[PATCH rtems-docs v2] c-user/chains: Correct iteration example code

[Chris Johns]

Looks good.

Thanks
Chris

On 9/3/2023 11:33 am, Kinsey Moore wrote:
> Casting the node returned by rtems_chain_head is incorrect. That node is
> owned by the control structure and use of it post-cast could cause
> memory corruption.
> ---
>  c-user/chains.rst | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/c-user/chains.rst b/c-user/chains.rst
> index f518ef4..2044966 100644
> --- a/c-user/chains.rst
> +++ b/c-user/chains.rst
> @@ -193,10 +193,14 @@ placed on another chain:
>          rtems_chain_initialize_empty (out);
>  
>          node = rtems_chain_head (chain);
> +
> +        /* The node returned by rtems_chain_head() is owned by the chain */
> +        node = rtems_chain_next(node);
> +
>          while (!rtems_chain_is_tail (chain, node))
>          {
>              bar = (foo*) node;
> -            rtems_chain_node* next_node = node->next;
> +            rtems_chain_node* next_node = rtems_chain_next(node);
>              if (strcmp (match, bar->data) == 0)
>              {
>                  rtems_chain_extract (node);