Merge pull request #41486 from grahamc/support-null-font

grub: Support when boot.loader.grub.font is null

nixos/modules/system/boot/loader/grub/grub.nix

···
       )) + ":" + (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; }) {}

nixos/modules/system/boot/loader/grub/install-grub.pl

···
         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.