nixos/console: fix optimizedKeymap derivation isUnicode condition (#467132)

nixos/modules/config/console.nix

@@ -9,7 +9,7 @@ let
 
   makeColor = i: lib.concatMapStringsSep "," (x: "0x" + lib.substring (2 * i) 2 x);
 
-  isUnicode = lib.hasSuffix "UTF-8" (lib.toUpper config.i18n.defaultLocale);
+  isUnicode = config.i18n.defaultCharset == "UTF-8" || cfg.useXkbConfig;
 
   optimizedKeymap =
     pkgs.runCommand "keymap"

nixos/tests/all-tests.nix

@@ -386,6 +386,7 @@ in
   collectd = runTest ./collectd.nix;
   commafeed = runTest ./commafeed.nix;
   connman = runTest ./connman.nix;
+  console-xkb-and-i18n = runTest ./console-xkb-and-i18n.nix;
   consul = runTest ./consul.nix;
   consul-template = runTest ./consul-template.nix;
   containers-bridge = runTest ./containers-bridge.nix;

nixos/tests/console-xkb-and-i18n.nix

@@ -0,0 +1,23 @@
+{ lib, ... }:
+{
+  name = "console-xkb-and-i18n";
+  meta.maintainers = with lib.maintainers; [ doronbehar ];
+
+  nodes = {
+    # Nothing to run on this node. Only verify that this configuration doesn't
+    # produce the bugs described here:
+    #
+    # - https://github.com/NixOS/nixpkgs/issues/445666
+    # - https://github.com/NixOS/nixpkgs/issues/411374
+    #
+    x = {
+      i18n.defaultLocale = "eo";
+      console.useXkbConfig = true;
+      services.xserver.xkb = {
+        layout = "us";
+        variant = "colemak";
+      };
+    };
+  };
+  testScript = { nodes, ... }: "";
+}