Get rid of annoying broken git filter in upgrade

	local original=$(git rev-parse HEAD)

	git reset --hard HEAD

	git fetch origin

	git filter-branch -f --commit-filter '

		if grep -q "Automatically generated"; then

			skip_commit "$@"

		else

			git commit-tree "$@"

		fi' $upstream..HEAD

	test -n "$stash" && git stash apply $stash

	git merge --ff-only $upstream || git reset $original

}