disk_log:accessible_logs also reports pg2:which_groups

[Shawn Pearce]

This is a minor, but strange bug.  In R9C-0, disk_log:accessible_logs/0
reports all pg2 process groups as distributed disk logs.

I found this out by looking at disk_log:accessible_logs, and seeing
all of my pg2 groups in there as well...  This could create a weird
situation if someone actually tried to do post a disk_log event to
one of my process groups.

I realize that no code should do this, as nobody knows what my process
groups are named, so the chances of this happening are exactly 0, but
it does look strange to someone new who is trying to work with disk_log.

Perhaps just a note in the documentation of disk_log indicating this is
a known bug?

It seems to stem from the fact that disk_log assumes all pg2 process
groups are distributed disk_logs, as if nobody else uses pg2...

-- 
Shawn.

  We are Pentium of Borg. Division is futile. You will be approximated.
  (seen in someone's .signature)