[xml] xmlAddChild and xmlUnlinkNode

[Nikolay Sivov <bunglehead gmail com>]

Hi.

It seems to me that xmlAddChild behaviour is kinda unexpected when you 
try to add a node that is altready linked to another document (or node 
of another type). If you don't xmlUnlinkNode before add call this 
results in node being referenced by both documents, so on free is will 
fail (libc crash for me).
It's fine of course to always do xmlUnlinkNode no matter what but what 
bothers me is that xmlAddChild has xmlSetTreeDoc() inside that's called 
if new parent document doesn't match new child's doc. So references are 
fixed for new node only with xmlSetTreeDoc but not for old document it 
seems.
Does it sound reasonable to add xmlUnlinkNode in xmlAddChild or I should 
always unlink manually?
Nikolay

Attachment: test.c
Description: Text document