Mesa (master): ir_to_mesa: Don' t dereference a NULL pointer during copy propagation

[Ian Romanick]

Module: Mesa
Branch: master
Commit: 3803295fc2b9c517e80aa46f2338308e23e64e4a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=3803295fc2b9c517e80aa46f2338308e23e64e4a

Author: Ian Romanick <ian.d.romanick at intel.com>
Date:   Fri Feb 11 15:19:05 2011 -0800

ir_to_mesa: Don't dereference a NULL pointer during copy propagation

The ACP may already be NULL, so don't try to make it NULL again.

This should fix bugzilla #34119.

---

 src/mesa/program/ir_to_mesa.cpp |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp
index d0ec23f..7f905ae 100644
--- a/src/mesa/program/ir_to_mesa.cpp
+++ b/src/mesa/program/ir_to_mesa.cpp
@@ -2754,6 +2754,9 @@ ir_to_mesa_visitor::copy_propagate(void)
 	     */
 	    for (int r = 0; r < this->next_temp; r++) {
 	       for (int c = 0; c < 4; c++) {
+		  if (!acp[4 * r + c])
+		     continue;
+
 		  if (acp[4 * r + c]->src_reg[0].file == PROGRAM_OUTPUT)
 		     acp[4 * r + c] = NULL;
 	       }