fix tempReg test in _mesa_combine_programs()
diff --git a/src/mesa/shader/program.c b/src/mesa/shader/program.c
index e06ab5a..a0817a9 100644
--- a/src/mesa/shader/program.c
+++ b/src/mesa/shader/program.c
@@ -602,7 +602,7 @@
if ((progA->OutputsWritten & (1 << FRAG_RESULT_COLR)) &&
(progB->InputsRead & (1 << FRAG_ATTRIB_COL0))) {
GLint tempReg = _mesa_find_free_register(newProg, PROGRAM_TEMPORARY);
- if (!tempReg) {
+ if (tempReg < 0) {
_mesa_problem(ctx, "No free temp regs found in "
"_mesa_combine_programs(), using 31");
tempReg = 31;