From 52de38f5f40a97dc46bbb9a442903f26e087bd30 Mon Sep 17 00:00:00 2001
From: Graham Christensen <graham@grahamc.com>
Date: Tue, 5 Jun 2018 10:37:12 -0400
Subject: [PATCH 1/2] grub-config.xml: handle a null font

---
 nixos/modules/system/boot/loader/grub/grub.nix | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/nixos/modules/system/boot/loader/grub/grub.nix b/nixos/modules/system/boot/loader/grub/grub.nix
index 67daaa333e5edd..2e497ff9f2c495 100644
--- a/nixos/modules/system/boot/loader/grub/grub.nix
+++ b/nixos/modules/system/boot/loader/grub/grub.nix
@@ -64,9 +64,10 @@ let
       )) + ":" + (makeSearchPathOutput "bin" "sbin" [
         pkgs.mdadm pkgs.utillinux
       ]);
-      font = if lib.last (lib.splitString "." cfg.font) == "pf2"
+      font = if cfg.font == null then ""
+        else (if lib.last (lib.splitString "." cfg.font) == "pf2"
              then cfg.font
-             else "${convertedFont}";
+             else "${convertedFont}");
     });
 
   bootDeviceCounters = fold (device: attr: attr // { "${device}" = (attr."${device}" or 0) + 1; }) {}

From ab889c14b5228fbb1d76f61bfa9bb07558ca053c Mon Sep 17 00:00:00 2001
From: Graham Christensen <graham@grahamc.com>
Date: Tue, 5 Jun 2018 10:37:38 -0400
Subject: [PATCH 2/2] install-grub: only try to loadfont if font is not null

---
 .../system/boot/loader/grub/install-grub.pl   | 26 ++++++++++---------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/nixos/modules/system/boot/loader/grub/install-grub.pl b/nixos/modules/system/boot/loader/grub/install-grub.pl
index 1aa14729a75cbd..872261d0edfa82 100644
--- a/nixos/modules/system/boot/loader/grub/install-grub.pl
+++ b/nixos/modules/system/boot/loader/grub/install-grub.pl
@@ -281,22 +281,24 @@ sub GrubFs {
         else
           insmod vbe
         fi
-        insmod font
-        if loadfont " . $grubBoot->path . "/converted-font.pf2; then
-          insmod gfxterm
-          if [ \"\${grub_platform}\" = \"efi\" ]; then
-            set gfxmode=$gfxmodeEfi
-            set gfxpayload=keep
-          else
-            set gfxmode=$gfxmodeBios
-            set gfxpayload=text
-          fi
-          terminal_output gfxterm
-        fi
     ";
 
     if ($font) {
         copy $font, "$bootPath/converted-font.pf2" or die "cannot copy $font to $bootPath\n";
+        $conf .= "
+            insmod font
+            if loadfont " . $grubBoot->path . "/converted-font.pf2; then
+              insmod gfxterm
+              if [ \"\${grub_platform}\" = \"efi\" ]; then
+                set gfxmode=$gfxmodeEfi
+                set gfxpayload=keep
+              else
+                set gfxmode=$gfxmodeBios
+                set gfxpayload=text
+              fi
+              terminal_output gfxterm
+            fi
+        ";
     }
     if ($splashImage) {
         # Keeps the image's extension.