#!/bin/bash
set -e
set -x

if ! git diff-index --quiet HEAD; then
    set +x
    echo "There are uncommitted changes:"
    git status --short
    echo "Doing nothing to avoid losing your work."
    exit 1
fi
request_id="$1"
remote=${2:-"upstream"}
git fetch "$remote" "pull/$request_id/head"
git reset --hard FETCH_HEAD