bug#71477: 30.0.50; Lock files are not deleted on Windows 98

[Eli Zaretskii <eliz@gnu.org>]

> From: Po Lu <luangruo@yahoo.com>
> Cc: 71477@debbugs.gnu.org
> Date: Tue, 11 Jun 2024 16:15:08 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> From: Po Lu <luangruo@yahoo.com>
> >> Cc: 71477@debbugs.gnu.org
> >> Date: Tue, 11 Jun 2024 15:42:58 +0800
> >> 
> >> Eli Zaretskii <eliz@gnu.org> writes:
> >> 
> >> > Sorry, I don't understand the problems with negative PID values.
> >> > Where exactly in the code of filelock.c it gets in the way?
> >> 
> >> Here:
> >> 
> >>   /* The PID is everything from the last '.' to the ':' or equivalent.  */
> >>   if (! c_isdigit (dot[1])) <--------------
> >>     return EINVAL;
> >>   errno = 0;
> >> 
> >> The first character of the number after the period is `-' on Windows 98.
> >
> > But that is easy to fix without any significant effect on the rest of
> > the code.  For example:
> >
> >   if (! (c_isdigit (dot[1])
> >          || (dot[1] == '-'  && c_isdigit (dot[2]))))
> >     return EINVAL;
> >
> > Are there any problems with the above fix?
> 
> No, but won't leaving the format of the lock file string inconsistent
> with Unix create difficulties elsewhere, as, for example, on a Samba
> share to which Unix systems are also connected?

What inconsistencies, specifically?

The only possible issue I see with allowing a negative PID is that the
code checks for "pid > 0" or "pid < 0" somewhere; if that is the case,
we should replace those with comparisons with -1 instead.

Can you test the above on Windows 9X when you have a chance?  Then we
could install it.

> P.S. is debbugs.gnu.org offline or some such?

It has connectivity problems.  It was already reported.