highlighted_hint_age: usize,
 
     /// Hint highlighted by the vi mode cursor.
     pub vi_highlighted_hint: Option<HintMatch>,
+    /// Frames since hint highlight was created.
+    vi_highlighted_hint_age: usize,
 
     pub raw_window_handle: RawWindowHandle,
 
@@ -516,6 +520,8 @@ impl Display {
             font_size,
             window,
             pending_renderer_update: Default::default(),
+            vi_highlighted_hint_age: Default::default(),
+            highlighted_hint_age: Default::default(),
             vi_highlighted_hint: Default::default(),
             highlighted_hint: Default::default(),
             hint_mouse_point: Default::default(),
@@ -759,7 +765,7 @@ impl Display {
         drop(terminal);
 
         // Invalidate highlighted hints if grid has changed.
-        self.validate_hints(display_offset);
+        self.validate_hint_highlights(display_offset);
 
         // Add damage from alacritty's UI elements overlapping terminal.
 
@@ -1017,9 +1023,10 @@ impl Display {
         };
         let mut dirty = vi_highlighted_hint != self.vi_highlighted_hint;
         self.vi_highlighted_hint = vi_highlighted_hint;
+        self.vi_highlighted_hint_age = 0;
 
         // Force full redraw if the vi mode highlight was cleared.
-        if dirty && self.vi_highlighted_hint.is_none() {
+        if dirty {
             self.damage_tracker.frame().mark_fully_damaged();
         }
 
@@ -1055,9 +1062,10 @@ impl Display {
         let mouse_highlight_dirty = self.highlighted_hint != highlighted_hint;
         dirty |= mouse_highlight_dirty;
         self.highlighted_hint = highlighted_hint;
+        self.highlighted_hint_age = 0;
 
-        // Force full redraw if the mouse cursor highlight was cleared.
-        if mouse_highlight_dirty && self.highlighted_hint.is_none() {
+        // Force full redraw if the mouse cursor highlight was changed.
+        if mouse_highlight_dirty {
             self.damage_tracker.frame().mark_fully_damaged();
         }
 
@@ -1331,16 +1339,24 @@ impl Display {
     }
 
     /// Check whether a hint highlight needs to be cleared.
-    fn validate_hints(&mut self, display_offset: usize) {
+    fn validate_hint_highlights(&mut self, display_offset: usize) {
         let frame = self.damage_tracker.frame();
-        for (hint, reset_mouse) in
-            [(&mut self.highlighted_hint, true), (&mut self.vi_highlighted_hint, false)]
-        {
+        let hints = [
+            (&mut self.highlighted_hint, &mut self.highlighted_hint_age, true),
+            (&mut self.vi_highlighted_hint, &mut self.vi_highlighted_hint_age, false),
+        ];
+        for (hint, hint_age, reset_mouse) in hints {
             let (start, end) = match hint {
                 Some(hint) => (*hint.bounds().start(), *hint.bounds().end()),
-                None => return,
+                None => continue,
             };
 
+            // Ignore hints that were created this frame.
+            *hint_age += 1;
+            if *hint_age == 1 {
+                continue;
+            }
+
             // Convert hint bounds to viewport coordinates.
             let start = term::point_to_viewport(display_offset, start).unwrap_or_default();
             let end = term::point_to_viewport(display_offset, end).unwrap_or_else(|| {