#642 Race condition with summary modification screen

[Daphne Shaw]

I just upgraded to 2.1 and noticed an interesting race
condition with
the summary version of the moderation page.

Take this timeline:

1) user@example.com sends 3 messages to the list
2) moderator visits summary moderation page and sees
the 3 messages
3) user@example.com sends another message to the list
4) moderator clicks "discard" and submits

The end result is that Mailman discards 4 messages,
including the
latest one that the moderator did not get to see.

This does not happen with the old-style "details"
version of the
moderation page.