PDF's as base64 vs. Q/P encoded attachments

[Graham Todd <gtodd@yorku.ca>]

This is just for the information of anyone who has a similar problem
since I'm not too knowledgeable about MIME and encoding schemes.

There was a thread a while ago about how to decide between encoding
schemes for attachments and Lars wrote a function that switched
between them based on efficiency. I think it was decided that if
roughly 1/6 of the characters were non-ASCII, then base64 should be
used otherwise Q/P (I may be wrong here).

So Gnus now tries to encode PDF's I create as Q/P (I'm pretty sure it
didn't do this before).  The problem is that receiving PDF's as Q/P
seems to break the MIME handling of the Windows version of Netscape
Mail somehow so that Windows users that I correspond with couldn't
read the attached PDF files in Acrobat. Acrobat gave an error message
saying the files were broken. As an aside I can detach and read PDF's
sent as Q/P content to myself using the Unix (linux & freebsd)
versions of Acrobat and Netscape just fine.

If the cut-off point for encoding is 1/6 or more non-ASCII characters
most PDF's would/should get encoded as base64 wouldn't they?  Anyway
they appear ASCIIish to Gnus.

I did something like this to fix it:

(push '("application/pdf" base64) mm-content-transfer-encoding-alist)

so that PDF's are always encoded base64.

regards,

-- 
Graham Todd