content-transfer-encoding=8bit

content-transfer-encoding=8bit

[Vladimir Volovich]

Hi,

i wonder, shouldn't the "content-transfer-encoding=8bit" header be put
into `main' headers of a multipart message, rather then into the
message parts? imho, "content-transfer-encoding=8bit" only has `real'
value when used in the main message headers, and is useless in the
headers of a MIME part.

i.e., gnus should not put "content-transfer-encoding=8bit" into
headers of MIME parts, but should put "content-transfer-encoding=8bit"
into main headers iff a part exists which requires that c-t-t should
be 8bit.

	Best regards, -- Vladimir.

Re: content-transfer-encoding=8bit

[Bjørn Mork]

Vladimir Volovich <vvv@vvv.vsu.ru> writes:

> Hi,
> 
> i wonder, shouldn't the "content-transfer-encoding=8bit" header be put
> into `main' headers of a multipart message, rather then into the
> message parts? imho, "content-transfer-encoding=8bit" only has `real'
> value when used in the main message headers, and is useless in the
> headers of a MIME part.

Nope. Different parts can have different encoding. From RFC2045:

3.  MIME Header Fields

   MIME defines a number of new RFC 822 header fields that are used to
   describe the content of a MIME entity.  These header fields occur in
   at least two contexts:

    (1)   As part of a regular RFC 822 message header.

    (2)   In a MIME body part header within a multipart
          construct.

   The formal definition of these header fields is as follows:

     entity-headers := [ content CRLF ]
                       [ encoding CRLF ]
                       [ id CRLF ]
                       [ description CRLF ]
                       *( MIME-extension-field CRLF )

     MIME-message-headers := entity-headers
                             fields
                             version CRLF
                             ; The ordering of the header
                             ; fields implied by this BNF
                             ; definition should be ignored.

     MIME-part-headers := entity-headers
                          [ fields ]
                          ; Any field not beginning with
                          ; "content-" can have no defined
                          ; meaning and may be ignored.
                          ; The ordering of the header
                          ; fields implied by this BNF
                          ; definition should be ignored.


> i.e., gnus should not put "content-transfer-encoding=8bit" into
> headers of MIME parts, but should put "content-transfer-encoding=8bit"
> into main headers iff a part exists which requires that c-t-t should
> be 8bit.

Only text types can be 8bit "encoded" because of the line length
restriction (998 octets), NUL restriction, and CRLF restriction (must 
be paired).

It's often necessary to mix 8bit and base64 if you have a name like 
mine and want to send binaries :-)


Bjørn
.