MIME Type Review Request: image/svg+xml

Bjoern Hoehrmann derhoermi at gmx.net
Wed Nov 24 18:28:57 CET 2004


* Chris Lilley wrote:
>BH> Consider a *UTF-8 encoded* document
>BH>
>BH>   Content-Type: application/xml;charset=iso-8859-1
>BH>
>BH>   <?xml version="1.0"?>
>BH>   ...
>BH>   <!--Björn-->
>BH>   ...
>BH>
>BH> With no BOM and using only US-ASCII characters for the rest of the
>BH> document,

>So in this case, although the processor that generated it is non
>conforming, the content is not non conforming (but it should be) and the
>processor that receives it has two possibilities:

I've actually asked to get a better understanding on how you intend to
change RFC3023, yet I am afraid you did not really say what happens with
the document above if RFC3023bis gets approved with your changes. I
would appreciate to know just a, b, c, or what else for the various
cases.

>b) it can note that a required encoding declaration is not present, and
>throw a well formedness error.

It actually can't, 0xC3 0xB6 is a legal sequence in both UTF-8 and
ISO-8859-1, it would need to know that I meant to have "Björn" in the
comment which it cannot know.

>Consider an *8859-1 encoded* document
>
>  Content-Type: application/xml;charset=UTF-8
>
>  <?xml version="1.0"?>
>  ...
>  <!--Björn-->
>  ...
>
>With your proposal, would the well formedness error (bytes occur that
>cannot occur in UTF-8) be silently recovered from if the HTTP
>header overrides it, even for an XML processor, while it would continue
>to fail in other cases (such as server side processing)?

I do not really think I've made a proposal to change RFC3023 other than
that the differences between text/xml and application/xml are removed to
properly reflect running code. I can only tell you what XML 1.0 and RFC
3023 require in these cases but you know that already.

>It would sometimes be b) and sometimes c) depending on the particular
>software and whether its reading from disk on the server or over the
>net. I frankly can't understand how you consider this lack of
>interoperability to be a desirable thing.

I am in fact most interested to learn how you think this can be improved
upon which is why I asked you about the impact of your proposal for the
various cases I've mentioned. What applications currently do does not
really help me to get a better understanding of that.



More information about the Ietf-types mailing list