Revert os.py 1.75, and directly implement update.
Fixes #1110478 and #1100235.
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 472d13f..cce6926 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -226,6 +226,13 @@
         os.environ.clear()
         os.environ.update(self.__save)
 
+    # Bug 1110478
+    def test_update(self):
+        if os.path.exists("/bin/sh"):
+            os.environ.update(HELLO="World")
+            value = os.popen("/bin/sh -c 'echo $HELLO'").read().strip()
+            self.assertEquals(value, "World")
+
 class WalkTests(unittest.TestCase):
     """Tests for os.walk()."""