bug#33232: `gnus-summary-line-format' padding doesn’t work in gui when there are multiple-column-width characters

[Eli Zaretskii]

> From: Eric Abrahamsen <eric@ericabrahamsen.net>
> Date: Thu, 01 Nov 2018 16:52:32 -0700
> Cc: 33232@debbugs.gnu.org
> 
> > See Bug#31588, the width of these characters depends on the font, so
> > string-width (which works only on a string) can't give the right answer.
> > Or, from another point of view, it's the font's fault for being too
> > narrow on these characters.
> 
> Yeah, I figured it was probably a font issue, but still it's kind of
> misleading to have a function that *sounds* like it's going to handle
> the font issue, but doesn't.

What part of "string-width" tells you that it handles fonts?