bug#34252: 27.0.50; rmail-get-new-mail fails

[john]

Just changing lin 2075 it does not crash but after quite a time it says

Getting mail from /mnt/snout/home/jpff/mbox...
movemail: No locks available for /mnt/snout/home/jpff/mbox
(No new mail has arrived)
0 new messages read
You can run the command ‘rmail-get-new-mail’ with g
0 new messages read

and no mail is read

If I understand the message the problem relates to fie locking somewhee.

I tried earlier o explain this used to work but after a hardware/software 
uorade on the server it failed.

==John ff

On Wed, 30 Jan 2019, Eli Zaretskii wrote:

> > Date: Wed, 30 Jan 2019 18:10:29 +0000 (GMT)
> > From: john <jpff@codemist.co.uk>
> > Cc: 34252@debbugs.gnu.org
> >
> > This could be due to a kernel/NFS problem but te effect on using rmail for
> > my user-base is a real problem.  The problems with proto being nil in
> > rmail-remote-proto-p is clearly wrong and despite your statement it does
> > happen to me on two diffrent computers/users attempting to read mail in
> > emacs via rmail.
>
> If you leave only the one change in the place where Glenn said proto
> could be nil, and revert the changes in the other two places, does the
> problem still happen to you?
>
> Thanks.