Re: ediff highlighting bug fix

[Simon Liddington]

On Mon, 2 Jul 2001, Kevin Rodgers wrote:
> Simon Liddington wrote:
> > I traced the problem and found that the priority for the overlay was
> > becoming very large and then negative. This was due to two things.
> >
> > 1) ediff-highest-priority was adding together all the overlay priorities
> > for the diff region not just giving a max value.
> ...
> >         * ediff-init.el (ediff-highest-priority): Returns 1 + max of all
> >         overlay priorities not 1 + sum of all overlay priorities.
>
> Nice work.  But can I ask why you effectively do
>
>       (1+ (nth 0 (sort ... '>)))
>
> instead of
>
>       (1+ (apply 'max ...))
>
> That greatly simplifies the patch, since it's just a matter of replacing
> `+' with `max'.
>
> (I say effectively, since you actually used a series of `setq's -- yuck :-)

It's just that I'm not that used to lisp (particularly lists - I 1st
tried to do max on the list itself!!) and actually started off by
doing something quite different and then ended up simplifying it as I
got it to work. As you might expect it converged with the original
code except I didn't spot the final simplification you suggest. Though
my brain must have been processing it in the background because I did
wonder whether max would work with apply yesterday (when I was out
sailing actually!!!).

I tried just changing + for max and checked it still worked which it
did but I spotted that the priority was still increasing. This time it
is due to the fine diffs being calculated before unselecting the old
and selecting the new diff. I also spotted a bug in
ediff-unselect-difference (see Changelog).

So, new patches are attached and here's the extra Changlog entry:

2001-07-03  Simon Liddington  <sjl@zepler.org>

        * ediff-util.el (ediff-next-difference,ediff-previous-difference):
        Turn off fine diffs after calculating so that overlay priority
        does not keep increasing.

        * ediff-util.el (ediff-unselect-difference): Fixed unhighlight of
        fine diffs to unhighlight requested diff (was current diff).



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| Simon Liddington                 | Tel (home): +44 23 8023 7935     |
| sjl@zepler.org                   | Tel (work): +44 23 8068 3521     |
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ediff-init.el.patch
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ediff-util.el.patch
Description: Text document