prezto/plugins/git/completions/_git-hub

#compdef git-hub
#autoload

local state remotes remote branches ret=1

_arguments -C -s -S \
  '1::args:->remote' \
  '2::args:->branch' && ret=0

case "$state" in
  (remote)
    remotes=($(
      git config -l \
        | grep 'remote\.[^.]*\.url' \
        | cut -d'.' -f2))
    _describe -t branch 'remotes' remotes && ret=0
  ;;
  (branch)
    remote="$words[(($CURRENT - 1))]"
    branches=($(
      git branch -a \
        | grep "remotes/${remote}" \
        | sed -e 's/[ \*]*//g' -e "s:remotes/${remote}/::g"
    ))
    _describe -t branch 'branches' branches && ret=0
  ;;
esac

return $ret