I've successfully connected github to redmine and whenever someone puts an issue reference in a commit message and pushes it to github, a comment is added to the redmine issue referring back to the git commit. This is all fine and well, except that I end up with duplicates. I'm not sure what causes the duplicate, but I think it's when the commit is part of a non-fast-forward merge.
What can I do to prevent the duplicates? I had a look at the github hook to understand how it was getting a list of git commits, but couldn't follow it.