Make average width computation on ftcr more permissive (Bug#43058)

* src/ftcrfont.c (ftcrfont_open): Use only non-zero width glyphs for
computing average width.

1 files changed, 14 insertions, 10 deletions

diff --git a/src/ftcrfont.c b/src/ftcrfont.c
index a02ff99870e..dc765e5aee4 100644
--- a/src/ftcrfont.c
+++ b/src/ftcrfont.c
@@ -233,6 +233,7 @@ ftcrfont_open (struct frame *f, Lisp_Object entity, int pixel_size)
   cairo_glyph_t stack_glyph;
   font->min_width = font->max_width = 0;
   font->average_width = font->space_width = 0;
+  int n = 0;
   for (char c = 32; c < 127; c++)
     {
       cairo_glyph_t *glyphs = &stack_glyph;
@@ -252,17 +253,20 @@ ftcrfont_open (struct frame *f, Lisp_Object entity, int pixel_size)
           stack_glyph.index = 0;
         }
       int this_width = ftcrfont_glyph_extents (font, stack_glyph.index, NULL);
-      if (this_width > 0
-          && (! font->min_width
-              || font->min_width > this_width))
-        font->min_width = this_width;
-      if (this_width > font->max_width)
-        font->max_width = this_width;
-      if (c == 32)
-        font->space_width = this_width;
-      font->average_width += this_width;
+      if (this_width > 0)
+        {
+          if (! font->min_width || font->min_width > this_width)
+            font->min_width = this_width;
+          if (this_width > font->max_width)
+            font->max_width = this_width;
+          if (c == 32)
+            font->space_width = this_width;
+          font->average_width += this_width;
+          n++;
+        }
     }
-  font->average_width /= 95;
+  if (n)
+    font->average_width /= n;
 
   cairo_scaled_font_extents (ftcrfont_info->cr_scaled_font, &extents);
   font->ascent = lround (extents.ascent);