Finding a branch point in git

Hi,

When discussing git vs. mercurial, and what can mercurial do that git can't, I inevitably see somebody mention that mercurial branches can be used to find the branch point (the point at which a branch started; even if it's a long-lived one that has been merged to 'master' multiple times).

There have been a few solutions in stackoverflow[1], but none that work in all cases.

But I think I've found an ad-hoc one that uses the commit messages to find the first merge of a branch, and then the merge-base.

For reference, if somebody is interested:

---
[alias]
    branch-point = !sh -c 'merge=$(git rev-list --min-parents=2
--grep="Merge.*$1" --all | tail -1) && git merge-base $merge^1
$merge^2'
---

Cheers.

[1] http://stackoverflow.com/questions/1527234/finding-a-branch-point-with-git/