master 9ed03040d5: Make average width computation on ftcr more permissive (Bug#43058)

[YAMAMOTO Mitsuharu]

branch: master
commit 9ed03040d5bfb228c8d41f1df44e74a824d0cd44
Author: YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
Commit: YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>

    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.
---
 src/ftcrfont.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/src/ftcrfont.c b/src/ftcrfont.c
index a02ff99870..dc765e5aee 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);