Re: Fwd:Suggested code fix for tidy

Charlie <[email protected]> Tue, 26 Jul 2005 10:00:23 -0400
Newsgroups gmane.comp.web.html-tidy.devel
Message-ID <[email protected]> 
Markup like this is no fluke.  It is produced, for example, by most 
server-side-include processors (SSIs).  These typically just slurp the 
entire contents of the specified file and neither strip away header info (a 
job for Tidy --show-body-only) nor validate the character sets match.

If you think about it, there are thousands of possible invalid combinations 
of markup.  XML declarations, document types, headers, header elements, 
body, block structured might occur any place where they do no make 
sense.  As it is, we have a great many of these cases coded up, but we can 
never possibly hope to code them all.  If we did, Tidy would be huge and 
crash under its own weight.  Note, GetToken() is called in a half-dozen 
different places in parser.c.  Also, should we also exclude DOCTYPE 
declarations, XML processing instructions, etc.?

A better approach, imo, that takes advantage of Tidy's design and 
implementation, would be to add an argument to GetToken() to be a bit mask 
of allowable node types.  Any new nodes not expected, can be discarded as 
described.  After the <html> element is found (or inferred), the DocType 
and XMLDecl node types can be removed from the current allowed node 
types.  Once you get past the node type screen in the lexer, the existing 
content model checking (with all its known limitations) will kick in at the 
parser.

My $0.02 worth anyway,
Charlie

At 11:44 PM 7/23/2005 -0700, Terry Teague wrote:
>Forwarded to the list.
>
> >Date: Sat, 23 Jul 2005 16:18:31 -0700
> >From: Bastien Duclaux <[email protected]>
> >Subject: Suggested code fix for tidy
> >Sender: Nobody <[email protected]>
> >To: [email protected]
> >Cc: [email protected]
>
> >
> >Message body follows:
> >
> >Hello Terry,
> >
> >I have found a problem with tidy, and I have a fix for it.
> >
> >Some sites which use XSL transformation to generate content
> >have an incorrect <?xml version="1.0" encoding="...."?> tag
> >inside the body of the HTML document, which makes tidy
> >behave incorrectly.
> >
> >eg:
> ><html>
> >        <head><title>Test Case</title></head>
> >        <body>
> >                <p>Bad!
> >                <?xml version="1.0" encoding="utf-8"?>blablabla
> >        </body>
> ></html>
> >
> >A simply suggested fix is to add the following code block
> >inside ParseHead and ParseBody function at parser.c :
> >
> >(main loop)
> >while ((node = GetToken(doc, mode)) != NULL)
> >    {
> >
> >====> FIX
> >if (node->type == XmlDecl)
> >        {
> >            ReportError(doc, &doc->root, node,
> >DISCARDING_UNEXPECTED);
> >            FreeNode(doc, node);
> >            continue;
> >        }
> >====> END FIX
> >
> >I hope that you will be able to include this in the next
> >version.
> >
> >Best regards,
> >Bastien
>
>
>
>
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