#! /usr/bin/env bash

git symbolic-ref -q HEAD >/dev/null && exit

pwd

declare -a branches
branches=(`git branch --points-at=HEAD | tail -n +2`)
if [ "${#branches[*]}" -eq 0 ]; then
   branches=(`git branch --points-at=HEAD -r | sed 's!^ *origin/!!'`)
fi

if [ "${#branches[*]}" -eq 0 ]; then
   echo "Cannot find a branch" >&2
elif [ "${#branches[*]}" -eq 1 ]; then
   git checkout "${branches[0]}"
else
   echo "Too many branches" >&2
fi