httpd range handling

set ranges [dict get? $reply range]
			if {$ranges ne ""} {
			    Debug.httpd {ranges: $ranges}
			    set ranges [lindex [lassign [split $ranges =] unit] 0]
			    set ranges [split $ranges ,]
			    set ranges [lindex $ranges 0]	;# only handle one range
			    foreach rr $ranges {
				lassign [split $rr -] from to
				lassign [split $to] to
				set size [dict get $reply content-length]
				if {$from eq ""} {
				    set from [expr {$size-$to+1}]
				    set to $size
				} elseif {$to > $size || $to eq ""} {
				    set to [expr {$size-1}]
				}

				lappend range $from $to	;# remember range to send
			    }

			    # send appropriate content range and length fields
			    set code 206	;# partial content
			    dict set reply content-range "bytes $from-$to/$size"
			    dict set reply content-length [expr {$from-$to+1}]