bug#14629: 24.3.50; (elisp) `Face Attributes', :font -> "font object"

[Eli Zaretskii]

> Date: Mon, 17 Jun 2013 09:37:56 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> 
> >      (*note Attribute Functions::), you may also supply a font spec,
> 
> What is a font spec?  Is it something like the XLFD string above?
> 
> >      a font entity,
> 
> What is a font entity?

There's a cross-reference there to "Low-Level Font", which tells you
something about these objects.

> >      or a string.
> 
> What kind of string?  What's the format?

There's a cross-reference there to "Fonts" in the Emacs manual, which
answers that question.

> >      Emacs converts such values to an appropriate font object,
> 
> As I mentioned before, "font object" seems to be defined nowhere -
> at least not in the node cross-referenced for it.  What is a font
> object?

See above.

> Beyond the doc, there is a real product bug - see #14634.
> In particular, attribute :font seems to have *no effect* when you do,
> for example, this:
> 
> (propertize myfont 'face (list :font myfont))

What is 'myfont' in this example?