Re: Change in `revert-buffer' behavior [28.0.50]

[Óscar Fuentes]

Kaushal Modi <kaushal.modi@gmail.com> writes:

> Hello,
>
> I use the `revert-buffer' function frequently and after a recent rebuild of
> emacs from master after about a month, I noticed a big difference in its
> behavior.
>
> When I change the read-onlyness of a file from the disk, M-x revert-buffer
> doesn't reflect that change any more. This is really important as I am
> working in a centralized VCS where the files have to be "checked out" i.e.
> make writable before I can modify them.
>
> Now when the commands in the terminal check in and check out the file, the
> read-only/writable status doesn't update when I revert-buffer in Emacs.
>
> *Earlier M-x revert-buffer always showed the correct read-only state. Now,
> I need to kill the buffer and reopen to see the correct status.*
>
> I believe it is kind of related to this commit:
> https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=fcae435f598471a2911641412125c5ac4f73559f

I think that the author was trying to preserve the user's decision about
the read-only-ness of the buffer, assuming that the file's permissions
did not change since last visit.

AFAIK currently we have no method for distinguising if the buffer was
made read-only/writable by the user or because Emacs reflected the file
system's permissions.