Mesa (master): vc4: Avoid a null-deref if a sampler index isn't used.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: c8097afe2902c89d6d8a90c1948051680eaca9ae
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=c8097afe2902c89d6d8a90c1948051680eaca9ae

Author: Eric Anholt <eric at anholt.net>
Date:   Mon Aug 18 15:50:48 2014 -0700

vc4: Avoid a null-deref if a sampler index isn't used.

Part of fixing ARB_fragment_program/sparse-samplers

---

 src/gallium/drivers/vc4/vc4_program.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/vc4/vc4_program.c b/src/gallium/drivers/vc4/vc4_program.c
index 20f7a44..fa59847 100644
--- a/src/gallium/drivers/vc4/vc4_program.c
+++ b/src/gallium/drivers/vc4/vc4_program.c
@@ -1270,8 +1270,11 @@ static void
 vc4_setup_shared_key(struct vc4_key *key, struct vc4_texture_stateobj *texstate)
 {
         for (int i = 0; i < texstate->num_textures; i++) {
-                struct pipe_resource *prsc = texstate->textures[i]->texture;
-                key->tex_format[i] = prsc->format;
+                struct pipe_sampler_view *sampler = texstate->textures[i];
+                if (sampler) {
+                        struct pipe_resource *prsc = sampler->texture;
+                        key->tex_format[i] = prsc->format;
+                }
         }
 }