Re: address@hidden: Re: address@hidden: No default for describe-font, but one is advertised]]

[Kevin Rodgers]

Kenichi Handa wrote:
> In article <address@hidden>, Richard Stallman <address@hidden> writes:
>
> > [I sent this message a few weeks ago but did not get a response.]
> > Please help us here.
>
> Sorry for the late response.  Actually, I originally wrote
> describe-font and font-info for debugging fontset facility,
> and forgot about them once they became unnecessary.  :-(
>
> They are not a public API (as far as I know they are not
> documented in info).

I think that's a documentation bug: Some of the describe-* and list-*
user commands defined in mule-diag.el are documented in the Emacs manual
(describe-character-set, describe-coding-system, list-charset-chars,
list-coding-systems, and list-input-methods), so why not the others
(describe-current-coding-system, describe-current-coding-system-briefly,
describe-font, describe-fontset, and list-character-sets)?  They are all
autoloaded, by the way.

> > describe-font gets its default from (cdr (assq 'font (frame-parameters))).
>
> Not exactly.  (assq 'font (frame-parameters)) will return a
> fontset instead of font.  In that case, describe-font
> extract an ASCII font of the fontset, and calls font-info
> with that font.

That's what I tried to summarize in the part that you omitted:

>> and then refined by fontset-info if fontset-query returns non-nil.

> In addtion, font-info returns nil if Emacs has not yet
> opened any font with NAME.

Can you address this question, which was also omitted:

>> But how can font-info return nil for the default font of
>> the selected frame?  Emacs is already displaying text in that font!

FYI, on Windows the problematic font name is

"-outline-Courier New-normal-r-normal-normal-13-97-96-96-c-*-iso8859-1"

(the asterisk is in the average width component)

Thanks,
--
Kevin