Try to make this test more resistant to dropping from previous runs (ie, files...

Try to make this test more resistant to dropping from previous runs (ie, files that may exist but cause the test to fail).  Should be backported (assuming it works :-)

Lib/test/test_urllib.py

@@ -27,6 +27,7 @@ class urlopen_FileTests(unittest.TestCase):
     def setUp(self):
         """Setup of a temp file to use for testing"""
         self.text = "test_urllib: %s\n" % self.__class__.__name__
+        test_support.unlink(test_support.TESTFN)
         FILE = file(test_support.TESTFN, 'wb')
         try:
             FILE.write(self.text)
@@ -195,6 +196,7 @@ class urlretrieve_FileTests(unittest.TestCase):
     def test_copy(self):
         # Test that setting the filename argument works.
         second_temp = "%s.2" % test_support.TESTFN
+        test_support.unlink(second_temp)
         self.registerFileForCleanUp(second_temp)
         result = urllib.urlretrieve(self.constructLocalFileUrl(
             test_support.TESTFN), second_temp)
@@ -219,6 +221,7 @@ class urlretrieve_FileTests(unittest.TestCase):
             self.assertEqual(count, count_holder[0])
             count_holder[0] = count_holder[0] + 1
         second_temp = "%s.2" % test_support.TESTFN
+        test_support.unlink(second_temp)
         self.registerFileForCleanUp(second_temp)
         urllib.urlretrieve(self.constructLocalFileUrl(test_support.TESTFN),
             second_temp, hooktester)