x11/x11-display: Always set the compositor manager selection on init

Set the compositor manager selection during the initialization phase as
we do with the window manager selection

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2970>

3 files changed, 13 insertions, 34 deletions

diff --git a/src/compositor/meta-compositor-x11.c b/src/compositor/meta-compositor-x11.c
index 333cb60f3..bb425c31a 100644
--- a/src/compositor/meta-compositor-x11.c
+++ b/src/compositor/meta-compositor-x11.c
@@ -171,8 +171,6 @@ meta_compositor_x11_manage (MetaCompositor  *compositor,
 
   determine_server_clock_source (compositor_x11);
 
-  meta_x11_display_set_cm_selection (display->x11_display, CurrentTime);
-
   compositor_x11->output = display->x11_display->composite_overlay_window;
 
   xwindow = meta_backend_x11_get_xwindow (META_BACKEND_X11 (backend));
diff --git a/src/x11/meta-x11-display-private.h b/src/x11/meta-x11-display-private.h
index ef9c7e11a..8f9ec1e6e 100644
--- a/src/x11/meta-x11-display-private.h
+++ b/src/x11/meta-x11-display-private.h
@@ -292,9 +292,6 @@ int meta_x11_display_get_screen_number (MetaX11Display *x11_display);
 
 int meta_x11_display_get_damage_event_base (MetaX11Display *x11_display);
 
-void meta_x11_display_set_cm_selection (MetaX11Display *x11_display,
-                                        uint32_t        timestamp);
-
 gboolean meta_x11_display_xwindow_is_a_no_focus_window (MetaX11Display *x11_display,
                                                         Window xwindow);
 
diff --git a/src/x11/meta-x11-display.c b/src/x11/meta-x11-display.c
index 903309269..a1048f56e 100644
--- a/src/x11/meta-x11-display.c
+++ b/src/x11/meta-x11-display.c
@@ -1166,6 +1166,7 @@ meta_x11_display_new (MetaDisplay  *display,
   Window new_wm_sn_owner;
   gboolean replace_current_wm;
   Atom wm_sn_atom;
+  Atom wm_cm_atom;
   char buf[128];
   guint32 timestamp;
   Atom atom_restart_helper;
@@ -1434,21 +1435,21 @@ meta_x11_display_new (MetaDisplay  *display,
   x11_display->wm_sn_atom = wm_sn_atom;
   x11_display->wm_sn_timestamp = timestamp;
 
-#ifdef HAVE_XWAYLAND
-  if (meta_is_wayland_compositor ())
-    {
-      meta_x11_display_set_cm_selection (x11_display, timestamp);
+  g_snprintf (buf, sizeof (buf), "_NET_WM_CM_S%d", number);
+  wm_cm_atom = XInternAtom (x11_display->xdisplay, buf, False);
 
-      if (x11_display->wm_cm_selection_window == None)
-        {
-          g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
-                       "Failed to acquire compositor ownership");
+  x11_display->wm_cm_selection_window =
+    take_manager_selection (x11_display, xroot, wm_cm_atom, timestamp,
+                            replace_current_wm);
 
-          g_object_run_dispose (G_OBJECT (x11_display));
-          return NULL;
-        }
+  if (x11_display->wm_cm_selection_window == None)
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "Failed to acquire compositor ownership");
+
+      g_object_run_dispose (G_OBJECT (x11_display));
+      return NULL;
     }
-#endif
 
   init_event_masks (x11_display);
 
@@ -1873,23 +1874,6 @@ on_monitors_changed_internal (MetaMonitorManager *monitor_manager,
   x11_display->has_xinerama_indices = FALSE;
 }
 
-void
-meta_x11_display_set_cm_selection (MetaX11Display *x11_display,
-                                   uint32_t        timestamp)
-{
-  char selection[32];
-  Atom a;
-
-  if (timestamp == CurrentTime)
-    timestamp = meta_x11_display_get_current_time_roundtrip (x11_display);
-
-  g_snprintf (selection, sizeof (selection), "_NET_WM_CM_S%d",
-              DefaultScreen (x11_display->xdisplay));
-  a = XInternAtom (x11_display->xdisplay, selection, False);
-
-  x11_display->wm_cm_selection_window = take_manager_selection (x11_display, x11_display->xroot, a, timestamp, TRUE);
-}
-
 static Bool
 find_timestamp_predicate (Display  *xdisplay,
                           XEvent   *ev,