nixos/mate: make the session work without display managers

nixos/modules/services/x11/desktop-managers/mate.nix

@@ -4,17 +4,6 @@ with lib;
 
 let
 
-  addToXDGDirs = p: ''
-    if [ -d "${p}/share/gsettings-schemas/${p.name}" ]; then
-      export XDG_DATA_DIRS=$XDG_DATA_DIRS''${XDG_DATA_DIRS:+:}${p}/share/gsettings-schemas/${p.name}
-    fi
-
-    if [ -d "${p}/lib/girepository-1.0" ]; then
-      export GI_TYPELIB_PATH=$GI_TYPELIB_PATH''${GI_TYPELIB_PATH:+:}${p}/lib/girepository-1.0
-      export LD_LIBRARY_PATH=$LD_LIBRARY_PATH''${LD_LIBRARY_PATH:+:}${p}/lib
-    fi
-  '';
-
   xcfg = config.services.xserver;
   cfg = xcfg.desktopManager.mate;
 
@@ -48,24 +37,8 @@ in
       pkgs.mate.mate-session-manager
     ];
 
-    services.xserver.displayManager.sessionCommands = ''
-      if test "$XDG_CURRENT_DESKTOP" = "MATE"; then
-          export XDG_MENU_PREFIX=mate-
-
-          # Let caja find extensions
-          export CAJA_EXTENSION_DIRS=$CAJA_EXTENSION_DIRS''${CAJA_EXTENSION_DIRS:+:}${config.system.path}/lib/caja/extensions-2.0
-
-          # Let caja extensions find gsettings schemas
-          ${concatMapStrings (p: ''
-          if [ -d "${p}/lib/caja/extensions-2.0" ]; then
-              ${addToXDGDirs p}
-          fi
-          '') config.environment.systemPackages}
-
-          # Add mate-control-center paths to some XDG variables because its schemas are needed by mate-settings-daemon, and mate-settings-daemon is a dependency for mate-control-center (that is, they are mutually recursive)
-          ${addToXDGDirs pkgs.mate.mate-control-center}
-      fi
-    '';
+    # Let caja find extensions
+    environment.sessionVariables.CAJA_EXTENSION_DIRS = [ "${config.system.path}/lib/caja/extensions-2.0" ];
 
     # Let mate-panel find applets
     environment.sessionVariables."MATE_PANEL_APPLETS_DIR" = "${config.system.path}/share/mate-panel/applets";
@@ -83,7 +56,6 @@ in
         pkgs.gtk3.out
         pkgs.shared-mime-info
         pkgs.xdg-user-dirs # Update user dirs as described in https://freedesktop.org/wiki/Software/xdg-user-dirs/
-        pkgs.mate.mate-settings-daemon
         pkgs.yelp # for 'Contents' in 'Help' menus
       ])
       config.environment.mate.excludePackages;