Re: [xml] xmlCopyNode error

[Daniel Veillard <veillard redhat com>]

On Thu, Apr 25, 2002 at 09:56:07AM +0100, martyn 2 russell bt com wrote:
> Ok, I have figured out the dodgy roster problem (genuine mistake on my part
> with buf sizes), however three things:
>
> 1st: If I use xmlUnlinkNode() and xmlFreeNode() I then have to set the node
> (ctxt->myDoc->children) to NULL for the application to continue, else I get
> the same xmlCopyNode error I originally reported.

  that means the unlinked node originally didn't had a proper parent or doc
field.

> 2nd: If I use xmlFreeNodeList() instead of xmlFreeNode(), I need NOT set the
> node to NULL to keep the application from crashing.

  Not sure I can build mentally the full model of what's happening in
your application, not much I analyze from that remark.

> 3rd: The documentation doesn't state whether the node is set to NULL when
> calling xmlFreeNode() or xmlFreeNodeList(), Does it?

  What do you mean by "set to NULL" the content pointed by the xmlNodePtr
passed as an *argument* is freed. Whether its content is modified before being
freed must not change your application behaviour otherwise you're using a stale
pointer. And the references to the freed node from you local variables or 
outside the document cannot be "magically" cleaned up by the routine, it's
your homework.

> In the first case, should I have to set my node to NULL?

  Your question doesn't make much sense. The content of the node, no
for the pointers to that area that may be a good programming habbit.

Daniel

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