Re: autorevert doesn't change mode-line-modified anymore

[Richard Stallman]

    The call to revert-buffer in auto-revert-buffers moved recently to
    auto-revert-handler and was encapsulated with a let statement:
      (let ((buffer-read-only buffer-read-only))
        (revert-buffer 'ignore-auto 'dont-ask 'preserve-modes))

    What was the reason for this change?

The reason was so that if the user had type C-x C-q to change
the value of buffer-read-only, that change should not be lost.

It looks like we can't completely win no matter what we do.
If we bind the variable, we get wrong results if the file's
mode changes.  If we don't bind it, we get wrong results if
the user changes the mode.

I think changes by the user are more common.  So the code
as it is now is better.

I will add a comment about this.