git stuff I can't remember

gistfile1.sh

# clean up your own junk
git remote prune public

# create a branch based of off a commit
git branch branchname <sha1-of-commit>

# wack a remote branch
git push origin :the_remote_branch

# wack a remote tag
git push origin :refs/tags/tagname

# find the first commit on a branch
git config --global alias.oldest-ancestor '!zsh -c '\''diff -u <(git rev-list --first-parent "${1:-master}") <(git rev-list --first-parent "${2:-HEAD}") | sed -ne "s/^ //p" | head -1'\'' -'