svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r87550 | r.david.murray | 2010-12-28 13:54:13 -0500 (Tue, 28 Dec 2010) | 8 lines

  #9824: encode , and ; in cookie values so that browsers don't split on them

  There is a small chance of backward incompatibility here, but only for
  non-SimpleCookie applications reading SimpleCookie generated cookies.  Even
  then, any such ap is likely to be handling escaped values already, and it would
  take a fairly perverse implementation of unescaping to fail to unescape these
  newly escaped chars, so the risk seems minimal.
........