bug#35418: [PATCH] Don't poll auto-revert files that use notification

[Michael Albinus]

Mattias Engdegård <mattiase@acm.org> writes:

Hi Mattias,

>> Thinking about, I'm even not confident that a static value of this
>> indication is sufficient. In dired, it might be set to t when the dired
>> buffer is setup. But what if the dired buffer contains subdirectories?
>> Is it still possible to indicate this by file notifications over
>> default-directory? Don't know, maybe not, and the variable has to be set
>> to nil ...
>
> There is a third possibility: a buffer requires polling, but could
> make use of notification. The distinction is only important when
> `auto-revert-avoid-polling' is set. For example, we could have, say,
> `buffer-auto-revert-by-notification' take the values nil, notify-only
> and notify-and-poll. This permits immediate updates for some changes
> while still not keeping stale information indefinitely.

I haven't seen this requirement yet for any mode. Let's postpone this,
until there is a real request for this kind of distinction.

Furthermore, we shouldn't expect a deep knowledge from major mode
writers about the internals of auto-revert. People might have a hard
time to understand the difference between notify-only and
notify-and-poll.

Best regards, Michael.