From b5168a9900ec8943ad9a7778bd2935f69f17703b Mon Sep 17 00:00:00 2001
From: Jonathan Ringer <jonringer117@gmail.com>
Date: Tue, 26 Nov 2024 21:18:21 +0200
Subject: [PATCH] nixos/iso-image: fix `isoImage.grubTheme = null;`

Fixes `error: cannot coerce null to a string`
---
 nixos/modules/installer/cd-dvd/iso-image.nix | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/installer/cd-dvd/iso-image.nix b/nixos/modules/installer/cd-dvd/iso-image.nix
index 63abf88cab09..cf2cdb8eecef 100644
--- a/nixos/modules/installer/cd-dvd/iso-image.nix
+++ b/nixos/modules/installer/cd-dvd/iso-image.nix
@@ -335,12 +335,14 @@ let
       set textmode=true
       terminal_output console
     }
+
+    ${lib.optionalString (config.isoImage.grubTheme != null) ''
     hiddenentry 'GUI mode' --hotkey 'g' {
       $(find ${config.isoImage.grubTheme} -iname '*.pf2' -printf "loadfont (\$root)/EFI/BOOT/grub-theme/%P\n")
       set textmode=false
       terminal_output gfxterm
     }
-
+    ''}
 
     # If the parameter iso_path is set, append the findiso parameter to the kernel
     # line. We need this to allow the nixos iso to be booted from grub directly.