bug#16736: Compiling a Lisp file causes display to flash off and on

[Eli Zaretskii <eliz@gnu.org>]

> From: Glenn Morris <rgm@gnu.org>
> Cc: 16736@debbugs.gnu.org, martin rudalics <rudalics@gmx.at>
> Date: Sat, 15 Feb 2014 17:07:38 -0500
> 
> Glenn Morris wrote:
> 
> >>   (while t
> >>     (split-window-below)
> >>     (sit-for 0.05)
> >>     (delete-other-windows)
> >>     (sit-for 0.05))
> >>
> >> Typing "C-x C-e" at the right paren of this in *scratch*, I see no
> >> flickering in the tool bar.  Do you?
> >
> > Oh yes. It looks awful!
> 
> Bisected to:
>     
>     revno: 115971
>     committer: martin rudalics <rudalics@gmx.at>
>     branch nick: trunk
>     timestamp: Sat 2014-01-11 10:31:09 +0100
>     message:
>       Fix handling of internal borders (Bug#16348).

Thanks, but I think we still need more info to find what caused this,
as most of that commit is for non-toolkit builds.

Can you put a breakpoint in change_frame_size_1, on line 5564:

  SET_FRAME_COLS (f, new_cols); <<<<<<<<<<<<<<<<
  FRAME_LINES (f) = new_lines;
  FRAME_TEXT_WIDTH (f) = new_text_width;

and see if that breakpoint breaks when you type "C-x 2" in *scratch*?
If it does break, can you show the values of these:

  new_text_width
  FRAME_TEXT_WIDTH (f)
  new_root_width
  old_root_width
  FRAME_TEXT_TO_PIXEL_WIDTH (f, new_text_width)
  FRAME_INTERNAL_BORDER_WIDTH (f)