bug#8789: 23.3; debug backtrace buffer changes window on step-through

[martin rudalics]

>> Emacs 23 reacts in precisely the same manner here.  Emacs 22 doesn't.
>> So this is something that must have changed in between these two
>> versions.  I don't have the slightest idea what may have caused this and
>> whether this qualifies as an error.
>
> It's caused by the calculation of the mode-line.  Try this:
>
>   (setq-default mode-line-remote nil)
>
> and the problem is gone.

Good catch ;-)

So the solution is probably to never enable `debug-on-entry' for
functions that run through the mode-line mechanism.

martin