[virt-tools-list] [osinfo PATCH] Make sure we don't set a GError twice in OSInfoLoader

[Daniel P. Berrange]

On Wed, Nov 30, 2011 at 11:07:24AM +0100, Christophe Fergeau wrote:
> When parsing OSInfo XML documents, the catchXMLError callback may
> be called for non fatal errors. When this happens, we get a pointer
> to a parsed document which we can use, but we may have set a GError
> during the parsing if a non fatal error was logged. This means we
> have to make sure the error is cleared after the parsing, otherwise
> we may attempt to set it twice which is forbidden
> 
> This can be triggered by running examples/demo.py:
> 
> $ python examples/demo.py
> /usr/lib/python2.7/dist-packages/gi/types.py:43: Warning: GError set
> over the top of a previous GError or uninitialized memory.
> This indicates a bug in someone's code. You must ensure an error
> is NULL before it's set.
> The overwriting error message was: Incorrect root element
>   return info.invoke(*args, **kwargs)
> Traceback (most recent call last):
>   File "examples/demo.py", line 6, in <module>
>     loader.process_path("./")
>   File "/usr/lib/python2.7/dist-packages/gi/types.py", line 43, in function
>     return info.invoke(*args, **kwargs)
> gi._glib.GError: at line 18: Namespace prefix xi on include is not defined
> 
> Bug report and initial fix from Guido Günther <agx at sigxcpu.org>
> ---
>  osinfo/osinfo_loader.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/osinfo/osinfo_loader.c b/osinfo/osinfo_loader.c
> index ca634f8..cf176a2 100644
> --- a/osinfo/osinfo_loader.c
> +++ b/osinfo/osinfo_loader.c
> @@ -826,6 +826,12 @@ static void osinfo_loader_process_xml(OsinfoLoader *loader,
>      if (!xml)
>          goto cleanup;
>  
> +    /* catchXMLError may be called for non-fatal errors. If that happens,
> +     * xml will be non-NULL but err may be set. This will cause warnings if
> +     * we try to set err later on, so clear it first.
> +     */
> +    g_clear_error(err);
> +
>      root = xmlDocGetRootElement(xml);
>  
>      if (!root) {

ACK

Daniel
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