bugfixed 'find lowest subprocess'

It turns out there's a bug, due primarily to testing on zsh and putting the script into bash.

function find_lowest_subprocess() {
    local -i parent=$1
    local pids
    typeset -a pids

    pids=($(pgrep -P $parent))
    while ((${#pids[@]} > 0)); do
        if ((${#pids[@]} > 1)); then
            parent=${pids[0]}
            local i=0
            while ((i < ${#pids[@]})); do
                local sub=$(pgrep -P ${pids[$i]})
                [[ -n $sub ]] && parent=$sub
                ((i=i + 1))
            done
        else
            parent=$pids
        fi
        pids=($(pgrep -P $parent))
    done
    echo $parent
}

Someone, somewhere forgot about the parenthes around the array assignments. Shame on me!