bug#20943: 25.0.50; Dired buffers are not always auto-reverted

[Michael Albinus]

Eli Zaretskii <eliz@gnu.org> writes:

> How about instead introducing a buffer-local variable, say
> auto-revert-when-modified, which Dired will set to a non-nil value,
> and auto-revert will test?  Then, when this variable is non-nil,
> auto-revert could disregard the modified status, and revert the
> buffer, if stale, anyway.

I believe we could use the existing <foo>-stale-p mechanism for that
purpose. dired-stale-p shall decide to return a proper value, even if
the dired buffer is modified. It will follow the same logic as you have
proposed above. And we could implement different logic, depending
whether default-directory is a remote file name.

auto-revert-handler shall not cease to work unconditionally, when
buffer-modified-p is non-nil. This check shall be done only for buffers
with a related file (buffer-file-name is non-nil). For all other
buffers, <foo>-stale-p shall decide, whether buffer-modified-p must be
taken into account.

Thinking about, we might even extract a new function
auto-revert-buffer-with-file-stale-p from auto-revert-handler. This
would handle the case for buffers with a non-nil buffer-file-name.
auto-revert-handler would call always the buffer-local <foo>-stale-p
function; the code would be cleaner.

I will try to write such a patch if nobody beats me. Unfortunately, it
will take time; I'm still suffering from my health problems.

Best regards, Michael.