From 1b743526bdb3e1bd231a378597f12133ea8fb320 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Wed, 25 Jul 2012 09:27:51 -0400
Subject: [PATCH] grub.nix: Handle null values

http://hydra.nixos.org/build/2894714
---
 modules/installer/grub/grub.nix | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/modules/installer/grub/grub.nix b/modules/installer/grub/grub.nix
index c4bb3bd16cb..3a76e08f26a 100644
--- a/modules/installer/grub/grub.nix
+++ b/modules/installer/grub/grub.nix
@@ -8,9 +8,11 @@ let
 
   grub = if cfg.version == 1 then pkgs.grub else pkgs.grub2;
 
+  f = x: if x == null then "" else "" + x;
+
   grubConfig = pkgs.writeText "grub-config.xml" (builtins.toXML
-    { splashImage = "" + config.boot.loader.grub.splashImage;
-      grub = "" + grub;
+    { splashImage = f config.boot.loader.grub.splashImage;
+      grub = f grub;
       inherit (config.boot.loader.grub)
         version extraConfig extraPerEntryConfig extraEntries
         extraEntriesBeforeNixOS configurationLimit copyKernels timeout