bug#16348: 24.3.50; Increasing internal-border-width cuts menubar and toolbar on non-toolkit builds

[Eli Zaretskii]

> Date: Sun, 05 Jan 2014 11:38:50 +0100
> From: martin rudalics <rudalics@gmx.at>
> Cc: 16348@debbugs.gnu.org
> 
> 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.

I believe what you want is to reset the enabled_p flag of each glyph
row in the current glyph matrix.  But since each window in a GUI
session has its own glyph matrix, you will need to do that for every
window on the current frame.

(Maybe there's a variable that has the same effect, I didn't check.)