From 0dfb94dbdf05f5dbf7918533e9cf3d0d970e3014 Mon Sep 17 00:00:00 2001
From: K900 <me@0upti.me>
Date: Tue, 27 Aug 2024 19:45:47 +0300
Subject: [PATCH 1/3] nixos/sddm: remove LANG=C.UTF-8

Not sure why that was there but it's evidently not necessary.
---
 nixos/modules/services/display-managers/sddm.nix | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/nixos/modules/services/display-managers/sddm.nix b/nixos/modules/services/display-managers/sddm.nix
index 54356f7bb6171..a356c550f5d8a 100644
--- a/nixos/modules/services/display-managers/sddm.nix
+++ b/nixos/modules/services/display-managers/sddm.nix
@@ -44,10 +44,7 @@ let
 
       DisplayServer = if cfg.wayland.enable then "wayland" else "x11";
     } // optionalAttrs (cfg.wayland.compositor == "kwin") {
-      GreeterEnvironment = concatStringsSep " " [
-        "LANG=C.UTF-8"
-        "QT_WAYLAND_SHELL_INTEGRATION=layer-shell"
-      ];
+      GreeterEnvironment = "QT_WAYLAND_SHELL_INTEGRATION=layer-shell";
       InputMethod = ""; # needed if we are using --inputmethod with kwin
     };
 

From 094e80f6ff07705d9f4ace748029265647eeb4df Mon Sep 17 00:00:00 2001
From: K900 <me@0upti.me>
Date: Tue, 27 Aug 2024 20:14:23 +0300
Subject: [PATCH 2/3] nixos/sddm: don't set kwin related config if Wayland
 isn't enabled

---
 nixos/modules/services/display-managers/sddm.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nixos/modules/services/display-managers/sddm.nix b/nixos/modules/services/display-managers/sddm.nix
index a356c550f5d8a..711d5c439fc6b 100644
--- a/nixos/modules/services/display-managers/sddm.nix
+++ b/nixos/modules/services/display-managers/sddm.nix
@@ -43,7 +43,7 @@ let
       DefaultSession = optionalString (config.services.displayManager.defaultSession != null) "${config.services.displayManager.defaultSession}.desktop";
 
       DisplayServer = if cfg.wayland.enable then "wayland" else "x11";
-    } // optionalAttrs (cfg.wayland.compositor == "kwin") {
+    } // optionalAttrs (cfg.wayland.enable && cfg.wayland.compositor == "kwin") {
       GreeterEnvironment = "QT_WAYLAND_SHELL_INTEGRATION=layer-shell";
       InputMethod = ""; # needed if we are using --inputmethod with kwin
     };

From 363df5ad86ddad600a69694d472b1328c53ac9ab Mon Sep 17 00:00:00 2001
From: K900 <me@0upti.me>
Date: Tue, 27 Aug 2024 20:15:00 +0300
Subject: [PATCH 3/3] nixos/sddm: add layer-shell-qt to the wrapper when kwin
 is used

Otherwise the greeter just dies immediately.
---
 nixos/modules/services/display-managers/sddm.nix    | 1 +
 pkgs/applications/display-managers/sddm/default.nix | 6 +++++-
 pkgs/top-level/qt6-packages.nix                     | 2 +-
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/nixos/modules/services/display-managers/sddm.nix b/nixos/modules/services/display-managers/sddm.nix
index 711d5c439fc6b..ca46d627101ad 100644
--- a/nixos/modules/services/display-managers/sddm.nix
+++ b/nixos/modules/services/display-managers/sddm.nix
@@ -8,6 +8,7 @@ let
 
   sddm = cfg.package.override (old: {
     withWayland = cfg.wayland.enable;
+    withLayerShellQt = cfg.wayland.compositor == "kwin";
     extraPackages = old.extraPackages or [ ] ++ cfg.extraPackages;
   });
 
diff --git a/pkgs/applications/display-managers/sddm/default.nix b/pkgs/applications/display-managers/sddm/default.nix
index 45268ae44bdfd..451317fae2681 100644
--- a/pkgs/applications/display-managers/sddm/default.nix
+++ b/pkgs/applications/display-managers/sddm/default.nix
@@ -2,16 +2,20 @@
   lib,
   callPackage,
   runCommand,
+  layer-shell-qt,
   qtwayland,
   wrapQtAppsHook,
   unwrapped ? callPackage ./unwrapped.nix {},
   withWayland ? false,
+  withLayerShellQt ? false,
   extraPackages ? [],
 }:
 runCommand "sddm-wrapped" {
   inherit (unwrapped) version;
 
-  buildInputs = unwrapped.buildInputs ++ extraPackages ++ lib.optional withWayland qtwayland;
+  buildInputs = unwrapped.buildInputs ++ extraPackages
+    ++ lib.optional withWayland qtwayland
+    ++ lib.optional (withWayland && withLayerShellQt) layer-shell-qt;
   nativeBuildInputs = [ wrapQtAppsHook ];
 
   passthru = {
diff --git a/pkgs/top-level/qt6-packages.nix b/pkgs/top-level/qt6-packages.nix
index aab6797832248..f63e2245b59b4 100644
--- a/pkgs/top-level/qt6-packages.nix
+++ b/pkgs/top-level/qt6-packages.nix
@@ -104,7 +104,7 @@ makeScopeWithSplicing' {
 
   # Not a library, but we do want it to be built for every qt version there
   # is, to allow users to choose the right build if needed.
-  sddm = callPackage ../applications/display-managers/sddm {};
+  sddm = kdePackages.callPackage ../applications/display-managers/sddm {};
 
   sierra-breeze-enhanced = kdePackages.callPackage ../data/themes/kwin-decorations/sierra-breeze-enhanced { };