bug#65904: 29.1.50; autorevert can't revert files in a symlink directory

[Michael Albinus]

Eli Zaretskii <eliz@gnu.org> writes:

Hi,

>> 0. emacs -Q
>> 1. use the following code to open an existing file in a symlink directory
>> (progn
>>   (setq auto-revert-use-notify t
>>             auto-revert-interval 3)
>>   (global-auto-revert-mode 1)
>>   (setq find-file-hook (delq 'vc-refresh-state find-file-hook))
>>   (find-file "~/symlink_dir/test.txt"))
>> 
>> 2. modify the test file in external program and save
>> 3. emacs doesn't autorevert the file
>
> AFAICT, we don't support autoreverting symlinks, since Dec 2013, so it
> sounds strange that you say it worked in Emacs 27.
>
> The relevant discussion is here:
>
>   https://lists.gnu.org/archive/html/emacs-devel/2013-12/msg00282.html
>
> The reason for this non-support seems to be performance.
>
> I hope Michael (CC'ed) will be able to tell more about this.

Yes, we don't support autorevert of files in a symlinked directory via
file notifications. There are other bugs with the same topic, see
bug#16113, bug#18883 and bug#64061. I'll merge this bug with the other
ones.

> A workaround is to set auto-revert-use-notify to nil.

Yep.

Best regards, Michael.