bug#46853: Confusing terminology "face height" instead of "font size"

[Eli Zaretskii <eliz@gnu.org>]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: stefan@marxist.se,  46853@debbugs.gnu.org
> Date: Mon, 01 Mar 2021 21:05:11 +0100
> 
> > Which exactly demonstrates that not all the faces will have their size
> > changed.  Right?
> 
> Sure.  But the rules are a bit more subtle, so I wonder whether talking
> about the "default face" everywhere is the best way of doing it.
> 
> My understanding of what it does is:
> 
> 1) The default face is definitely adjusted (even if it has an explicit
>    :height).
> 
> 2) The header face is also adjusted (even if it has an explicit :height)
>    and you have that variable set.
> 
> 3) All other fonts will also be adjusted, except those with an explicit
>    :height.
> 
> There may be other rules, too (are there other face attributes that
> hinder size changes?), but this seems to indicate to me that we should
> just say (as in Stefan's patches) "changes the size of the fonts", and
> then link to a manual node that explains the three points above?
> 
> Does that sound reasonable? 

Sorry, no, because that would mislead by catering to the "usual" cases
and ignoring the rest.  What I think we should do instead is talk
about the default face, and then add a note that other faces will be
affected if they don't specify :height.  (The special handling of
header-line doesn't have to be mentioned where header-line is not the
most relevant feature; or we could say "see also
`text-scale-remap-header-line' in some of them).