mesa: additional case in file_string()
diff --git a/src/mesa/shader/prog_print.c b/src/mesa/shader/prog_print.c
index 9215ed7..0ec13a4 100644
--- a/src/mesa/shader/prog_print.c
+++ b/src/mesa/shader/prog_print.c
@@ -71,6 +71,8 @@
       return "ADDR";
    case PROGRAM_SAMPLER:
       return "SAMPLER";
+   case PROGRAM_UNDEFINED:
+      return "UNDEFINED";
    default:
       return "Unknown program file!";
    }