[mutter/gnome-3-36] x11: Forward current selection state when initializing X11 selections

[Robert Mader <rmader src gnome org>]

commit ac8075bbf5d6c6cecd4ca08027e91a10c5c17074
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed Apr 8 13:37:19 2020 +0200

    x11: Forward current selection state when initializing X11 selections
    
    Most visible with xwayland-on-demand, at the time of setting things up
    for X11 selections, we don't forward the current state. This makes the
    first started X11 app oblivious to eg. the current clipboard.
    
    Syncing selections up at the time of initializing the X11 selection
    stuff ensures that doesn't happen.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1186
    
    (cherry picked from commit 167fd07e010e25feb7ff195706bf91d7c70d1273)

 src/x11/meta-x11-selection.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)
---
diff --git a/src/x11/meta-x11-selection.c b/src/x11/meta-x11-selection.c
index a93fa1585..24a075b58 100644
--- a/src/x11/meta-x11-selection.c
+++ b/src/x11/meta-x11-selection.c
@@ -23,6 +23,7 @@
 
 #include <gdk/gdkx.h>
 
+#include "core/meta-selection-private.h"
 #include "x11/meta-selection-source-x11-private.h"
 #include "x11/meta-x11-selection-output-stream-private.h"
 #include "x11/meta-x11-selection-private.h"
@@ -374,10 +375,9 @@ meta_x11_selection_handle_event (MetaX11Display *x11_display,
 }
 
 static void
-owner_changed_cb (MetaSelection       *selection,
-                  MetaSelectionType    selection_type,
-                  MetaSelectionSource *new_owner,
-                  MetaX11Display      *x11_display)
+notify_selection_owner (MetaX11Display      *x11_display,
+                        MetaSelectionType    selection_type,
+                        MetaSelectionSource *new_owner)
 {
   Display *xdisplay = x11_display->xdisplay;
 
@@ -404,6 +404,7 @@ meta_x11_selection_init (MetaX11Display *x11_display)
 {
   XSetWindowAttributes attributes = { 0 };
   MetaDisplay *display = meta_get_display ();
+  MetaSelection *selection;
   guint mask, i;
 
   attributes.event_mask = PropertyChangeMask | SubstructureNotifyMask;
@@ -424,18 +425,24 @@ meta_x11_selection_init (MetaX11Display *x11_display)
     XFixesSelectionWindowDestroyNotifyMask |
     XFixesSelectionClientCloseNotifyMask;
 
+  selection = meta_display_get_selection (display);
+
   for (i = 0; i < META_N_SELECTION_TYPES; i++)
     {
+      MetaSelectionSource *owner;
+
       XFixesSelectSelectionInput (x11_display->xdisplay,
                                   x11_display->selection.xwindow,
                                   selection_to_atom (i, x11_display->xdisplay),
                                   mask);
+      owner = meta_selection_get_current_owner (selection, i);
+      notify_selection_owner (x11_display, i, owner);
     }
 
-  g_signal_connect (meta_display_get_selection (display),
-                    "owner-changed",
-                    G_CALLBACK (owner_changed_cb),
-                    x11_display);
+  g_signal_connect_swapped (selection,
+                            "owner-changed",
+                            G_CALLBACK (notify_selection_owner),
+                            x11_display);
 }
 
 void
@@ -445,7 +452,7 @@ meta_x11_selection_shutdown (MetaX11Display *x11_display)
   guint i;
 
   g_signal_handlers_disconnect_by_func (meta_display_get_selection (display),
-                                        owner_changed_cb,
+                                        notify_selection_owner,
                                         x11_display);
 
   for (i = 0; i < META_N_SELECTION_TYPES; i++)