Public bug reported:
Part of the logic in bin/cleanarch in determining if a From_ line is a valid Unix From_ separator checks if the following line is a valid header. This test is intended to be that the following line contains a colon and only one or more ascii printable characters up to the first colon. It does check for a colon, but only checks that there is at least one ascii printable character at the beginning of the line before the colon.
** Affects: mailman Importance: Low Status: In Progress
** Branch linked: lp:mailman/2.1
** Changed in: mailman Status: In Progress => Fix Committed