ir_to_mesa: Allow ir_return in main().

I didn't expect that this would really work, but it turns out there
are shaders in the wild that do it.

Fixes: (with swrast)
glsl-fs-main-return
glsl-vs-main-return

diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp
index 7b65fa4..7de1939 100644 (file)
--- a/src/mesa/program/ir_to_mesa.cpp
+++ b/src/mesa/program/ir_to_mesa.cpp
@@ -2129,12 +2129,12 @@ ir_to_mesa_visitor::visit(ir_texture *ir)
 void
 ir_to_mesa_visitor::visit(ir_return *ir)
 {
-   assert(current_function);
-
    if (ir->get_value()) {
       ir_to_mesa_dst_reg l;
       int i;
 
+      assert(current_function);
+
       ir->get_value()->accept(this);
       ir_to_mesa_src_reg r = this->result;