Re: svn:mime-type and */*+xml

On 2004-05-17 12:42:25 -0500, Travis P wrote:
> On May 17, 2004, at 11:51 AM, Vincent Lefevre wrote:
>
> >I don't think that PS files can contain binary data (contrary to PDF).
> >Binary is in fact encoded in hexadecimal (0-9,a-f).
>
> I've some evidence that that isn't the case.
>
> http://www.rfc-editor.org/rfc/rfc2046.txt
> Page 17:
> " (7) It is possible to include raw binary information inside
> PostScript in various forms."

OK, but this is not usual. The complete paragraph is:

    (7) It is possible to include raw binary information inside
          PostScript in various forms. This is not recommended
          for use in Internet mail, both because it is not
          supported by all PostScript interpreters and because it
          significantly complicates the use of a MIME Content-
          Transfer-Encoding. (Without such binary, PostScript
          may typically be viewed as line-oriented data. The
          treatment of CRLF sequences becomes extremely
          problematic if binary and line-oriented data are mixed
          in a single Postscript data stream.)

So, in general (and this is the recommended case), it is line-oriented
data.

Note that one can also put binary data in text files.

> >Why not? Probably not with PS-generated files (anyway, marking files
> >as binary doesn't solve conflicts magically),
>
> I never even implied that it did. But if a merge occurs on an
> unmerge-able file, recovering the original modified file could be very
> difficult (maybe even impossible in some cases?).

This could happen with any text file. If you are not sure, do a copy
of your file first.

> You're right about hand-written text PS files. I think that
> hand-written is probably quite the rare exception compared to
> generated files.

They are quite common here.

> Page 4-5:
> 3. Overview Of The Initial Top-Level Media Types
>
> The five discrete top-level media types are:
> .....
> (5) application -- some other kind of data, typically
> either uninterpreted binary data or information to be
> processed by an application. The subtype "octet-
> stream" is to be used in the case of uninterpreted
> binary data, in which case the simplest recommended
> action is to offer to write the information into a file
> for the user. The "PostScript" subtype is also defined
> for the transport of PostScript material. Other
> expected uses for "application" include spreadsheets,
> data for mail-based scheduling systems, and languages
> for "active" (computational) messaging, and word
> processing formats that are not directly readable.
> Note that security considerations may exist for some
> types of application data, most notably
> "application/PostScript" and any form of active
> messaging. These issues are discussed later in this
> document.
>
> I would think that anything application/* (including application/xml)
> should not be treated as mergeable text.

Why not?

Also, mergeable text isn't the real problem for me. I often wish to
see diffs, and this is not possible with files regarded as binary.

I think one needs another svn property to mark files as text or binary.

-- 
Vincent Lefèvre <vincent_at_vinc17.org> - Web: <http://www.vinc17.org/>
100% validated (X)HTML - Acorn / RISC OS / ARM, free software, YP17,
Championnat International des Jeux Mathématiques et Logiques, etc.
Work: CR INRIA - computer arithmetic / SPACES project at LORIA
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