bug#18195: 24.3.92; window-screen-lines is not accurate

[Dmitry Gutov <dgutov@yandex.ru>]

On 08/06/2014 06:52 AM, Eli Zaretskii wrote:

> Until some user would ask to lift them.

Apparently, every user that tried to change the font understood that any 
resulting problems stemmed from their actions, and so we've never had 
any bug reports about that.

> But if you never want to lift them, why not define colors instead of
> full-fledged faces?  Then those restrictions are really carved in
> stone and clear for all.

Well, there are also text decorations, and users should be able to add 
(most of) them without running into problems.

Faces seem to be a natural fit for themes, and they're supported by 
quite of a few of existing themes out there. Making the 
backward-incompatible change you're suggesting will break that.

Finally, who's to say the current limitations will stay with us forever? 
If Emacs defines a suitable API, the current faces should be able to 
transition seamlessly, while users will also gain the ability to change 
the fonts.