Merged revisions 77417 via svnmerge from

Merged revisions 77417 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

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  r77417 | r.david.murray | 2010-01-10 14:18:27 -0500 (Sun, 10 Jan 2010) | 10 lines

  Merged revisions 77412 via svnmerge from
  svn+ssh://pythondev@svn.python.org/python/trunk

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    r77412 | r.david.murray | 2010-01-10 12:41:28 -0500 (Sun, 10 Jan 2010) | 3 lines

    Issue #7119: document that a program-generated Message object
    tree may be mutated when serialized.
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