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

Here's my Emacs devel version:

Emacs version: GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.22.30, cairo version 1.15.12)
 of 2021-07-26, built using commit 1ff02c53b5f21dfcaff1794f3eb2f42fb6160dae.