bug#22338: 25.0.50; deactivate-mark regression

[Leo Liu]

On 2016-01-16 10:24 +0200, Eli Zaretskii wrote:
> When I try this with different files and different changes actually
> made to the file behind Emacs's back, I see the region deactivate
> every time I revert and the file on disk was really changed.  Maybe it
> doesn't always deactivate the region, but it certainly doesn't always
> keep it active, except when the file on disk didn't change at all.
>
> Do you really see the region remain active every revert, no matter
> what the changes to the file on disk?  Can you show a detailed recipe
> for that?
>
> Anyway, since the documentation never says what will happen with the
> region, I tend to consider this behavior unspecified: why should Lisp
> programs expect anything specific to happen to the region during a
> revert?

How did you revert? C-x C-v or eval (revert-buffer nil t t)? For me the
latter always keeps the region active in 25.0.50 (built on 02 Jan 2016).

>> The trouble is if the file has changed on disk (e.g. by another process
>> such as vim), the mark is still active after the revert.
>
> Why is that trouble?
>
> Thanks.

The trouble is now users have no idea what the active region is. For
example I've experienced reverts that change the active region to cover
nearly the whole buffer. The sane behaviour seems to have the active
region off after revert just like in emacs 24.x.

Leo