From: Patrick Drechsler <patrick@pdrechsler.de>
To: emacs-devel@gnu.org
Cc: emacs-pretest-bug@gnu.org
Subject: Re: 23.0.60; [nxml] BOM and utf-8
Date: Thu, 22 May 2008 00:37:11 +0200 [thread overview]
Message-ID: <87mymjs2qw.fsf@pdrechsler.de> (raw)
In-Reply-To: 87r6bvs3jj.fsf@pdrechsler.de
Patrick Drechsler <patrick@pdrechsler.de> writes:
> mah@everybody.org (Mark A. Hershberger) writes:
>
>> Patrick Drechsler <patrick@pdrechsler.de> writes:
>>
>>> is the attached xml file (simple.xml) really invalid (as indicated by
>>> nxhtml) or is this a bug in nxhtml?
>
> s/nxhtml/nxml/
>
>> The file simple.xml is really invalid.
>>
>> http://www.w3.org/TR/2006/REC-xml-20060816/#sec-prolog-dtd
>>
>> The XML spec gives the following syntax description for the prolog of an
>> XML file (I've only copied the relevant parts):
>>
>> [3] S ::= (#x20 | #x9 | #xD | #xA)+
>> [22] prolog ::= XMLDecl? Misc* (doctypedecl Misc*)?
>> [23] XMLDecl ::= '<?xml' VersionInfo EncodingDecl? SDDecl? S? '?>'
>>
>> Note that there is no S before the literal “<?xml" and that "<?xml" is
>> optional.
>>
>> So, yes, an file that contains whitespace before "<?xml" is invalid XML.
>
> Finally having some spare time I read the specs from above and I have a
> followup question concerning your last sentence:
>
> The BOM in my example file is not whitespace, it is xEF xBB xBF (it is
> only displayed as whitespace by Emacs). According to the W3C site this
> is valid:
>
> ,----[ http://www.w3.org/TR/2006/REC-xml-20060816/#charencoding ]
> | Entities encoded in UTF-16 MUST and entities encoded in UTF-8 MAY
> | begin with the Byte Order Mark described by Annex H of [ISO/IEC
> | 10646:2000], section 2.4 of [Unicode], and section 2.7 of [Unicode3]
> | (the ZERO WIDTH NO-BREAK SPACE character, #xFEFF). This is an encoding
> | signature, not part of either the markup or the character data of the
> | XML document. XML processors MUST be able to use this character to
> | differentiate between UTF-8 and UTF-16 encoded documents.
> `----
>
> Also http://www.w3.org/TR/2006/REC-xml-20060816/#sec-guessing-no-ext-info
sorry, wrong link: http://www.w3.org/TR/2006/REC-xml-20060816/#sec-guessing
> and
>
> ,----[ http://www.w3.org/TR/2006/REC-xml-20060816/#sec-guessing-with-ext-info ]
> | If an XML entity is in a file, the Byte-Order Mark and encoding
> | declaration are used (if present) to determine the character encoding.
> `----
>
> sound like a BOM is a legal (although optional) part of a xml file coded
> in utf-8.
>
> But I am not an expert, so please correct my potentially incorrect
> interpretation.
>
> In case my interpretation is correct, this is a bug in emacs' nxml mode.
>
> Cheers,
>
> Patrick
--
._q0p_.
'=(_)='
/ V \
(_/^\_)
next prev parent reply other threads:[~2008-05-21 22:37 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-17 12:31 23.0.60; [nxml] BOM and utf-8 Patrick Drechsler
2008-05-17 14:13 ` Lennart Borgman (gmail)
2008-05-17 16:57 ` Patrick Drechsler
2008-05-17 20:38 ` Mark A. Hershberger
2008-05-21 22:20 ` Patrick Drechsler
2008-05-21 22:37 ` Patrick Drechsler [this message]
2008-05-22 1:33 ` Mark A. Hershberger
2008-05-22 14:43 ` Tom Tromey
2008-05-22 21:24 ` Miles Bader
2008-05-22 4:17 ` tomas
2008-05-22 4:33 ` Miles Bader
2008-05-22 8:28 ` Jason Rumney
2008-05-27 8:22 ` tomas
2008-05-22 17:34 ` Stephen J. Turnbull
2008-05-23 9:05 ` tomas
2008-05-23 21:23 ` Stephen J. Turnbull
2008-05-27 8:20 ` tomas
2008-05-18 2:29 ` Stephen J. Turnbull
2008-05-18 2:30 ` Miles Bader
2008-05-18 3:19 ` Eli Zaretskii
2008-05-18 4:19 ` Stephen J. Turnbull
2008-05-18 8:56 ` Jason Rumney
2008-05-18 11:00 ` Patrick Drechsler
2008-05-19 3:11 ` Stephen J. Turnbull
2008-05-19 14:32 ` Patrick Drechsler
2008-05-19 18:56 ` Eli Zaretskii
2008-05-20 15:16 ` Patrick Drechsler
2008-05-18 15:19 ` joakim
2008-05-18 4:13 ` Stephen J. Turnbull
2008-05-18 5:40 ` Miles Bader
2008-05-18 9:14 ` David Kastrup
2008-05-19 3:05 ` Stephen J. Turnbull
2008-05-18 23:40 ` David Kastrup
2008-05-19 20:34 ` Stephen J. Turnbull
2008-05-19 20:57 ` David Kastrup
2008-05-19 23:36 ` Stephen J. Turnbull
2008-05-20 7:13 ` David Kastrup
2008-05-30 2:47 ` Kenichi Handa
2008-05-30 3:44 ` Miles Bader
2008-05-30 3:59 ` Kenichi Handa
2008-05-19 6:32 ` Lennart Borgman (gmail)
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