IndexError: list index out of range on SVG 1.1 reference file

Created by: nthykier

scour on the current master branch fails to process several of the SVG 1.1 reference SVGs. Below is one of these failures:

Processing painting-marker-01-f.svg
Traceback (most recent call last):
  File "scour.py", line 3, in <module>
    run()
  File "$GIT_DIR/scour/scour.py", line 3928, in run
    start(options, input, output)
  File "$GIT_DIR/scour/scour.py", line 3896, in start
    out_string = scourString(in_string, options).encode("UTF-8")
  File "$GIT_DIR/scour/scour.py", line 3570, in scourString
    _num_bytes_saved_in_transforms = optimizeTransforms(doc.documentElement, options)
  File "$GIT_DIR/scour/scour.py", line 3020, in optimizeTransforms
    num += optimizeTransforms(child, options)
  File "$GIT_DIR/scour/scour.py", line 3020, in optimizeTransforms
    num += optimizeTransforms(child, options)
  File "$GIT_DIR/scour/scour.py", line 3020, in optimizeTransforms
    num += optimizeTransforms(child, options)
  File "$GIT_DIR/scour/scour.py", line 3007, in optimizeTransforms
    optimizeTransform(transform)
  File "$GIT_DIR/scour/scour.py", line 2969, in optimizeTransform
    if prevArgs[0] == prevArgs[1] == 1:
IndexError: list index out of range

Options used:

scour --enable-id-stripping --enable-comment-stripping --shorten-ids --indent=none  --no-line-breaks --strip-xml-prolog --remove-descriptive-elements --set-precision=8 --set-c-precision=8 --create-groups --remove-titles --remove-descriptions --remove-metadata

Test data is from: https://www.w3.org/Graphics/SVG/Test/20110816/