Fix running presubmit_support.py directly

presubmit_support.py

Index: presubmit_support.py
diff --git a/presubmit_support.py b/presubmit_support.py
index 79a61f84a7a0f409eeef28aaa1e795591bc0f2db..f583fb67e263c12a1b345d20b05a85bbab32d9c4 100755
--- a/presubmit_support.py
+++ b/presubmit_support.py
@@ -1183,22 +1183,22 @@ def load_files(options, args):
   """Tries to determine the SCM."""
   change_scm = scm.determine_scm(options.root)
   files = []
+  if args:
+    files = ParseFiles(args, options.recursive)
   if change_scm == 'svn':
     change_class = SvnChange
-    status_fn = scm.SVN.CaptureStatus
+    if not files:
+      files = scm.SVN.CaptureStatus([], options.root)
   elif change_scm == 'git':
     change_class = GitChange
-    status_fn = scm.GIT.CaptureStatus
+    # TODO(maruel): Get upstream.
+    if not files:
+      files = scm.GIT.CaptureStatus([], options.root, None)
   else:
     logging.info('Doesn\'t seem under source control. Got %d files' % len(args))
-    if not args:
+    if not files:
       return None, None
     change_class = Change
-  if args:
-    files = ParseFiles(args, options.recursive)
-  else:
-    # Grab modified files.
-    files = status_fn([options.root])
   return change_class, files