Re: format=flowed not respected

[Simon Josefsson <jas@extundo.com>]

Steinar Bang <sb@dod.no> writes:

> Messages received sent by Opera M2, has had format=flowed set in the
> headers, but the lines haven't been broken when displayed by Gnus.
>
> Here's an example of such an article:
> 	nntp://news.gmane.org/gmane.test/1013
>
> Is there something I have to set to make format=flowed be used by
> Gnus? 

Um, the lines should be "broken" by the sending client.  The receiving
client should "flow" together "broken" lines if they end with SPC, but
isn't required to do anything else.

So Opera is breaking a SHOULD in RFC 2646 when it does not break the
lines before the 80th column.  Gnus is behaving correctly in this
example, as far as I can tell.

4.1.  Generating Format=Flowed

   When generating Format=Flowed text, lines SHOULD be shorter than 80
   characters.  As suggested values, any paragraph longer than 79
   characters in total length could be wrapped using lines of 72 or
   fewer characters.  While the specific line length used is a matter of
   aesthetics and preference, longer lines are more likely to require
   rewrapping and to encounter difficulties with older mailers.  It has
   been suggested that 66 character lines are the most readable.

   (The reason for the restriction to 79 or fewer characters between
   CRLFs on the wire is to ensure that all lines, even when displayed by
   a non-flowed-aware program, will fit in a standard 80-column screen
   without having to be wrapped.  The limit is 79, not 80, because while
   80 fit on a line, the last column is often reserved for a line-wrap
   indicator.)

   When creating flowed text, the generating agent wraps, that is,
   inserts 'soft' line breaks as needed.  Soft line breaks are added
   between words.  Because a soft line break is a SP CRLF sequence, the
   generating agent creates one by inserting a CRLF after the occurance
   of a space.

   A generating agent SHOULD NOT insert white space into a word (a
   sequence of printable characters not containing spaces).  If faced
   with a word which exceeds 79 characters (but less than 998
   characters, the [SMTP] limit on line length), the agent SHOULD send
   the word as is and exceed the 79-character limit on line length.

   A generating agent SHOULD:

      1.  Ensure all lines (fixed and flowed) are 79 characters or
          fewer in length, counting the trailing space but not
          counting the CRLF, unless a word by itself exceeds 79
          characters.
      2.  Trim spaces before user-inserted hard line breaks.
      3.  Space-stuff lines which start with a space, "From ", or
          ">".
...