bug#38013: [PATCH] Rectangular region selection with mouse

[Eli Zaretskii]

> Date: Fri, 01 Nov 2019 15:17:07 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 38013@debbugs.gnu.org
> 
> > From: Mattias Engdegård <mattiase@acm.org>
> > Date: Fri, 1 Nov 2019 12:53:44 +0100
> > Cc: 38013@debbugs.gnu.org
> > 
> > With the default settings, click and drag (mouse button 1) with meta held 
> > to mark a rectangular region.
> 
> Thanks, I will try.

Tried it.  I see 2 problems:

 . an annoying 1-pixel horizontal movement when I just press
   M-mouse-1, but don't move it; this doesn't happen in a "normal"
   selection by dragging mouse-1
 . problems when dragging the mouse across a TAB -- you cannot select
   just a "part" of the TAB's 8-column white space (see cua-rect.el
   for how this can be done better)

In addition, it looks like making the rectangular selection is very
error-prone: about 40% of the attempts I get a non-rectangular
selection instead, and sometimes the selection "jumps" to the other
side, i.e. I drag the mouse to the right, but get the text from the
mouse to the _left_ selected, and the selection extends to the BOB.

Thanks.