Merged revisions 78183-78184 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

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  r78183 | mark.dickinson | 2010-02-14 12:16:43 +0000 (Sun, 14 Feb 2010) | 1 line

  Silence some 'comparison between signed and unsigned' compiler warnings.
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  r78184 | mark.dickinson | 2010-02-14 12:31:26 +0000 (Sun, 14 Feb 2010) | 1 line

  Silence more compiler warnings;  fix an instance of potential undefined behaviour from signed overflow.
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