506,513c506,507
< 		case "$2" in
< 		*\**) # Avoid pulling in multiple branches
< 			die "'$2' contains a wildcard"
< 			;;
< 		*:*) # Don't create a local branch for the subtree
< 			die "'$2' contains a local branch name"
< 			;;
< 		esac
---
> 		git ls-remote --exit-code $1 $2 ||
> 		die "'$2' is not a correct reference on '$1'"
535c529
< 	revs=$(git rev-parse $default --revs-only "$@") || exit $?
---
> 	revs=$(git rev-parse $default --revs-only "$1^{commit}") || exit $?