Use --internal-diff only for svn >= 1.7.

tests/trychange_unittest.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Unit tests for trychange.py."""
 
 import os
 import sys
 import unittest
@@ skipping 11 matching lines @@
   def setUp(self):
     SuperMoxTestBase.setUp(self)
     self.mox.StubOutWithMock(subprocess2, 'communicate')
     self.mox.StubOutWithMock(trychange, 'RunGit')
     self.mox.StubOutWithMock(trychange.scm.GIT, 'Capture')
     self.mox.StubOutWithMock(trychange.scm.GIT, 'GenerateDiff')
     self.mox.StubOutWithMock(trychange.scm.GIT, 'GetCheckoutRoot')
     self.mox.StubOutWithMock(trychange.scm.GIT, 'GetEmail')
     self.mox.StubOutWithMock(trychange.scm.GIT, 'GetPatchName')
     self.mox.StubOutWithMock(trychange.scm.GIT, 'GetUpstreamBranch')
-    self.mox.StubOutWithMock(trychange.scm.SVN, 'DiffItem')
     self.mox.StubOutWithMock(trychange.scm.SVN, 'GenerateDiff')
     self.mox.StubOutWithMock(trychange.scm.SVN, 'GetCheckoutRoot')
     self.mox.StubOutWithMock(trychange.scm.SVN, 'GetEmail')
     self.fake_root = self.Dir()
     self.expected_files = ['foo.txt', 'bar.txt']
     self.options = trychange.optparse.Values()
     self.options.files = self.expected_files
     self.options.diff = None
     self.options.name = None
     self.options.email = None
@@ skipping 103 matching lines @@
     trychange.scm.GIT.GetEmail(self.fake_root).AndReturn('georges@example.com')
     self.mox.ReplayAll()
     git = trychange.GIT(self.options, self.fake_root, self.options.files)
     self.assertEqual(git.GetFileNames(), self.expected_files)
     self.assertEqual(git.checkout_root, self.fake_root)
     self.assertEqual(git.GenerateDiff(), 'A diff')
 
 
 if __name__ == '__main__':
   unittest.main()