I found a migration script at norwinter.com, which I improved a bit. It will handle wiki pages with full history as well as attachments. It won’t preserve who committed revisions, however – that is hardcoded in the script. So, this is still a hack.
a) copy your MoinMoinWiki data/pages directory to the server that runs your redmine install
b) put the migrate_from_moinmoin.rake script in lib/tasks/ in your Redmine install
c) edit the migrate_from_moinmoin.rake script, replace both instances of YOUR@EMAIL.ADDRESS
d) run rake redmine:migrate_from_moinmoin RAILS_ENV=”production”
e) provide a unique redmine project id and the path to your MoinMoinWiki data/pages directory
And here is my version of migrate_from_moinmoin.rake.
This script worked well enough for me to import MoinMoinWiki version 1.5.7 to Redmine 1.2.0.