Index: /trunk/src/VBox/Devices/Graphics/shaderlib/glsl_shader.c
===================================================================
--- /trunk/src/VBox/Devices/Graphics/shaderlib/glsl_shader.c	(revision 83625)
+++ /trunk/src/VBox/Devices/Graphics/shaderlib/glsl_shader.c	(revision 83626)
@@ -1632,5 +1632,6 @@
 
         case WINED3DSPR_RASTOUT:
-            sprintf(register_name, "%s", hwrastout_reg_names[reg->idx]);
+            if (reg->idx < RT_ELEMENTS(hwrastout_reg_names)) sprintf(register_name, "%s", hwrastout_reg_names[reg->idx]);
+            else sprintf(register_name, "%s", hwrastout_reg_names[0]);
             break;