bug#6609: 23.2; Cursor becomes invisible when put over some faces

[Eli Zaretskii <eliz@gnu.org>]

> From: Deniz Dogan <deniz.a.m.dogan@gmail.com>
> Date: Sun, 11 Jul 2010 21:49:12 +0200
> Cc: 6609@debbugs.gnu.org
> 
> Terribly sorry about that. I did mean white foreground on black
> background in the original report!

A world of difference.  I do see this problem on XP as well, then.

Can someone try this on GNU/Linux in a GUI session, please?  I'd like
to know if this problem is specific to w32.

To repeat the recipe:

  emacs -Q

Insert this in the *scratch* buffer:

  (set-background-color "black")
  (set-foreground-color "white")

Evaluate these two lines.  Your cursor will now become invisible.  You
can only see it (a) when it is on some text of a non-default color, or
(b) when the Emacs frame does not have focus, and the cursor is
displayed as a hollow rectangle.

"M-x set-face-background RET cursor RET white RET" fixes the problem.
So my first guess would be that we don't do that automatically as part
of changing the default face, for some reason.