Tagged list-reply doesn't find List-Post: headers

[Smylers]

Using list-reply to reply to multiple mailing list messages in one go doesn't work for auto-detected mailing lists.

Steps to reproduce:

1 Find a couple of messages you have been sent from the same mailing list (one that uses List-Post: headers, such as those run on Mailman).
2 Ensure that you don't have that list's address in a lists or subscribes command.
3 On each message in turn, press L. Mutt will correctly auto-detect the mailing list from the List-Post: header and compose a reply addressed to the list.
4 Now tag each message with t and press ;L to list-reply to all tagged messages. Instead of composing a reply, Mutt gives the error message “No mailing lists found!”.

Clearly if Mutt is capable of detecting the mailing list in each message separately, in can detect it when given both of them together.

Note it is possible to work round the issue by using a subscribe command to explicitly tell Mutt about the list. But that rather defeats the purpose of the auto-detection of Mail-Post: headers, since I might want to tag and list-reply multiple messages on any list.

This is in Mutt 1.5.21, in Ubuntu 11.10 alpha.