Re: [art] New RFCs text formatting

[Julian Reschke <[e-mail]>]

On 29.11.2019 23:18, John C Klensin wrote:
> ...
> I think others have commented on the assumption that pagination
> is good only if the document is headed for a line printer, but
> it may be worth pointing out that a recent errata submission may
> have identified a weakness in rfcdiff.  An erratum submitted
> last April complained about an extended example in RFC 5321
> being internally inconsistent about leading spaces that turn out
> to be important.  (see https://www.rfc-editor.org/errata/eid5711
> for details, but they aren't important).  The problem is that
> the XML source appears to be correct -- leading spaces in both
> parts of the example -- but the XML output (under v2) isn't.

So what caused the problem in the XML output? (my copy of rfc5321.xml
from AUTH48 seems to be truncated, so I can't tell).

> This wasn't caught caught during AUTH48 or earlier, or
> apparently in the decade between 5321's publication and the
> erratum, at least in because the author was relying on rfcdiff
> and it is apparently insensitive to leading, as well as other
> types of spaces.   I don't think that is a case for an emergency

That's a good reminder. I had a similar issue in the past, which I
detected when doing an *actual* diff instead of rfcdiff. It's easy to
forget though.

> fix to rfcdiff, especially one that might have side-effects I
> haven't thought about, nor a fix to v2 of xml2rfc, but it should
> be another reminder than we two be very careful about what
> xml2rfc produces, especially in a world in which the XML is the
> canonical form but that there is no requirement that the IETF's
> favorite xml2rfc processor be used to process that source (and I
> don't know enough to know whether the IETF-approved Style Sheet
> covers this situation or not).

Well, we'd have to know about the actual cause. If it was an HTAB (as
suggested by Carsten), then the answer is:

- rfc2629.xslt added a warning back in 2014

- RFC 7749 warns about HTAB in
<https://greenbytes.de/tech/webdav/rfc7749.html#element.artwork>: "Note
that processors differ in the handling of horizontal TAB characters
(some expand them, some treat them as single spaces), and thus these
ought to be avoided."

- RFC 7791 makes it an error:
<https://greenbytes.de/tech/webdav/rfc7991.html#element.artwork>: "Tab
characters (U+0009) inside of this element are prohibited."

- I'm not sure what xml2rfc does in the current version, but I reported
a bug back in April
(<https://trac.tools.ietf.org/tools/xml2rfc/trac/ticket/403>)

Finally, what do you mean by "IETF-approved Style Sheet"?

Best regards, Julian