mml-generate-default-type

mml-generate-default-type

[Reiner Steib]

Hi,

`M-x grep RET mml-generate-default-type SPC *.el RET' (in the v5-10
branch) gives:

,----
| grep -nH -e mml-generate-default-type *.el
| mml.el:126:(defvar mml-generate-default-type "text/plain")
| mml.el:440:			  (mml-generate-default-type "text/plain"))
| mml.el:537:	       (mml-generate-default-type (if (equal type "digest")
| mml.el:633:	      (not (equal type mml-generate-default-type))
`----

(1) Is there a good reason for the let-binding in line 440?

		    (let ((mml-boundary (mml-compute-boundary cont))
			  (mml-generate-default-type "text/plain"))
		      (mml-to-mime))

(2) The code...

    (when (or charset
	      parameters
	      flowed
	      (not (equal type mml-generate-default-type))
	      mml-insert-mime-headers-always)
      [...]
      (insert "Content-Type: " type)

    ... suggests that `mml-generate-default-type' is the default
    Content-Type that doesn't need to be declared according to the
    relevant RFC(s).  In this case, `mml-generate-default-type' should
    probably be a constant, I think.  And it should get a doc string.

Bye, Reiner.

[ Cc-ing Katsumi, who pointed me to `mml-generate-default-type' while
  discussing a problem with `mml-attach-file'.  Hopefully the ding
  list will soon be up again. ]
-- 
       ,,,
      (o o)
---ooO-(_)-Ooo---  |  PGP key available  |  http://rsteib.home.pages.de/

Re: mml-generate-default-type

[Katsumi Yamaoka]

>>>>> In <v964uwxufq.fsf@marauder.physik.uni-ulm.de> Reiner Steib wrote:

> `M-x grep RET mml-generate-default-type SPC *.el RET' (in the v5-10
> branch) gives:

> ,----
>| grep -nH -e mml-generate-default-type *.el
>| mml.el:126:(defvar mml-generate-default-type "text/plain")
>| mml.el:440:			  (mml-generate-default-type "text/plain"))
>| mml.el:537:	       (mml-generate-default-type (if (equal type "digest")
>| mml.el:633:	      (not (equal type mml-generate-default-type))
> `----

I looked into it and realized the reason why
`mml-generate-default-type' is needed to be a variable, not a
constant.  It is a variable, but users must not modify the value!

> (1) Is there a good reason for the let-binding in line 440?

> 		    (let ((mml-boundary (mml-compute-boundary cont))
> 			  (mml-generate-default-type "text/plain"))
> 		      (mml-to-mime))

It is because `mml-generate-mime-1' is called recursively when a
user marks two or more articles and forwards them in a single
message.  In that case, `mml-generate-default-type' is bound as
"message/rfc822" for encoding each entire article at the first
time, but it should be "text/plain" to encode each body at the
second time.

The reason it is bound as "message/rfc822" at the first time is
to prevent the `Content-Type: message/rfc822' header being
inserted in each article part.  It is also the reason of the
following.

> (2) The code...

>     (when (or charset
> 	      parameters
> 	      flowed
> 	      (not (equal type mml-generate-default-type))
> 	      mml-insert-mime-headers-always)
>       [...]
>       (insert "Content-Type: " type)

>     ... suggests that `mml-generate-default-type' is the default
>     Content-Type that doesn't need to be declared according to the
>     relevant RFC(s).  In this case, `mml-generate-default-type' should
>     probably be a constant, I think.  And it should get a doc string.

The code is used not only to omit the `Content-Type: text/plain'
header but also to suppress inserting of the
`Content-Type: message/rfc822' header.  In the later case,
`mml-generate-default-type' is bound as "message/rfc822".

Re: mml-generate-default-type

[Reiner Steib]

On Thu, Jul 28 2005, Katsumi Yamaoka wrote:

> I looked into it and realized the reason why
> `mml-generate-default-type' is needed to be a variable, not a
> constant.  It is a variable, but users must not modify the value!

[ more explanations ]

Thanks.

Could you please add (some of) your explanations in the doc string[1]
of `mml-generate-default-type' or as a comment near the defvar?

Bye, Reiner.

[1] Something like "Internal variable ..."
-- 
       ,,,
      (o o)
---ooO-(_)-Ooo---  |  PGP key available  |  http://rsteib.home.pages.de/

Re: mml-generate-default-type

[Katsumi Yamaoka]

>>>>> In <v9hdef843t.fsf@marauder.physik.uni-ulm.de> Reiner Steib wrote:

> Could you please add (some of) your explanations in the doc string[1]
> of `mml-generate-default-type' or as a comment near the defvar?

Okay.  I'll do that together with applying the patch I posted as
<URL:http://article.gmane.org/gmane.emacs.gnus.general/60639>.