Mesa (glsl2): glsl2: Avoid null deref in scalar constant unop expressions.

[Eric Anholt]

Module: Mesa
Branch: glsl2
Commit: 570dc0d4004bf09d257b3e4c8664d3c26a8af510
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=570dc0d4004bf09d257b3e4c8664d3c26a8af510

Author: Eric Anholt <eric at anholt.net>
Date:   Wed Jul  7 09:07:09 2010 -0700

glsl2: Avoid null deref in scalar constant unop expressions.

---

 src/glsl/ir_constant_expression.cpp |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp
index 541398a..98cbb6c 100644
--- a/src/glsl/ir_constant_expression.cpp
+++ b/src/glsl/ir_constant_expression.cpp
@@ -151,7 +151,12 @@ ir_constant_visitor::visit(ir_expression *ir)
     */
    unsigned c0_inc = op0_scalar ? 1 : 0;
    unsigned c1_inc = op1_scalar ? 1 : 0;
-   unsigned components = op[op1_scalar ? 0 : 1]->type->components();
+   unsigned components;
+   if (op1_scalar || !op[1]) {
+      components = op[0]->type->components();
+   } else {
+      components = op[1]->type->components();
+   }
 
    switch (ir->operation) {
    case ir_unop_logic_not: