[Mesa-dev] [PATCH] draw: fix key comparison with uninitialized value

[sroland at vmware.com]

From: Roland Scheidegger <sroland at vmware.com>

Discovered by accident, valgrind was complaining (could have possibly caused
us to create redundant geometry shader variants).
---
 src/gallium/auxiliary/draw/draw_llvm.c | 3 +++
 src/gallium/auxiliary/draw/draw_llvm.h | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/src/gallium/auxiliary/draw/draw_llvm.c b/src/gallium/auxiliary/draw/draw_llvm.c
index f25dafe..faa6e40 100644
--- a/src/gallium/auxiliary/draw/draw_llvm.c
+++ b/src/gallium/auxiliary/draw/draw_llvm.c
@@ -2315,6 +2315,9 @@ draw_gs_llvm_make_variant_key(struct draw_llvm *llvm, char *store)
 
    key = (struct draw_gs_llvm_variant_key *)store;
 
+   assert(offsetof(struct draw_gs_llvm_variant_key, samplers[0]) == 4);
+   key->pad1 = 0;
+
    key->num_outputs = draw_total_gs_outputs(llvm->draw);
 
    /* All variants of this shader will have the same value for
diff --git a/src/gallium/auxiliary/draw/draw_llvm.h b/src/gallium/auxiliary/draw/draw_llvm.h
index f617a29..67f2170 100644
--- a/src/gallium/auxiliary/draw/draw_llvm.h
+++ b/src/gallium/auxiliary/draw/draw_llvm.h
@@ -332,6 +332,11 @@ struct draw_gs_llvm_variant_key
    unsigned nr_samplers:8;
    unsigned nr_sampler_views:8;
    unsigned num_outputs:8;
+   /*
+    * it is important there are no holes in this struct
+    * (and all padding gets zeroed). 32 bit pad should be enough...
+    */
+   unsigned pad1:8;
 
    struct draw_sampler_static_state samplers[1];
 };
-- 
2.1.4