[Mailman-Developers] Scrubber mungs quoted-printable revisited.

[Tokio Kikuchi]

Hi Mark,

Mark Sapiro wrote:

> Recently, I looked in more detail at the actual set_payload() method in
> the email library and I have at least a vague understanding of the
> problem. The problem and my understanding are reported at
> <http://sourceforge.net/tracker/?func=detail&aid=1409455&group_id=5470&atid=105470>.
> I have suggested a patch there which I call a 'Hint at possible fix'.
> This patch could be applied in Scrubber.py.
> 

It's nice that the problem was tracked down. Thank you!

> The patch to Scrubber.py would add to the end of the
> 
> def replace_payload_by_text(msg, text, charset):
> 
> definition making the whole definition
> 
> def replace_payload_by_text(msg, text, charset):
>     # TK: This is a common function in replacing the attachment and the
> main
>     # message by a text (scrubbing).  Also, add a flag indicating it
> has been
>     # scrubbed.
>     del msg['content-type']
>     del msg['content-transfer-encoding']
>     msg.set_payload(text, charset)
>     msg['X-Mailman-Scrubbed'] = 'Yes'
>     if msg.get('content-transfer-encoding') == 'quoted-printable':
>         cset = msg.get_charset()
>         if cset:
>             msg._payload = cset.body_encode(msg._payload)
>             msg._charset = None
> 

I'm rather uneasy with _varname attribute is manupulated everywhere in 
the application code.  Maybe we should override the email.Message 
behaviour by overriding in Mailman.Message.  Also I will add 'base64' in 
encoding check and back out the patches related to the 'X-Mailman-Scruber'.

> 
> The advantage to doing this in Scrubber.py and unconditionally setting
> the decode flag for subsequent get_payload() calls is it makes the
> whole process insensitive to whether or not or when Python email bug #
> 1409455 is fixed. If the bug is fixed, the payload will be encoded and
> msg.get_charset() above will return None so the payload won't be
> encoded a second time. The additional code above can be removed at
> some point after we're sure the email library used by Mailman is fixed.
> 
> 


-- 
Tokio Kikuchi, tkikuchi@ is.kochi-u.ac.jp
http://weather.is.kochi-u.ac.jp/