#!/bin/sh

# Check out the first of the given branches that exists,
# looking at both local branches and the ones on `origin`
#
# Usage: git checkout-first-existing-branch <branch> [<branch> ...]

set -eu


if [ $# -eq 0 ]; then
    echo "Usage: git checkout-first-existing-branch <branch> [<branch> ...]" >&2
    exit 2
fi


for _branch in "$@"; do

    if git show-ref --verify --quiet "refs/heads/$_branch" \
    || git show-ref --verify --quiet "refs/remotes/origin/$_branch"; then
        exec git checkout "$_branch"
    fi

done


echo "None of these branches exists: $*" >&2
exit 1