Merged revisions 77517,77525 via svnmerge from

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

........
  r77517 | r.david.murray | 2010-01-16 00:15:17 -0500 (Sat, 16 Jan 2010) | 6 lines

  Issue #1670765: Prevent email.generator.Generator from re-wrapping
  headers in multipart/signed MIME parts, which fixes one of the sources of
  invalid modifications to such parts by Generator.  Patch and tests by
  Martin von Gagern.
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  r77525 | r.david.murray | 2010-01-16 11:08:32 -0500 (Sat, 16 Jan 2010) | 2 lines

  Fix issue number in comment.
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1 files changed, 11 insertions, 0 deletions

diff --git a/Lib/email/generator.py b/Lib/email/generator.py
index ed832a3e9a..ba3ccd8988 100644
--- a/Lib/email/generator.py
+++ b/Lib/email/generator.py
@@ -235,6 +235,17 @@ class Generator:
             print >> self._fp
             self._fp.write(msg.epilogue)
 
+    def _handle_multipart_signed(self, msg):
+        # The contents of signed parts has to stay unmodified in order to keep
+        # the signature intact per RFC1847 2.1, so we disable header wrapping.
+        # RDM: This isn't enough to completely preserve the part, but it helps.
+        old_maxheaderlen = self._maxheaderlen
+        try:
+            self._maxheaderlen = 0
+            self._handle_multipart(msg)
+        finally:
+            self._maxheaderlen = old_maxheaderlen
+
     def _handle_message_delivery_status(self, msg):
         # We can't just write the headers directly to self's file object
         # because this will leave an extra newline between the last header