[libvirt] [libvirt-python PATCH 03/23] remove useless check for NULL before Py_XDECREF

[John Ferlan]

On 09/24/2015 10:01 AM, Pavel Hrdina wrote:
> Signed-off-by: Pavel Hrdina <phrdina at redhat.com>
> ---
>  libvirt-override.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/libvirt-override.c b/libvirt-override.c
> index 14aa0e9..114104b 100644
> --- a/libvirt-override.c
> +++ b/libvirt-override.c
> @@ -2303,12 +2303,9 @@ libvirt_virRegisterErrorHandler(ATTRIBUTE_UNUSED PyObject * self,
>            pyobj_f);
>  
>      virSetErrorFunc(NULL, libvirt_virErrorFuncHandler);
> -    if (libvirt_virPythonErrorFuncHandler != NULL) {
> -        Py_XDECREF(libvirt_virPythonErrorFuncHandler);
> -    }
> -    if (libvirt_virPythonErrorFuncCtxt != NULL) {
> -        Py_XDECREF(libvirt_virPythonErrorFuncCtxt);
> -    }
> +
> +    Py_XDECREF(libvirt_virPythonErrorFuncHandler);
> +    Py_XDECREF(libvirt_virPythonErrorFuncCtxt);

I keep looking at this and thinking why?  Why was it added and what is
it protecting.  Looking at libvirt_virErrorFuncHandler it seems only
libvirt_virPythonErrorFuncCtxt gets the Py_XINCREF and that's based on
whether libvirt_virPythonErrorFuncHandler is NULL or not.

Just feels like something subtle is going on. Also it's a register
handler and we're decrementing something that never got incremented.

John
>  
>      if ((pyobj_f == Py_None) && (pyobj_ctx == Py_None)) {
>          libvirt_virPythonErrorFuncHandler = NULL;
>