Re: [xml] Release of libxml2-2.7.1

[Daniel Veillard <veillard redhat com>]

On Thu, Sep 04, 2008 at 06:16:15PM +0100, Colin Guthrie wrote:
> Rob Richards wrote:
> > Colin Guthrie wrote:
> > > Hi Daniel,
> > >
> > > Daniel Veillard wrote:
> > > >   Python serialization code was broken in 2.7.0 so here is a new release
> > > > with a cleanup of that code, even more isolation of the new buffer type
> > > > from user code and a couple of fixes:
> > > >
> > > > * Portability fix:
> > > >  - Borland C fix (Moritz Both)
> > > > * Bug fixes:
> > > >  - python serialization wrappers
> > > >  - XPath QName corner case handking and leaks (Martin)
> > > > * Improvement:
> > > >  - extend the xmlSave to handle HTML documents and trees
> > > > * Cleanup:
> > > >  - python serialization wrappers
> > > >
> > > >   I hope that one is a good one !
> > >
> > > Not sure if this is the right avenue to report this bug but I'm 
> > > having some fairly serious regressions.
> > >
> > > I've not tested 2.7.0, but 2.7.1 is definitely affected.
> > >
> > > I noticed the problem in PHP parsing of XML, and have submitted a  
> > > bugreport and a test case to the following bug:
> > >
> > > https://qa.mandriva.com/show_bug.cgi?id=43486
> > >
> > > Essentially, when using PHPs older parsing functions (which I thought 
> > > were built on expat rather than libxml2 but it seems not), escaped  
> > > entities in cdata are completely ignored. i.e. > < etc.
> > >
> > > See the attachment on the above bug for a test case which requires 
> > > PHP to be installed.
> > >
> > > Hopefully someone can shed some light on the situation.
> >
> > Can you report this as a PHP bug? It looks like some really old hack  
> > code in the PHP extension in order to mimic some specific expat  
> > functionality. The behavior change you see though resulting from a code 
> > changes in libxml2 is really due to the hackish code in the extension  
> > doing things it wasnt meant to be doing. You're better off using the  
> > xmlreader extension in PHP in any case as its simpler, faster, more  
> > powerful and doesn't have any legacy issues like the old xml extension.
>
> Thanks for the info Rob.
>
> I'll report this to the PHP people.
>
> I'm well aware there are better PHP extensions for XML processing, but  
> sadly I'm maintaining some old code that I don't really want to rip  
> apart unless I have to!

  The only thing I can think of is that libxml2 doesn't anymore ask
though a SAX callback when looking for entities references if they
are in the predefined set. This comes in essence by an old decision
from the XML working group stating that user definition for those 5
entities could not override the default predefined ones. So I guess
that change is logical. Now what is done on top of SAX to result
in that bug, I don't really know :-\

Daniel

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