[issue1974] Use space character as continuation_ws

Lib/email/generator.py

 # Copyright (C) 2001-2006 Python Software Foundation
 # Author: Barry Warsaw
 # Contact: email-sig@python.org
 
 """Classes to generate plain text from a message object tree."""
 
 __all__ = ['Generator', 'DecodedGenerator']
 
 import re
 import sys
@@ skipping 141 matching lines @@
                 # what the encoding is.  There is no safe way to split this
                 # string.  If it's ascii-subset, then we could do a normal
                 # ascii split, but if it's multibyte then we could break the
                 # string.  There's no way to know so the least harm seems to
                 # be to not split the string and risk it being too long.
                 print >> self._fp, v
             else:
                 # Header's got lots of smarts, so use it.
                 print >> self._fp, Header(
                     v, maxlinelen=self._maxheaderlen,
-                    header_name=h, continuation_ws='\t').encode()
+                    header_name=h).encode()
         # A blank line always separates headers from body
         print >> self._fp
 
     #
     # Handlers for writing types and subtypes
     #
 
     def _handle_text(self, msg):
         payload = msg.get_payload()
         if payload is None:
@@ skipping 166 matching lines @@
         return boundary
     b = boundary
     counter = 0
     while True:
         cre = re.compile('^--' + re.escape(b) + '(--)?$', re.MULTILINE)
         if not cre.search(text):
             break
         b = boundary + '.' + str(counter)
         counter += 1
     return b