RE: [External] : Re: Strange effect selecting rectangular region

[Drew Adams]

> > They are few master builds I notice this strange effect.
> >
> > Selecting a rectangular region with 'M-C drag mouse-L' produces the
> > rectangular region but when the keys (M, C, mouse-L) are released the
> > related lines appears in yellows as the attached screenshot. This
> > happens often not always and the only way to get that the yellow
> > disappears is to restart Emacs (I have not found a recipe to do that
> > in Emacs).
> 
> The highlighting in your screenshot looks like the secondary selection
> one gets with M-mouse-1.
> 
> I get the behavior you describe when I release the Control key too
> early (i.e. before the mouse button).


FWIW -

This is where it should have been bound by default, IMO:

 (global-set-key [(control x) down-mouse-1]
                 'mouse-drag-region-rectangle)

Together with this:

 (global-set-key [(control x) mouse-1] 'mouse-set-point)


https://lists.gnu.org/archive/html/emacs-devel/2021-11/msg02149.html

https://debbugs.gnu.org/cgi/bugreport.cgi?bug=52130