bug#18590: 24.3.93; Scrolling changes/forgets selection

[Drew Adams <drew.adams@oracle.com>]

> But point moves when you scroll, so the selected portion of text
> changes.  The OP wanted the selection to remain unchanged on both
> ends (at least that's my understanding of the report).

Did you see the behavior I suggested might be an improvement?
I think it might respond to what the OP was expecting.

There might be a downside to what I suggested - haven't thought
much about it.  But I do think it responds to the gotcha that
has bitten me and I think is biting the OP.  You have something
selected.  Scrolling gives you the (mistaken) impression that you
are only enlarging that selection.

Consider what mouse-3 does after you have selected some text as
somewhat of an analogy.  It does not matter which end of the
initially selected text point is at.  When you click mouse-3
outside the region, the region is extended to the click position.
Similarly, if you click inside the region, it is reduced to the
click position.  And the other end of the initially selected
region is not changed - regardless of whether point or mark was
at that end.

That is more or less what my suggest was for scrolling: have it
extend (or reduce, if scrolling toward point and away from mark)
the region, but have it keep the other end of the original
region.  It would have to be kept as mark, of course, since
scrolling moves the point end of the region.  That is just what
is done by mouse-3 too: it moves point to the click position
and puts mark at the far end of the region (which position does
not change).