bug#15447: (quail-help "korean-hangul") generates errors.

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: crocket <crockabiscuit@gmail.com>, 15447@debbugs.gnu.org
> Date: Tue, 24 Sep 2013 18:18:44 -0400
> 
> >> So, is it not a bug?
> > I don't think it is a bug, although it would be nicer if instead of
> > signaling an error Emacs would say something like "unknown package:
> > FOO".
> 
> I guess it also depends on how we end up calling quail-help.
> After all, the user is not expected to type M-: (quail-help "foobar") RET.

It's a command, but invoking it interactively yields the same
behavior.  You need to have activated an input method that loads some
quail package, before invoking this command, in order to have a help.
korean-hangul doesn't load any quail package, so the command throws an
error.

So I still think a more human-readable error message is in order,
although when invoked interactively the package name is not given, so
some other wording is in order.

It looks like quail-help was designed to be called only by "C-h C-\",
where it behaves reasonably, but since it's a command, it perhaps
should have some minimal harness for when it is invoked by users
directly.