Re: [[libxml++] [PATCH] clear_internal_subset()]

[Thomas Jarosch <thomas jarosch intra2net com>]

> > I wanted to replace a dtd reference in a parsed document with a new one.
>
> Just
>
> > calling set_internal_subset doesn't work, libxml checks if we already
> > have
>
> at
>
> > dtd and breaks.
> >
> > So I wrote the clear_internal_subset function.
>
> Shouldn't set_internal_subset() do this automatically, without us adding a
> method? It sounds like a and_make_it_work() method - something that belongs
> in implementation instead of API.

This is what Daniel Veillard wrote to me on the libxml mailinglist:
(about freeing the DTD, but I guess the same is true if you try 
to change the DTD)

> All the refernces to the items defined in the DTD like entities
> will become dandling pointers to freed areas. Might work for a
> given application, but a very bad interface to expose in a library API.
> Changing the strings in the DTD sounds safer, but probably don't
> match what you expect. I would only allow this transformation as part
> of a saving mechanism to avoid the broken references problem

I'm still thinking about the best solution right now, creating an empty 
document and use importNode() is only the last option.

As I just want to validate against a given DTD, perhaps I could
implement a validateAgainstExternalDTD() function in libxml++.

Thomas