RE: Performance problems (CPU 100%) with NULs in files

[Drew Adams]

> What happens is that as I scroll through the file, when
> the NULs are visible, Emacs gets into some intensive
> processing for a long time (minutes, sometimes!).  It
> eventually unwinds and repaints the display, but any
> movement of point sends it into this loop again.  I have
> found that M-< or M-> will quickly reposition away from
> the problem (assuming the beginning and/or end of the file
> do not contain NULs).  Most other movement operations send
> it into the loop.
>
> I understand about encodings, and have messed around with
> forcing it into us-ascii, but it appears not to be related
> to this CPU consumption problem.  Does anyone know how to
> solve this?  I'll file a bug report if this is a legitimate bug.
> I'm just concerned that it's a "feature" of some sort, though
> I hope not.

Are you using the development version of Emacs (aka Emacs 24)?

If so, I have no idea whether this will help or help you find the problem, but
you might try doing this to see if it makes a difference:

(setq-default bidi-display-reordering  nil)

Others might have helpful suggestions.  In any case, especially if you have a
reproducible case starting from `emacs -Q' (no init file), I'd suggest reporting
a bug.  Emacs developers will be able to tell you whether there is really a bug.

Whatever Emacs version you are using, this sounds like a regression wrt the
behavior you report with an older version.