Public bug reported:

When processing the subject_prefix for list mail, Mailman attempts to remove all the redundant Re: bits in the Subject. Under some circumstances this can fail resulting in messages being delivered to the list with subjects like, e.g.,

Subject: [prefix] Re: Re: Re: Re: some message subject

Of course, it was a user's MUA that created a subject with multiple Re: to begin with, but it may not have been so blatant before prefixing manipulations.

** Affects: mailman Importance: Low Assignee: Mark Sapiro (msapiro) Status: New