Do not expect arguments after --diff.

1 files changed, 1 insertions, 1 deletions

diff --git a/pep8.py b/pep8.py
index a82a73a..6767d00 100755
--- a/pep8.py
+++ b/pep8.py
@@ -1908,7 +1908,7 @@ def process_options(arglist=None, parse_argv=False):
     if options.testsuite:
         args.append(options.testsuite)
     elif not options.doctest:
-        if parse_argv and not args:
+        if parse_argv and not args and not options.diff:
             if os.path.exists('.pep8'):
                 args = ['.']
             else: