bug#41200: Displaying a tooltip with x-show-tip gets very slow as more faces are defined

[martin rudalics]

> I was thinking also of the case where no face specs have changed and the
> frame is "normal" (same frame properties as others, basically) so we
> could re-use the faces from another frame.

That's my hope as well.  For years now I'm making frames temporarily
invisible in order to avoid setting up faces for a new frame.

> [ After all, my Emacs sessions typically have dozens of frames, and only
>    one of them (a minibuffer-only frame) has faces setup differently
>    because it's configured to use a slightly larger font.  ]

In my setup the minibuffer-only frame doesn't even do that.

martin