[dev-context] little unharmful bug in \showfont & using \iffontchar in \definecharacter

[Mojca Miklavec]

> Hi Mojca,
>
> I bet I can guess what goes wrong:
>
> Mojca Miklavec wrote:
> >
> > \mainlanguage[sl] % try "en" or leave this line out and compare
>
> \sl is a language switch now. Those two-letter language switches are
> a bit problematic at times.

Interesting observation. Since I know that \sl stands for something
else, I never bothered about using \sl instead of \language[sl] for
switching the language (except for trying it and figuring out that it
actually didn't work - as expected).

> Sounds like a good idea. Optional perhaps? (because it slows down
> font switching quite a bit).

I didn't know that it would slow down the process that much, but I
could imagine that people who want to use "empty" fonts would
sacrifice those couple of optional seconds to get better results (an
additional \ifuserwanttodothatelse would probably slow down the
process as well :). However, I don't know how to do that anyway, so I
would redefine those commands manually in that case (already happened
a couple of times, although at first I had no idea what to do).

Mojca