[mutter/benzea/xwayland-non-systemd-startup] xwayland: Start Xwayland for services and never stop on non-systemd

[Benjamin Berg <bberg src gnome org>]

commit acd2551bbba3c31c0b672a971adee3c6efcf828e
Author: Benjamin Berg <bberg redhat com>
Date:   Thu Mar 11 11:23:55 2021 +0100

    xwayland: Start Xwayland for services and never stop on non-systemd
    
    The (gnome-shell) handling to start the X11 related services (i.e.
    gsd-xsettings) requires running in a systemd managed session. If this is
    not the case, we must start Xwayland already for gsd-xsettings and we
    cannot auto-shutdown Xwayland.
    
    As such, we get three common cases:
     * Fully working Xwayland on demand on systemd
     * gsd-xsettings starting Xwayland immediately at login time
       (this is currently the case for the gnome-initial-setup session)
     * Xwayland remaining dormand as nothing ever requires it
       (this is the case for the GDM greeter)

 src/wayland/meta-wayland.c  | 11 ++++++++++-
 src/wayland/meta-xwayland.c |  7 +++++++
 2 files changed, 17 insertions(+), 1 deletion(-)
---
diff --git a/src/wayland/meta-wayland.c b/src/wayland/meta-wayland.c
index b032a8bfce..787ec91f73 100644
--- a/src/wayland/meta-wayland.c
+++ b/src/wayland/meta-wayland.c
@@ -28,6 +28,8 @@
 #include <stdlib.h>
 #include <wayland-server.h>
 
+#include <systemd/sd-login.h>
+
 #include "clutter/clutter.h"
 #include "clutter/wayland/clutter-wayland-compositor.h"
 #include "compositor/meta-surface-actor-wayland.h"
@@ -470,6 +472,7 @@ meta_wayland_compositor_setup (MetaWaylandCompositor *compositor)
 {
   ClutterActor *stage = meta_backend_get_stage (compositor->backend);
   GSource *wayland_event_source;
+  MetaDisplayPolicy policy;
 
   wayland_event_source = wayland_event_source_new (compositor->wayland_display);
 
@@ -557,7 +560,13 @@ meta_wayland_compositor_setup (MetaWaylandCompositor *compositor)
 
   if (meta_get_x11_display_policy () != META_DISPLAY_POLICY_DISABLED)
     {
-      set_gnome_env ("GNOME_SETUP_DISPLAY", compositor->xwayland_manager.private_connection.name);
+      g_autofree char *unit = NULL;
+
+      /* On non-systemd, we need to start-up for the services,
+       * so don't set GNOME_SETUP_DISPLAY to the private connection.
+       */
+      if (sd_pid_get_user_unit (0, &unit) >= 0)
+        set_gnome_env ("GNOME_SETUP_DISPLAY", compositor->xwayland_manager.private_connection.name);
       set_gnome_env ("DISPLAY", compositor->xwayland_manager.public_connection.name);
       set_gnome_env ("XAUTHORITY", meta_wayland_get_xwayland_auth_file (compositor));
     }
diff --git a/src/wayland/meta-xwayland.c b/src/wayland/meta-xwayland.c
index 48fabbfb33..88c1aad557 100644
--- a/src/wayland/meta-xwayland.c
+++ b/src/wayland/meta-xwayland.c
@@ -45,6 +45,8 @@
 
 #include <xcb/res.h>
 
+#include <systemd/sd-login.h>
+
 #include "backends/meta-monitor-manager-private.h"
 #include "backends/meta-settings-private.h"
 #include "core/main-private.h"
@@ -577,6 +579,11 @@ shutdown_xwayland_cb (gpointer data)
   MetaXWaylandManager *manager = data;
   MetaDisplay *display = meta_get_display ();
   MetaBackend *backend = meta_get_backend ();
+  g_autofree char* unit = NULL;
+
+  /* Never shutdown on non-systemd */
+  if (sd_pid_get_user_unit (0, &unit) < 0)
+    return G_SOURCE_REMOVE;
 
   if (!meta_settings_is_experimental_feature_enabled (meta_backend_get_settings (backend),
                                                       META_EXPERIMENTAL_FEATURE_AUTOCLOSE_XWAYLAND))