bug#23478: 25.0.93; Mouse region selection asymmetry

[Eli Zaretskii <eliz@gnu.org>]

> From: Stephen Berman <stephen.berman@gmx.net>
> Cc: npostavs@users.sourceforge.net,  23478@debbugs.gnu.org
> Date: Mon, 04 Jul 2016 00:24:51 +0200
> 
> > I think backward-incompatible behavior should almost always be opt-in,
> > unless we have no choice.
> 
> Opting in does, however, have the problem of discoverability (a NEWS
> entry notwithstanding).

Since this is age-old behavior that no one complained about until now,
we can assume most users won't need it.

> I think opting in is best in cases where it's
> likely that some people may prefer (or some code may depend on) the
> existing behavior, or where the new behavior may bring a disadvantage in
> some case.  But I don't think any of that is likely in this case
> (indeed, I really think the existing behavior is a misfeature).  Your
> concern about the interaction with scroll-conservatively applied to my
> initial patch, but you yourself suggested a better alternative that
> allays this concern.  Given that, I ask again, and not rhetorically, do
> you see a strong downside to having the new behavior be the default?

Let's make one step back and describe the exact change in behavior
with the last patch, OK?  Maybe some of us (e.g., me) don't really
understand what is the change.

Thanks.