scour fails on some polygons/polylines

This fragment in an svg file will break scour:

<polygon points="-125,-75 -125,125 75,125 75,-75"/>.

Traceback reads:

scour 0.26
Copyright Jeff Schiller, Louis Simard, 2010
Traceback (most recent call last):
  File "scour/scour.py", line 3183, in <module>
    out_string = scourString(in_string, options).encode("UTF-8")
  File "scour/scour.py", line 2952, in scourString
    cleanPolygon(polygon, options)
  File "scour/scour.py", line 2164, in cleanPolygon
    pts = parseListOfPoints(elem.getAttribute('points'))
  File "scour/scour.py", line 2136, in parseListOfPoints
    prev = nums[len(nums)-1]
IndexError: list index out of range

The Reason being, I suppose, that the list of points starts with a negative one.
I worked around with below patch, handle with care:

--- scour/scour-orig.py 2011-07-01 12:19:14.662878583 +0200
+++ scour/scour.py 2011-07-01 12:20:03.402875383 +0200
@@ -2129,6 +2129,9 @@
     if j == 0:
      if negcoords[0] != '':
       nums.append(negcoords[0])
+ # this could be the first point
+ elif len(nums) == 0:
+ nums.append( '-'+negcoords[j] )
     # otherwise all other strings will be negative
     else:
      # unless we accidentally split a number that was in scientific notation