Well, it's pretty simple[1], really. I used git fetch upstream to grab all the changes from ar. Then I used git reset --hard to reset my master branch to ar's branch, completely destroying everything on my branch, including commits.

Then I used git push -f to force my changes onto GitHub. Voila, now my fork is in the exact same state as ar. Of course, before I did all that, I created the old branch, so I wouldn't lose my work. Here's roughly what I did:

  git branch old
  git push origin old
  ... do stuff ...
  git fetch upstream
  git reset --hard 2be9ac75f67edfe9b3c43a9515dd78acebba6f1c
  git push -f origin

By the way, while I was trying to do that, I found this: http://stackoverflow.com/questions/772846/create-git-branch-...

But their directions are somewhat different from mine. I don't think I needed git pull for instance, and git push origin :master didn't work for me. So I had to use -f to force the push, since git was kindly telling me that it might destroy my commits (which I wanted to do).

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After using git for a while, I gotta say, I like it a lot more than Mercurial. git gives you the power to do stuff, whereas Mercurial seems to hold your hand a lot more, and say, "no I can't let you do that, Dave"

Now, I'm not saying Mercurial is bad, just that I like the raw power of git, in the same way that I like the raw power of Arc. So for me personally, git seems to be the winner.

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