Fix an unfinished though in my own test code.

(testNewlinesInput and testNewlinesOutput are mine, not Tony's.)

Lib/test/test_io.py

@@ -571,12 +571,12 @@ class TextIOWrapperTest(unittest.TestCase):
             self.assertEquals(txt.read(), "".join(expected))
 
     def testNewlinesOutput(self):
-        import os
-        orig_linesep = os.linesep
         data = "AAA\nBBB\rCCC\n"
         data_lf = b"AAA\nBBB\rCCC\n"
         data_cr = b"AAA\rBBB\rCCC\r"
         data_crlf = b"AAA\r\nBBB\rCCC\r\n"
+        save_linesep = os.linesep
+        try:
             for os.linesep, newline, expected in [
                 ("\n", None, data_lf),
                 ("\r\n", None, data_crlf),
@@ -594,6 +594,8 @@ class TextIOWrapperTest(unittest.TestCase):
                 txt.write(data)
                 txt.close()
                 self.assertEquals(buf.getvalue(), expected)
+        finally:
+            os.linesep = save_linesep
 
     # Systematic tests of the text I/O API