mail locking problems

[utzoo!decvax!ucbvax!unix-wizards]

>From ARPAVAX.wnj at Berkeley Fri Oct  2 11:02:53 1981
There is a bug in the 4.0bsd locking code for the mail program.
The bug is that the different programs use different names for the lock
file: the correct way is to use a file name ending in ``.lock'' in
/usr/spool/mail; I don't remember right now what the broken program
was using.

Diff also the ``v6mail.c'' program, in /usr/src/cmd/berknet/v6mail.c,
I believe the bug fix is there.

This is fixed in 4.1bsd and also by applying the 4.0bsd->4.1bsd
upgrade.