Question

With a view to a bug in git, at the moment git-submodule.sh reads (reordered):

[iterating over command line arguments]
        --reference)
            case "$2" in '') usage ;; esac
            reference="--reference=$2"
            shift
            ;;
        --reference=*)
            reference="$1"
            shift
            ;;
[...]
        if test -n "$reference"
        then
            git-clone $quiet "$reference" -n "$url" "$path" --separate-git-dir "$gitdir"
        else
            git-clone $quiet -n "$url" "$path" --separate-git-dir "$gitdir"
        fi ||
        die "$(eval_gettext "Clone of '\$url' into submodule path '\$path' failed")"

This uses only the last argument given by --reference. I now want to enhance this so that all --reference options are passed on to git-clone. This is trivial for trivial arguments (reference="$reference --reference=$2"), but my mind boggles when thinking about arguments containing white space, quote or shell meta characters.

What is the best practice to escape such accumulated arguments?

Answer 1

Best practice would be to use a bash array:

declare -a references
#...
  --reference)
    case ... esac
    references+=("--reference=$2")
    shift
    ;;
  --reference=*)
    references+=("$1")
    shift
    ;;
#...
# no need to test the array for emptiness
git-clone $quiet "${references[@]}" -n "$url" "$path" --separate-git-dir "$gitdir"

However, the referenced script uses /bin/sh instead.