Re: [xml] parent pointer

[Daniel Veillard <veillard redhat com>]

On Mon, Apr 30, 2012 at 10:53:31AM -0700, Zhigang Chen wrote:
> Hi all
>
> Occasionally, I have seen some nodes have its parent pointer set to -1. Also they seem to have been freed 
> implicitly, because (1) freeing them explicitly would throw error, (2) not freeing them does not incur 
> memory leaks as reported by xmlMemBlocks.
>
> I am wondering where in the source code the parent pointer is set to -1, and why it's not set to 0.

  The only way this could happen is if you compile with memory debug and
then blocks which were allocated and then freed are overwritten with -1
to catch potential reuse after free errors

  see in xmlMemFree() / xmlmemory.c
  memset(target, -1, p->mh_size);

Daniel

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