Re: [xml] Memory leak / cleanup missing after node creation.

[Igor Zlatkovic <igor zlatkovic com>]

On 24/05/04 16:33, Jose Commins wrote:
>     Thanks.  It is most unfortunate that I have to keep a list of the 
> nodes, since if I free the node using xmlFreeNode before replacing it I 
> lose the node I want to replace - if I free it afterwards I lose the 
> node I replaced it with!

You cannot free a node before you replace it or unlink it from the 
document somehow. It would be like removing a link from a chain and 
expecting the chain to be whole afterwards.

The node you replaced it with should be in the document tree, where the 
old node was.

>     I guess I'll have to keep a list of newNode's that I have assigned, 
> so I can free them later after I have finished with the doc.

I think you have a different problem. In your code, you are replacing an 
element node with a text node. Element nodes can have children, text 
nodes cannot, so the new text node does not adopt the children of the 
old element node. Few lines down the road, you process the children of 
the old element node, means process a fragment which is now outside your 
document tree. The old element node does not have cur_node->next 
anymore, that link now belongs to the new text node.


> static void process_XML_elements(xmlNode *a_node)
> {
> xmlNode *newNode = NULL;
> xmlNode *cur_node = NULL;
> for (cur_node = a_node; cur_node; cur_node = cur_node->next) {
>   switch(cur_node->type)
>   {
>     case XML_ELEMENT_NODE:
>       if(!strcmp("aTest", cur_node->name))
>       {
>          newNode = xmlNewText(theTagReplacements[1]);
>          xmlReplaceNode(cur_node, newNode);
>       }
>       break;
>     default:
>       break;
>   }
>   process_XML_elements(cur_node->children);
> }
> }


Ciao,
Igor