Alacritty calculates the cell width from maximum advance via freetype2. But its value is too wide with some font. So this patch makes it use the average of rasterized glyph width instead of maximum advance.

alacritty-wrong-font-width-workaround.patch

diff --git a/src/display.rs b/src/display.rs
index 14c5a66..a5a8980 100644
--- a/src/display.rs
+++ b/src/display.rs
@@ -239,7 +239,7 @@ impl Display {
         // font metrics should be computed before creating the window in the first
         // place so that a resize is not needed.
         let metrics = glyph_cache.font_metrics();
-        let cell_width = (metrics.average_advance + font.offset().x as f64) as u32;
+        let cell_width = (glyph_cache.true_average_width() + font.offset().x as f64) as u32;
         let cell_height = (metrics.line_height + font.offset().y as f64) as u32;

         Ok((glyph_cache, cell_width as f32, cell_height as f32))
diff --git a/src/renderer/mod.rs b/src/renderer/mod.rs
index 237c841..87cae66 100644
--- a/src/renderer/mod.rs
+++ b/src/renderer/mod.rs
@@ -273,6 +273,10 @@ impl GlyphCache {
             .expect("metrics load since font is loaded at glyph cache creation")
     }

+    pub fn true_average_width(&self) -> f64 {
+        (self.cache.values().fold(0., |sum, g| sum + g.width) / self.cache.len() as f32 + 2.) as f64
+    }
+
     pub fn get<'a, L>(&'a mut self, glyph_key: &GlyphKey, loader: &mut L) -> &'a Glyph
         where L: LoadGlyph
     {