Add future 0.18.2

lib/future/backports/email/encoders.py

@@ -0,0 +1,90 @@
+# Copyright (C) 2001-2006 Python Software Foundation
+# Author: Barry Warsaw
+# Contact: email-sig@python.org
+
+"""Encodings and related functions."""
+from __future__ import unicode_literals
+from __future__ import division
+from __future__ import absolute_import
+from future.builtins import str
+
+__all__ = [
+    'encode_7or8bit',
+    'encode_base64',
+    'encode_noop',
+    'encode_quopri',
+    ]
+
+
+try:
+    from base64 import encodebytes as _bencode
+except ImportError:
+    # Py2 compatibility. TODO: test this!
+    from base64 import encodestring as _bencode
+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 encode_base64(msg):
+    """Encode the message's payload in Base64.
+
+    Also, add an appropriate Content-Transfer-Encoding header.
+    """
+    orig = msg.get_payload()
+    encdata = str(_bencode(orig), 'ascii')
+    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/decode to ASCII
+    # succeeds, we know the data must be 7bit, otherwise treat it as 8bit.
+    try:
+        if isinstance(orig, str):
+            orig.encode('ascii')
+        else:
+            orig.decode('ascii')
+    except UnicodeError:
+        charset = msg.get_charset()
+        output_cset = charset and charset.output_charset
+        # iso-2022-* is non-ASCII but encodes to a 7-bit representation
+        if output_cset and output_cset.lower().startswith('iso-2022-'):
+            msg['Content-Transfer-Encoding'] = '7bit'
+        else:
+            msg['Content-Transfer-Encoding'] = '8bit'
+    else:
+        msg['Content-Transfer-Encoding'] = '7bit'
+    if not isinstance(orig, str):
+        msg.set_payload(orig.decode('ascii', 'surrogateescape'))
+
+
+def encode_noop(msg):
+    """Do nothing."""
+    # Well, not quite *nothing*: in Python3 we have to turn bytes into a string
+    # in our internal surrogateescaped form in order to keep the model
+    # consistent.
+    orig = msg.get_payload()
+    if not isinstance(orig, str):
+        msg.set_payload(orig.decode('ascii', 'surrogateescape'))