bug#23478: 25.0.93; Mouse region selection asymmetry

[Noam Postavsky]

On Thu, Jul 7, 2016 at 12:48 PM, Eli Zaretskii <eliz@gnu.org> wrote:
>> From: Stephen Berman <stephen.berman@gmx.net>
>> Cc: npostavs@users.sourceforge.net,  23478@debbugs.gnu.org
>> Date: Thu, 07 Jul 2016 18:22:42 +0200
>>
>> What do you understand by "selection backward"?
>
> mouse-select-region-backward can be interpreted as "mouse selects
> region backward".
>
>> My intention was to indicate that this variable controls selecting
>> the region when you double-click at region-end
>
> But "region-end" doesn't appear in the name.
>
> How about mouse-select-region-at-region-end ?

IMO, it would be a bit confusing if mouse-select-region-at-region-end
= t implies point gets moved to the beginning. How about
mouse-select-region-move-to-beginning. I also suggest removing mention
of scrolling from docstring, I don't think we need to re-explain how
moving point interacts with scrolling here.

(defcustom mouse-select-region-move-to-beginning nil
  "Effect of selecting a region extending backward from double click.

Nil means keep point at the position clicked (region end);
non-nil means move point to region beginning."
  :version "26.1"
  :type '(choice (const :tag "Don't move point" nil)
                 (const :tag "Move point to beginning of region" t)))