> Steps to reproduce:
>
> 1. Build emacs with --without-x-toolkit
> 2. $ emacs -Q &
> 3. (set-frame-parameter nil 'internal-border-width 10) C-j
>
> Then menubar and toolbar look as if they were cut by the internal
> border (see the attached screenshot).
>
> (We can also see several other garbages in the internal border area,
> but they had been there even on Emacs 24.3.)
>
> This does not happen with Lucid or GTK+ builds.
I can see this here as well. There are many cases when redisplaying a
frame fails in this way, especially after setting a frame parameter.
Bug#14222 is another example. When you maximize the frame and
subsequently restore its previous size the problems usually go away
(that's what I do in such cases).
What we needed here is some simple switch we can set and which causes
the redisplay engine to do a through redisplay instead of trying to be
clever and selectively clear/erase some space formerly occupied by a
scrollbar, fringe or border