When attempting to base64-decode a payload of invalid length (1 mod 4),
properly recognize and handle it. The given data will be returned as-is,
i.e. not decoded, along with a new defect, InvalidBase64LengthDefect.
The original algorithm tried to delegate the folding to the tokens so
that those tokens whose folding rules differed could specify the
differences. However, this resulted in a lot of duplicated code because
most of the rules were the same.
The new algorithm moves all folding logic into a set of functions
external to the token classes, but puts the information about which
tokens can be folded in which ways on the tokens...with the exception of
mime-parameters, which are a special case (which was not even
implemented in the old folder).
This algorithm can still probably be improved and hopefully simplified
somewhat.
Note that some of the test expectations are changed. I believe the
changes are toward more desirable and consistent behavior: in general
when (re) folding a line the canonical version of the tokens is
generated, rather than preserving errors or extra whitespace.
Leading whitespace was incorrectly dropped during folding of certain lines in the _header_value_parser's folding algorithm. This makes the whitespace handling code consistent.
It turns out we can't depend on email.message getting imported every place
message_factory is needed, so to avoid a circular import we need to special
case Policy.message_factory=None in the parser instead of using monkey
patching. I had a feeling that was a bad idea when I did it.
This is a wholesale reorganization and editing of the email documentation to
make the new API the standard one, and the old API the 'legacy' one. The
default is still the compat32 policy, for backward compatibility. We will
change that eventually.
This changes the main documentation, doc strings, source code comments, and a
couple error messages in the test suite. In some cases the word was removed
or edited some other way to fix the grammar.
This defaults to True in the compat32 policy for backward compatibility,
but to False for all new policies.
Patch by Milan Oberkirch, with a few tweaks.
This could use more edge case tests, but the basic functionality is tested.
(Note that this changeset does not add tailored support for the RFC 6532
message/global MIME type, but the email package generic facilities will handle
it.)
Reviewed by Maciej Szulik.