bug#17344: 24.3.90; REGRESSION: tooltip semi-transparent in *Completions*

[Drew Adams <drew.adams@oracle.com>]

Some more info about this regression:

(I cannot get a screen capture to show you, because my screen-capture
tool does not capture tooltips.)

If I give another, non-Emacs window-manager window the focus (by clicking
its title bar) then the mouseover tooltip in the *Completions* frame is OK
(normal, not transparent).

And, as I think I said earlier, if I give the minibuffer frame the focus,
same thing: the tooltip is normal, not transparent.  But if I give any other
Emacs frame the focus (including frame *Completions*), e.g., by clicking its
title bar, then the tooltip in *Completions* is transparent.

Note that typically some other frame has the input focus when the minibuffer
is activated, and it keeps the focus during use of the minibuffer.

I'm not real clear on the terminology, however.  Suppose I click the title
bar of a Dired frame or a frame for *Messages*.  Then if I do, say, `M-x',
the minibuffer becomes active and it accepts input.  But it its title bar
is not colored to show that it has the focus - the Dired or whatever frame
that had the focus still has it, as judged by its title bar.

So what kind of focus is this, since typing input puts it in the minibuffer?
The minibuffer frame does not have the "focus", but input goes to it.  (And
a call to `select-frame-set-input-focus' for the minibuffer frame does
change its title bar, "focusing" it, and even after the minibuffer is exited
the minibuffer frame then still has that focus.)