Whitespace normalization. Ugh, we really need to do this more often.
You might want to review this change as it's my first time. Be gentle. :-)
diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 9117208..6f15d48 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -388,10 +388,10 @@
if not path:
raise ValueError("no path specified")
-
+
start_list = abspath(start).split(sep)
path_list = abspath(path).split(sep)
-
+
# Work out how much of the filepath is shared by start and path.
i = len(commonprefix([start_list, path_list]))