[gdm] daemon: support dbus user buses with X sessions

[Ray Strode <halfline src gnome org>]

commit 99eeae91c1f11997521ad3bc016a7b2d23ec7942
Author: Ray Strode <rstrode redhat com>
Date:   Thu Feb 4 13:36:06 2016 -0500

    daemon: support dbus user buses with X sessions
    
    If the dbus user bus was started when the user first
    logged in, before the session was started, then that
    dbus daemon won't have DISPLAY and XAUTHORITY in its
    activation environment.
    
    This means programs activated from that dbus daemon
    also won't have DISPLAY and XAUTHORITY in their
    activation environments.
    
    This commit changes GDM to explicitly put the two
    variables in the activation environment via D-Bus,
    rather than sending them into the bus environment
    process when launching the bus (since in the case
    of the user bus, we don't launch it).
    
    https://bugzilla.gnome.org/show_bug.cgi?id=761568

 daemon/gdm-x-session.c |   42 +++++++++++++++++++++++++++++++++++++++---
 1 files changed, 39 insertions(+), 3 deletions(-)
---
diff --git a/daemon/gdm-x-session.c b/daemon/gdm-x-session.c
index 624f67c..c01cc5e 100644
--- a/daemon/gdm-x-session.c
+++ b/daemon/gdm-x-session.c
@@ -378,6 +378,9 @@ spawn_bus (State        *state,
         GSubprocess         *subprocess = NULL;
         GInputStream        *input_stream = NULL;
         GDataInputStream    *data_stream = NULL;
+        GDBusConnection     *connection = NULL;
+        GVariantBuilder     *builder = NULL;
+        GVariant            *reply = NULL;
         GError              *error = NULL;
         const char          *bus_env = NULL;
         char                *bus_address_fd_string;
@@ -407,9 +410,6 @@ spawn_bus (State        *state,
         arguments = g_ptr_array_new ();
         launcher = g_subprocess_launcher_new (G_SUBPROCESS_FLAGS_NONE);
 
-        g_subprocess_launcher_setenv (launcher, "DISPLAY", state->display_name, TRUE);
-        g_subprocess_launcher_setenv (launcher, "XAUTHORITY", state->auth_file, TRUE);
-
         g_subprocess_launcher_take_fd (launcher, pipe_fds[1], BUS_ADDRESS_FILENO);
 
         bus_address_fd_string = g_strdup_printf ("%d", BUS_ADDRESS_FILENO);
@@ -462,6 +462,42 @@ spawn_bus (State        *state,
                                  on_bus_finished,
                                  state);
 
+        connection = g_dbus_connection_new_for_address_sync (state->bus_address,
+                                                             G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT |
+                                                             G_DBUS_CONNECTION_FLAGS_MESSAGE_BUS_CONNECTION,
+                                                             NULL,
+                                                             cancellable,
+                                                             &error);
+
+        if (connection == NULL) {
+                g_debug ("could not open connection to session bus: %s",
+                         error->message);
+                goto out;
+        }
+
+        g_variant_builder_init (&builder, G_VARIANT_TYPE ("a{ss}"));
+        g_variant_builder_add (&builder, "{ss}", "DISPLAY", state->display_name);
+        g_variant_builder_add (&builder, "{ss}", "XAUTHORITY", state->auth_file);
+
+        reply = g_dbus_connection_call_sync (connection,
+                                             "org.freedesktop.DBus",
+                                             "/org/freedesktop/DBus",
+                                             "org.freedesktop.DBus",
+                                             "UpdateActivationEnvironment",
+                                             g_variant_new ("(@a{ss})",
+                                                            g_variant_builder_end (&builder)),
+                                             NULL,
+                                             G_DBUS_CALL_FLAGS_NONE,
+                                             -1, NULL, &error);
+
+        if (reply == NULL) {
+                g_debug ("could not update activation environment: %s", error->message);
+                goto out;
+        }
+
+        g_variant_unref (reply);
+        g_clear_object (&connection);
+
         is_running = TRUE;
 out:
         g_clear_object (&data_stream);