[Mesa-dev] [PATCH] intel: fix the wrong code to detect null texture.

[Yuanhan Liu]

On Thu, Sep 22, 2011 at 10:26:37PM -0700, Eric Anholt wrote:
> On Fri, 23 Sep 2011 11:09:14 +0800, Yuanhan Liu <yuanhan.liu at linux.intel.com> wrote:
> > On Thu, Sep 08, 2011 at 09:12:44PM -0700, Kenneth Graunke wrote:
> > > On 09/08/2011 07:56 PM, Yuanhan Liu wrote:
> > > > There is already comments show how to detect a null texture. Fix the
> > > > code to match the comments.
> > > > 
> > > > This would fix the oglc divzero(basic.texQOrWEqualsZero) and
> > > > divzero(basic.texTrivialPrim) test case fail.
> > > > 
> > > > Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
> > > > ---
> > > >  src/mesa/drivers/dri/intel/intel_mipmap_tree.c |    2 +-
> > > >  1 files changed, 1 insertions(+), 1 deletions(-)
> > > > 
> > > > diff --git a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> > > > index f36240d..717e0ae 100644
> > > > --- a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> > > > +++ b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> > > > @@ -137,7 +137,7 @@ intel_miptree_create(struct intel_context *intel,
> > > >     /*
> > > >      * pitch == 0 || height == 0  indicates the null texture
> > > >      */
> > > > -   if (!mt || !mt->total_height) {
> > > > +   if (!mt->total_width || !mt->total_height) {
> > > >        free(mt);
> > > >        return NULL;
> > > >     }
> > > 
> > > I was a bit skeptical about removing the !mt check, but I think it's
> > > actually okay since intel_miptree_create_internal never returns NULL.
> > > 
> > > I had to convince myself of that by writing the patch I'm about to reply
> > > with.  intel_miptree_create_internal has explicit "if (!ok) return NULL"
> > > code in it, but it turns out that ok is statically provable to always be
> > > true.  My patch deletes it.
> > > 
> > > The only other reason it might want to return NULL is if allocation of
> > > the struct intel_mipmap_tree fails, but it doesn't check for that.
> > > Perhaps it should?  (But, it's a tiny struct and I'm pretty sure we fail
> > > to check things like that all over the place, so...eh...)
> > > 
> > > Anyway, this looks right to me.  I'll defer to Eric and Ian though.
> > 
> > Hi Eric and Ian, does this patch looks Ok to you? If no problem
> > reported, I would like to push this patch with a change suggested by
> > Kenneth in this mail to repo next monday.
> 
> Yeah, if you get an R-B and nobody else responds in a few days, you can
> probably just go ahead :)  Anyway, it gets my

Got it. Thanks.
> 
> Reviewed-by: Eric Anholt <eric at anholt.net>
>