parseListOfPoints sometimes has empty "nums"

[Sébastien Pierre]

I get the following traceback

```
scour.py -i lib/images/cover-chapter-2.svg -o build/lib/images/cover-chapter-2.svg --remove-metadata --quiet
Traceback (most recent call last):
  File "/home/sebastien/Local/share/scour/scour.py", line 3183, in <module>
    out_string = scourString(in_string, options).encode("UTF-8")
  File "/home/sebastien/Local/share/scour/scour.py", line 2952, in scourString
    cleanPolygon(polygon, options)
  File "/home/sebastien/Local/share/scour/scour.py", line 2164, in cleanPolygon
    pts = parseListOfPoints(elem.getAttribute('points'))
  File "/home/sebastien/Local/share/scour/scour.py", line 2136, in parseListOfPoints
    prev = nums[len(nums)-1]
IndexError: list index out of range
```

and the following fixes it

```
diff scour-fixed.py scour.py
2136,2141c2136,2138
< if len(nums) > 0:
< prev = nums[len(nums)-1]
< if prev[len(prev)-1] in ['e', 'E']:
< nums[len(nums)-1] = prev + '-' + negcoords[j]
< else:
< nums.append( '-'+negcoords[j] )
---
> prev = nums[len(nums)-1]
> if prev[len(prev)-1] in ['e', 'E']:
> nums[len(nums)-1] = prev + '-' + negcoords[j]
```

[Louis Simard (louis-simard-deactivatedaccount)]

cynthia@alakazam ~/scour/scour$ ./scour.py -i ~/temp/cover-chapter-2.svg -o ~/temp/cover-chapter-2.opt.svg --remove-metadata --quiet
cynthia@alakazam ~/scour/scour$ ./scour.py --version
0.26
cynthia@alakazam ~/scour/scour$ ls -la ~/temp/cover*
-rw-rw-r-- 1 cynthia cynthia 26918 Nov 6 13:55 /home/cynthia/temp/cover-chapter-2.opt.svg
-rw-rw-r-- 1 cynthia cynthia 32477 Nov 6 13:53 /home/cynthia/temp/cover-chapter-2.svg

I'm not positive this bug still occurs. What version of Scour are you running, and is it the latest code in the Bazaar repository? (See Code, above in Launchpad, to know how to get the code freom Bazaar.)

[Chris Horn (u-chris-k)]

I'm using 0.26 and see this error, as well.

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

[Alexandru Băluț (a13b)]

I also see this bug with two files, one of them being:
http://upload.wikimedia.org/wikipedia/commons/c/c2/Dublin_Rail_Network3.svg

The "s" parameter received by parseListOfPoints(s) is:
-7.227,-7.227 7.227,-7.227 7.227,7.227 -7.227,7.227

The parseListOfPoints method crashes if the first number is negative. That method needs some cleanup.

[Patrick Storz (ede123)]

Fixed in scour 0.32 [1]

See copy of this bug on GitHub for details
https://github.com/scour-project/scour/issues/87

[1] https://pypi.python.org/pypi/scour