From f270af1acd52e01f76295def42302bb8535f9c58 Mon Sep 17 00:00:00 2001
From: Christoph Ruegge <c.ruegge@math.uni-goettingen.de>
Date: Thu, 14 Apr 2016 11:28:10 +0200
Subject: [PATCH 1/2] xsession: Update DBus activation environment

`dbus-launch` is executed early in the script, before desktop managers
had a chance to setup the environment. If DBus activation is used,
applications launched by this may therefore lack necessary environment
variables. This patch sends the complete environment to DBus after
launching the desktop manager.
---
 nixos/modules/services/x11/display-managers/default.nix | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/nixos/modules/services/x11/display-managers/default.nix b/nixos/modules/services/x11/display-managers/default.nix
index be634fc259a..ff78964e553 100644
--- a/nixos/modules/services/x11/display-managers/default.nix
+++ b/nixos/modules/services/x11/display-managers/default.nix
@@ -126,6 +126,14 @@ let
         (*) echo "$0: Desktop manager '$desktopManager' not found.";;
       esac
 
+      ${optionalString cfg.startDbusSession ''
+        ${pkgs.glib}/bin/gdbus call --session \
+          --dest org.freedesktop.DBus --object-path /org/freedesktop/DBus \
+          --method org.freedesktop.DBus.UpdateActivationEnvironment \
+          "{$(env | ${pkgs.gnused}/bin/sed "s/'/\\\\'/g; s/\([^=]*\)=\(.*\)/'\1':'\2'/" \
+                  | ${pkgs.coreutils}/bin/paste -sd,)}"
+      ''}
+
       test -n "$waitPID" && wait "$waitPID"
       exit 0
     '';

From 769a33bedd909dd9f482d9cbb957e400fd3bac88 Mon Sep 17 00:00:00 2001
From: Christoph Ruegge <c.ruegge@math.uni-goettingen.de>
Date: Mon, 25 Apr 2016 23:37:18 +0200
Subject: [PATCH 2/2] xsession: make updating DBus environment optional

---
 nixos/modules/services/x11/desktop-managers/gnome3.nix  | 2 ++
 nixos/modules/services/x11/desktop-managers/xfce.nix    | 5 ++++-
 nixos/modules/services/x11/display-managers/default.nix | 2 +-
 nixos/modules/services/x11/xserver.nix                  | 9 +++++++++
 4 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/nixos/modules/services/x11/desktop-managers/gnome3.nix b/nixos/modules/services/x11/desktop-managers/gnome3.nix
index b112fc2422a..16996b9f96c 100644
--- a/nixos/modules/services/x11/desktop-managers/gnome3.nix
+++ b/nixos/modules/services/x11/desktop-managers/gnome3.nix
@@ -165,6 +165,8 @@ in {
         '';
       };
 
+    services.xserver.updateDbusEnvironment = true;
+
     environment.variables.GIO_EXTRA_MODULES = [ "${gnome3.dconf}/lib/gio/modules"
                                                 "${gnome3.glib_networking.out}/lib/gio/modules"
                                                 "${gnome3.gvfs}/lib/gio/modules" ];
diff --git a/nixos/modules/services/x11/desktop-managers/xfce.nix b/nixos/modules/services/x11/desktop-managers/xfce.nix
index 33b6dd32c19..60934ed5f19 100644
--- a/nixos/modules/services/x11/desktop-managers/xfce.nix
+++ b/nixos/modules/services/x11/desktop-managers/xfce.nix
@@ -42,10 +42,13 @@ in
             # Set GTK_DATA_PREFIX so that GTK+ can find the Xfce themes.
             export GTK_DATA_PREFIX=${config.system.path}
 
-            exec ${pkgs.stdenv.shell} ${pkgs.xfce.xinitrc}
+            ${pkgs.stdenv.shell} ${pkgs.xfce.xinitrc} &
+            waitPID=$!
           '';
       };
 
+    services.xserver.updateDbusEnvironment = true;
+
     environment.systemPackages =
       [ pkgs.gtk # To get GTK+'s themes.
         pkgs.hicolor_icon_theme
diff --git a/nixos/modules/services/x11/display-managers/default.nix b/nixos/modules/services/x11/display-managers/default.nix
index ff78964e553..376f9f4b46b 100644
--- a/nixos/modules/services/x11/display-managers/default.nix
+++ b/nixos/modules/services/x11/display-managers/default.nix
@@ -126,7 +126,7 @@ let
         (*) echo "$0: Desktop manager '$desktopManager' not found.";;
       esac
 
-      ${optionalString cfg.startDbusSession ''
+      ${optionalString (cfg.startDbusSession && cfg.updateDbusEnvironment) ''
         ${pkgs.glib}/bin/gdbus call --session \
           --dest org.freedesktop.DBus --object-path /org/freedesktop/DBus \
           --method org.freedesktop.DBus.UpdateActivationEnvironment \
diff --git a/nixos/modules/services/x11/xserver.nix b/nixos/modules/services/x11/xserver.nix
index dcf9f820f59..9cb9c8de31d 100644
--- a/nixos/modules/services/x11/xserver.nix
+++ b/nixos/modules/services/x11/xserver.nix
@@ -233,6 +233,15 @@ in
         '';
       };
 
+      updateDbusEnvironment = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Whether to update the DBus activation environment after launching the
+          desktop manager.
+        '';
+      };
+
       layout = mkOption {
         type = types.str;
         default = "us";