r300/compiler: Assert that array index is not negative.

diff --git a/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c b/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c
index 829f028950c99b191d4a46156004d6e2e49b9c84..710cae727a1a321b7874462251505dc18ebf7b59 100644 (file)
--- a/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c
+++ b/src/mesa/drivers/dri/r300/compiler/r500_fragprog_emit.c
@@ -469,6 +469,8 @@ void r500BuildFragmentProgramHwCode(struct r300_fragment_program_compiler *compi
        if (compiler->Base.Error)
                return;
 
+       assert(code->inst_end >= 0);
+
        if ((code->inst[code->inst_end].inst0 & R500_INST_TYPE_MASK) != R500_INST_TYPE_OUT) {
                /* This may happen when dead-code elimination is disabled or
                 * when most of the fragment program logic is leading to a KIL */