[Mesa-dev] [PATCH 08/21] mesa/samplerobj: Avoid crash in sampler query if texture unit is disabled

[Brian Paul]

On 06/11/2012 12:59 AM, Pauli Nieminen wrote:
> Sampler queries are so far made only for enabled texture unit. But if
> any code would query sampler before checking texture unit state that
> would result to NULL deference.
>
> Making the inline helper easier to use with NULL check makes a lot sense
> because compiler is likely to combine the checks for the current texture.
>
> Signed-off-by: Pauli Nieminen<pauli.nieminen at linux.intel.com>
> ---
>   src/mesa/main/samplerobj.h |    4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/src/mesa/main/samplerobj.h b/src/mesa/main/samplerobj.h
> index 0bfda43..33da894 100644
> --- a/src/mesa/main/samplerobj.h
> +++ b/src/mesa/main/samplerobj.h
> @@ -33,8 +33,10 @@ _mesa_get_samplerobj(struct gl_context *ctx, GLuint unit)
>   {
>      if (ctx->Texture.Unit[unit].Sampler)
>         return ctx->Texture.Unit[unit].Sampler;
> -   else
> +   else if (ctx->Texture.Unit[unit]._Current)
>         return&ctx->Texture.Unit[unit]._Current->Sampler;
> +   else
> +      return NULL;
>   }
>
>

Reviewed-by: Brian Paul <brianp at vmware.com>