[xml] how to change value of an attribute not attached to element

["Petr Kozelka" <pkozelka centrum cz>]

Hello,

what is the best way to set attribute value when the attribute itself is not
yet attached to any element node ?

I need this to correctly implement DOM wrapper for libxml2 - DOM enables to
create attribute node and handle it independently of its carrying element
just as any other node.

I was experimenting with various functions from tree.h, but without success
(xmlSetProp needs parent element). I know I can do this by copy/pasting some
code from tree.c, which assigns the value to an attribute, but I prefer not
to depend so much on libxml2 internals.

If  it is not currently possible, I suggest to add this possibility to the
xmlNodeSetContent() function, which currently does nothing with attribute
nodes.
(I hope it is a correct place, because xmlNodeGetContent() explicitly
handles XML_ATTRIBUTE_NODE)

Thanks,
Petr