--- a/roundup/anypy/email_.py	Wed Dec 21 11:25:40 2011 +0100
+++ b/roundup/anypy/email_.py	Wed Jan 04 18:55:49 2012 +0100
@@ -1,3 +1,7 @@
+import re
+import binascii
+from email import quoprimime, base64mime
+
 try:
     # Python 2.5+
     from email.parser import FeedParser
@@ -17,3 +21,115 @@
             def close(self):
                 p = Parser()
                 return p.parsestr(''.join(self.content))
+
+# Match encoded-word strings in the form =?charset?q?Hello_World?=
+ecre = re.compile(r'''
+  =\?                   # literal =?
+  (?P<charset>[^?]*?)   # non-greedy up to the next ? is the charset
+  \?                    # literal ?
+  (?P<encoding>[qb])    # either a "q" or a "b", case insensitive
+  \?                    # literal ?
+  (?P<encoded>.*?)      # non-greedy up to the next ?= is the encoded string
+  \?=                   # literal ?=
+  ''', re.VERBOSE | re.IGNORECASE | re.MULTILINE)
+
+
+# Fixed header parser, see my proposed patch and discussions:
+# http://bugs.python.org/issue1079 "decode_header does not follow RFC 2047"
+# http://bugs.python.org/issue1467619 "Header.decode_header eats up spaces"
+# This implements the decode_header specific parts of my proposed patch
+# backported to python2.X
+def decode_header(header):
+    """Decode a message header value without converting charset.
+
+    Returns a list of (string, charset) pairs containing each of the decoded
+    parts of the header.  Charset is None for non-encoded parts of the header,
+    otherwise a lower-case string containing the name of the character set
+    specified in the encoded string.
+
+    header may be a string that may or may not contain RFC2047 encoded words,
+    or it may be a Header object.
+
+    An email.errors.HeaderParseError may be raised when certain decoding error
+    occurs (e.g. a base64 decoding exception).
+    """
+    # If it is a Header object, we can just return the encoded chunks.
+    if hasattr(header, '_chunks'):
+        return [(_charset._encode(string, str(charset)), str(charset))
+                    for string, charset in header._chunks]
+    # If no encoding, just return the header with no charset.
+    if not ecre.search(header):
+        return [(header, None)]
+    # First step is to parse all the encoded parts into triplets of the form
+    # (encoded_string, encoding, charset).  For unencoded strings, the last
+    # two parts will be None.
+    words = []
+    for line in header.splitlines():
+        parts = ecre.split(line)
+        first = True
+        while parts:
+            unencoded = parts.pop(0)
+            if first:
+                unencoded = unencoded.lstrip()
+                first = False
+            if unencoded:
+                words.append((unencoded, None, None))
+            if parts:
+                charset = parts.pop(0).lower()
+                encoding = parts.pop(0).lower()
+                encoded = parts.pop(0)
+                words.append((encoded, encoding, charset))
+    # Now loop over words and remove words that consist of whitespace
+    # between two encoded strings.
+    import sys
+    droplist = []
+    for n, w in enumerate(words):
+        if n>1 and w[1] and words[n-2][1] and words[n-1][0].isspace():
+            droplist.append(n-1)
+    for d in reversed(droplist):
+        del words[d]
+
+    # The next step is to decode each encoded word by applying the reverse
+    # base64 or quopri transformation.  decoded_words is now a list of the
+    # form (decoded_word, charset).
+    decoded_words = []
+    for encoded_string, encoding, charset in words:
+        if encoding is None:
+            # This is an unencoded word.
+            decoded_words.append((encoded_string, charset))
+        elif encoding == 'q':
+            word = quoprimime.header_decode(encoded_string)
+            decoded_words.append((word, charset))
+        elif encoding == 'b':
+            paderr = len(encoded_string) % 4   # Postel's law: add missing padding
+            if paderr:
+                encoded_string += '==='[:4 - paderr]
+            try:
+                word = base64mime.decode(encoded_string)
+            except binascii.Error:
+                raise HeaderParseError('Base64 decoding error')
+            else:
+                decoded_words.append((word, charset))
+        else:
+            raise AssertionError('Unexpected encoding: ' + encoding)
+    # Now convert all words to bytes and collapse consecutive runs of
+    # similarly encoded words.
+    collapsed = []
+    last_word = last_charset = None
+    for word, charset in decoded_words:
+        if isinstance(word, str):
+            pass
+        if last_word is None:
+            last_word = word
+            last_charset = charset
+        elif charset != last_charset:
+            collapsed.append((last_word, last_charset))
+            last_word = word
+            last_charset = charset
+        elif last_charset is None:
+            last_word += BSPACE + word
+        else:
+            last_word += word
+    collapsed.append((last_word, last_charset))
+    return collapsed
+