[Python-Dev] rfc822_escape doing the right thing?

[stephen emslie]

I've been working on a project that renders PKG-INFO metadata in a
number of ways. I have noticed that fields with any indentation were
flattened out, which is being done in distutils.util.rfc822_escape.
This unfortunately means that you cant use reStructuredText formatting
in your long description (suggested in PEP345), or are limited to a
set that doesn't require indentation (no block quotes, etc.).

It looks like this behavior was intentionally added in  rev 20099, but
that was about 7 years ago - before reStructuredText and eggs. I
wonder if it makes sense to re-think that implementation with this
sort of metadata in mind, assuming this behavior isn't required to be
rfc822 compliant. I think it would certainly be a shame to miss out on
a good thing like proper (renderable) reST in our metadata.

A quick example of what I mean:

>>> rest = """
... a literal python block::
...     >>> import this
... """
>>> print distutils.util.rfc822_escape(rest)

        a literal python block::
        >>> import this

should look something like:

        a literal python block::
            >>> import this


Is distutils being over-cautious in flattening out all whitespace? A
w3c discussion on multiple lines in rfc822 [1] seems to suggest that
whitespace can be 'unfolded' safely, so it seems a shame to be
throwing it away when it can have important meaning.

[1] http://www.w3.org/Protocols/rfc822/3_Lexical.html

Thanks for any comments

Stephen Emslie