Re: Mark

[Bob Proulx <bob@proulx.com>]

ken wrote:
> Hugh Mayfield wrote:
> > Sorry for newbie question.  After a while, Emacs starts behaving all the
> > time as if I have typed C-SPC.  That is, whenever I move point, the text
> > between point and the previous location of point is highlighted.  How do
> > I disable this, please?  Also, how did I invoke it, so I can avoid the
> > same happening again?  Various web searches and looking at the manual
> > left me none the wiser.
> 
> Yeah, that happens to me too.  That "feature" came into emacs a few years
> ago around the same time that some people wanted emacs to act more like
> Windows.  If there's a way to turn it off, I'd like to know too. All I can
> say is, when you see it happening, do "C-g" to turn  off the highlighting.
> It can happen again.  So you do "C-g" again.  Ad infinitum.

The problem as described by Hugh sounds different from what you say.
What Hugh describes sounds like some type of mode breakage.   What you
describe sounds like transient-mark-mode.

  https://www.gnu.org/software/emacs/manual/html_node/emacs/Mark.html

> What's really bad is if you type a printable character when some area
> (region) is highlighted (which you might miss if the region is offscreen or
> if you're not constantly watching the screen).  Then everything highlighted
> will be replaced by that printable character.  Apparently that's what you're
> supposed to want to happen.  Apparently #2, "C-w" is too much work if you
> want to wipe out a block of text.

Not liking that behavior I always disable transient-mark-mode with the
following in my .emacs file.

  (setq transient-mark-mode nil)

Hugh, Please confirm that it does or does not happen when using -Q and
then when using -q.

  emacs -Q

And then if it is okay check with:

  emacs -q

That first disables all initialization.  The second disables user
initialization but allows system initialization.  It is a way of
debugging which emacs init files are causing what behavior to happen.

If it happens with 'emacs' but not 'emacs -q' then it is something in
your personal emacs init files.  If it happens in 'emacs -q' but not
in 'emacs -Q' then it is something in the system init files, probably
due to a packaging error.  If it is in 'emacs -Q' then it is in the
core emacs somewhere and exists as a valid upstream bug.

Bob