Subject: bug#52435: 29.0.50; C-y seems to contain an old contents

From: Michael Heerdegen <[email-masked]>
Date: Tue, 14 Dec 2021 11:59:31 +0100

Peter Dyballa <[email-masked]> writes:

You wrote in an older message:

> The documentation in GNU Emacs 26.1 seems to be clearer:

> 	The mark is "deactivated" by changing the buffer,
> 	and after certain other operations that set the mark but whose
> 	main purpose is something else--for example, incremental search,
> 	M-<, and M->.

> And it states that the region is cleared when changing to another
> buffer.

I'm not sure if "changing the buffer" means "modifying the buffer"
instead of "changing to another buffer".

> I don't think that I have a particular configuration, except
> (transient-mark-mode t). As I wrote on Sunday, a few older versions of
> GNU Emacs show the same behaviour. On a decades old PowerBook I could
> check the behaviour of much older Emacsen and report here.

That would be interesting.

> If you can give me some variable names I can check whether I reset the
> original setting.

What kind of variables do you mean?  IIUC the behavior is not really
depending on options.  It's an implicit thing: commands set the variable
`deactivate-mark', and the command loop checks this variable at the end
of the execution of any command, and when it's non-nil it deactivates
the mark.

> One fact should be stated: using a mouse click to change into another
> buffer clears the mark.

This is done explicitly in `mouse-drag-track'.  Dunno if it's
intentional in this case.

Michael.