Merge email package 4.0 from the sandbox, including documentation, test cases,
and NEWS updates.
diff --git a/Lib/email/encoders.py b/Lib/email/encoders.py
new file mode 100644
index 0000000..06016cd
--- /dev/null
+++ b/Lib/email/encoders.py
@@ -0,0 +1,88 @@
+# Copyright (C) 2001-2006 Python Software Foundation
+# Author: Barry Warsaw
+# Contact: email-sig@python.org
+
+"""Encodings and related functions."""
+
+__all__ = [
+ 'encode_7or8bit',
+ 'encode_base64',
+ 'encode_noop',
+ 'encode_quopri',
+ ]
+
+import base64
+
+from quopri import encodestring as _encodestring
+
+
+
+def _qencode(s):
+ enc = _encodestring(s, quotetabs=True)
+ # Must encode spaces, which quopri.encodestring() doesn't do
+ return enc.replace(' ', '=20')
+
+
+def _bencode(s):
+ # We can't quite use base64.encodestring() since it tacks on a "courtesy
+ # newline". Blech!
+ if not s:
+ return s
+ hasnewline = (s[-1] == '\n')
+ value = base64.encodestring(s)
+ if not hasnewline and value[-1] == '\n':
+ return value[:-1]
+ return value
+
+
+
+def encode_base64(msg):
+ """Encode the message's payload in Base64.
+
+ Also, add an appropriate Content-Transfer-Encoding header.
+ """
+ orig = msg.get_payload()
+ encdata = _bencode(orig)
+ msg.set_payload(encdata)
+ msg['Content-Transfer-Encoding'] = 'base64'
+
+
+
+def encode_quopri(msg):
+ """Encode the message's payload in quoted-printable.
+
+ Also, add an appropriate Content-Transfer-Encoding header.
+ """
+ orig = msg.get_payload()
+ encdata = _qencode(orig)
+ msg.set_payload(encdata)
+ msg['Content-Transfer-Encoding'] = 'quoted-printable'
+
+
+
+def encode_7or8bit(msg):
+ """Set the Content-Transfer-Encoding header to 7bit or 8bit."""
+ orig = msg.get_payload()
+ if orig is None:
+ # There's no payload. For backwards compatibility we use 7bit
+ msg['Content-Transfer-Encoding'] = '7bit'
+ return
+ # We play a trick to make this go fast. If encoding to ASCII succeeds, we
+ # know the data must be 7bit, otherwise treat it as 8bit.
+ try:
+ orig.encode('ascii')
+ except UnicodeError:
+ # iso-2022-* is non-ASCII but still 7-bit
+ charset = msg.get_charset()
+ output_cset = charset and charset.output_charset
+ if output_cset and output_cset.lower().startswith('iso-2202-'):
+ msg['Content-Transfer-Encoding'] = '7bit'
+ else:
+ msg['Content-Transfer-Encoding'] = '8bit'
+ else:
+ msg['Content-Transfer-Encoding'] = '7bit'
+
+
+
+def encode_noop(msg):
+ """Do nothing."""