fix tempReg test in _mesa_combine_programs()

diff --git a/src/mesa/shader/program.c b/src/mesa/shader/program.c
index 044d644..7048770 100644 (file)
--- a/src/mesa/shader/program.c
+++ b/src/mesa/shader/program.c
@@ -641,7 +641,7 @@ _mesa_combine_programs(GLcontext *ctx,
       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;