Potato: Return on empty input inserts blank output line

proc ::potato::send_mushage {window saveonly} {
    variable inputSwap;
    variable conn;
    variable world;

    set c [up]

    if { $window eq "" } {
        set window [connInfo $c input3]
    }


    if { [$window count -chars 1.0 end-1c] == 0 && $conn($c,connected) == 0 } {
        reconnect [up]
        return;
    }

    set w $conn($c,world)

    # Figure out the auto-prefix, if any
    set windowName [textWidgetName [activeTextWidget] $c]
    if { $windowName eq "" } {
        set windows [list _all]
    } else {
        set windows [list $windowName _all]
    }
    if { $w == 0 } {
        set worlds [list 0]
    } else {
        set worlds [list $w 0]
    }
    foreach w $worlds {
        if { [info exists prefix] } {
            break;
        }
        foreach x $windows {
            set pos [lsearch -exact -index 0 $world($w,prefixes) $x]
            if { $pos != -1 } {
                set entry [lindex $world($w,prefixes) $pos]
                if { [lindex $entry 2] == 1 } {
                    set prefix [lindex $entry 1]
                    break;
                }
            }
        }
    }
    if { ![info exists prefix] } {
        set prefix ""
    }

    set txt [$window get 1.0 end-1char]
    $window edit separator
    $window replace 1.0 end ""

    if { $txt eq "" } {
        get_mushageProcess $c ""
        return;
    }

    set inputSwap($window,count) -1
    set inputSwap($window,backup) ""

    addToInputHistory $c $txt

    if { $saveonly } {
        return;
    }

    send_to $c $txt $prefix

    return;

};# ::potato::send_mushage