Re: HiDPI support for wave style underlines

[Eli Zaretskii <eliz@gnu.org>]

> From: Stephen Pegoraro <spegoraro@tutive.com>
> Date: Sat, 29 Jul 2017 17:12:20 +0800
> 
> The patch isn't _only_ for hidpi displays but I can see how my
> original wording comes across that way. It provides correct scaled
> underlining for all displays, hidpi or otherwise. I meant to say that
> I have only implemented this for the Xlib side of things, no W32 or
> mac.
> 
> Good point regarding the emacs_abort(), I honestly didn't think through that.
> I have modified x_get_scale_factor to return a new struct
> x_display_scale with x and y components which are used in the wave
> length and height calculation.
> Indentations and comment grammar have been fixed up as well.

Sorry for the long delay.

Thanks, I pushed this with minor changes.  Specifically, the function
you added is only used in the same file where it is defined, so it
should be static and its prototype doesn't need to be in xterm.h.
Also, for returning just 2 values, it is better to provide 2 pointer
arguments than to invent a new struct.