Port forward from 2.4 branch:

Patch #1464708 from William McVey: fixed handling of nested comments in mail
addresses.  E.g.

"Foo ((Foo Bar)) <foo@example.com>"

Fixes for both rfc822.py and email package.  This patch needs to be back
ported to Python 2.3 for email 2.5.
diff --git a/Lib/test/test_rfc822.py b/Lib/test/test_rfc822.py
index 0d9f28a..6d22825 100644
--- a/Lib/test/test_rfc822.py
+++ b/Lib/test/test_rfc822.py
@@ -45,6 +45,10 @@
                 print 'extra parsed address:', repr(n), repr(a)
                 continue
             i = i + 1
+            self.assertEqual(mn, n,
+                             "Un-expected name: %s != %s" % (`mn`, `n`))
+            self.assertEqual(ma, a,
+                             "Un-expected address: %s != %s" % (`ma`, `a`))
             if mn == n and ma == a:
                 pass
             else:
@@ -129,6 +133,12 @@
             'To: person@dom.ain (User J. Person)\n\n',
             [('User J. Person', 'person@dom.ain')])
 
+    def test_doublecomment(self):
+        # The RFC allows comments within comments in an email addr
+        self.check(
+            'To: person@dom.ain ((User J. Person)), John Doe <foo@bar.com>\n\n',
+            [('User J. Person', 'person@dom.ain'), ('John Doe', 'foo@bar.com')])
+
     def test_twisted(self):
         # This one is just twisted.  I don't know what the proper
         # result should be, but it shouldn't be to infloop, which is