bug#18090: 24.4.50; `delete-selection-helper' logic changed for non-mouse region?

[Juri Linkov]

> That change was made due to problems described in this thread:
>
>   http://lists.gnu.org/archive/html/emacs-devel/2007-06/msg01642.html
>
> FWIW, I cannot reproduce the original problem reported by Juri in that
> thread, in Emacs 22.1, which according to my calculations was released
> before the change.  So I cannot dig deeper into the issue, but my
> first thought was that this code needs to be rethought/augmented due
> to changes in Emacs 24 regarding selections, since currently the
> default is not to copy to the kill-ring the region selected by
> dragging the mouse.

I see that mouse operations are not supported by delete-selection-mode
anyway - yanking with <mouse-2> doesn't replace the selected region,
so the whole

             (when (and (string= (buffer-substring-no-properties
                                  (point) (mark))
                                 (car kill-ring))
                        (fboundp 'mouse-region-match)
                        (mouse-region-match))
               (current-kill 1))

could be deleted altogether.  Otherwise, if there is a wish to support
mouse yanking, a separate enhancement request could be created.

> I also don't think I understand your report, Drew.  What exactly is
> the problem you are complaining about?  Surely, the problem is not the
> code, but its effect; however, all you say about the effect is that
> "yanking point is rotated only when the mouse was used".  I don't
> understand what "rotating yanking point" means, let alone why it is
> problematic.

I don't understand this bug report too - in fact, there is no bug,
the purpose of the old change was to remove gratuitous optimization
that breaks keyboard macros (the result of yanking should not depend
on differences between old and new text), and nobody complained
during last 10+ years.

But if Drew wants such optimization, then a new customizable option
could be added.