Issue #10253: FileIO leaks a file descriptor when trying to open a file

for append that isn't seekable.  Patch by Brian Brazil.

Lib/test/test_fileio.py

@@ -339,6 +339,7 @@ class OtherFileTests(unittest.TestCase):
         f.truncate(15)
         self.assertEqual(f.tell(), 5)
         self.assertEqual(f.seek(0, os.SEEK_END), 15)
+        f.close()
 
     def testTruncateOnWindows(self):
         def bug801631():