[1.6.x] Fixed #21122 -- Improved clean up of test temp directory on Windows

- Fixed test that didn't close the files it opened
- Caught and handled exception when temp directory cannot be removed

Backport of 978e1351a6 of master

tests/files/tests.py

@@ -175,3 +175,6 @@ class FileMoveSafeTests(unittest.TestCase):
 
         # should allow it and continue on if allow_overwrite is True
         self.assertIsNone(file_move_safe(self.file_a, self.file_b, allow_overwrite=True))
+
+        os.close(handle_a)
+        os.close(handle_b)

tests/runtests.py

@@ -162,17 +162,24 @@ def setup(verbosity, test_labels):
 
     return state
 
+
 def teardown(state):
     from django.conf import settings
+
+    try:
         # Removing the temporary TEMP_DIR. Ensure we pass in unicode
         # so that it will successfully remove temp trees containing
         # non-ASCII filenames on Windows. (We're assuming the temp dir
         # name itself does not contain non-ASCII characters.)
         shutil.rmtree(six.text_type(TEMP_DIR))
+    except OSError:
+        print('Failed to remove temp directory: %s' % TEMP_DIR)
+
     # Restore the old settings.
     for key, value in state.items():
         setattr(settings, key, value)
 
+
 def django_tests(verbosity, interactive, failfast, test_labels):
     from django.conf import settings
     state = setup(verbosity, test_labels)
@@ -253,6 +260,7 @@ def bisect_tests(bisection_label, options, test_labels):
         print("***** Source of error: %s" % test_labels[0])
     teardown(state)
 
+
 def paired_tests(paired_test, options, test_labels):
     state = setup(int(options.verbosity), test_labels)
 
@@ -288,6 +296,7 @@ def paired_tests(paired_test, options, test_labels):
     print('***** No problem pair found')
     teardown(state)
 
+
 if __name__ == "__main__":
     from optparse import OptionParser
     usage = "%prog [options] [module module module ...]"