bug#41645: 27.0.91; Combining Grapheme Joiner (#x34f) gui artifacts

[Pip Cet <pipcet@gmail.com>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Pip Cet <pipcet@gmail.com>
>> Cc: dfussner@googlemail.com,  41645@debbugs.gnu.org
>> Date: Thu, 04 Jun 2020 22:48:19 +0000
>> 
>> > The IT_CHARACTER case also does this when the pixel width comes out as
>> > zero:
>> >
>> > 	      it->phys_ascent = it->ascent;
>> > 	      it->phys_descent = it->descent;
>> 
>> > That is, it doesn't trust the ascent/descent values from metrics.
>> > Should we do the same for compositions, or did you see any reasons to
>> > believe the metrics in this case?
>> 
>> The former, I believe. I still think fonts with such glyphs are broken,
>> and we should rely as little as possible on what they say about them.
>> 
>> So I've done that in this new version.
>
> Thanks.  Please push to the master branch, with one nit:
>
>> +  if (glyph_not_available_p)
>> +    {
>> +      s->font_not_found_p = true;
>> +    }
>
> Our style convention is not to use braces when the block entails only
> one line.

Thanks! I'd changed that code and missed that.