Fix cut off full width glyphs in last column

This resolves the issue with full width glyphs getting rendered in the
last column. Since they need at least two glyphs, it is not possible to
properly render them in the last column.

Instead of rendering half of the glyph in the last column, with the
other half cut off, an additional spacer is now inserted before the wide
glyph. This means that the specific glyph in question is then three
cells wide.

Fixes #2385.

1 files changed, 16 insertions, 13 deletions

diff --git a/alacritty/src/url.rs b/alacritty/src/url.rs
index e510aa2b..b32a6812 100644
--- a/alacritty/src/url.rs
+++ b/alacritty/src/url.rs
@@ -42,7 +42,7 @@ impl Url {
     }
 
     pub fn end(&self) -> Point {
-        self.lines[self.lines.len() - 1].end.sub(self.num_cols, self.end_offset as usize)
+        self.lines[self.lines.len() - 1].end.sub(self.num_cols, self.end_offset as usize, false)
     }
 }
 
@@ -73,11 +73,6 @@ impl Urls {
 
     // Update tracked URLs
     pub fn update(&mut self, num_cols: usize, cell: RenderableCell) {
-        // Ignore double-width spacers to prevent reset
-        if cell.flags.contains(Flags::WIDE_CHAR_SPACER) {
-            return;
-        }
-
         // Convert cell to character
         let c = match cell.inner {
             RenderableCellContent::Chars(chars) => chars[0],
@@ -85,20 +80,28 @@ impl Urls {
         };
 
         let point: Point = cell.into();
-        let mut end = point;
+        let end = point;
 
         // Reset URL when empty cells have been skipped
-        if point != Point::default() && Some(point.sub(num_cols, 1)) != self.last_point {
+        if point != Point::default() && Some(point.sub(num_cols, 1, false)) != self.last_point {
             self.reset();
         }
 
-        // Extend by one cell for double-width characters
-        if cell.flags.contains(Flags::WIDE_CHAR) {
-            end.col += 1;
-        }
-
         self.last_point = Some(end);
 
+        // Extend current state if a wide char spacer is encountered
+        if cell.flags.contains(Flags::WIDE_CHAR_SPACER) {
+            if let UrlLocation::Url(_, mut end_offset) = self.state {
+                if end_offset != 0 {
+                    end_offset += 1;
+                }
+
+                self.extend_url(point, end, cell.fg, end_offset);
+            }
+
+            return;
+        }
+
         // Advance parser
         let last_state = mem::replace(&mut self.state, self.locator.advance(c));
         match (self.state, last_state) {