[gtk/matthiasc/surface-state-rework: 26/80] gtk/dragicon: Don't show until child is set

[Matthias Clasen <matthiasc src gnome org>]

commit 1bbc9d72e9392a6f6a29a9a7a59c48067505c8fd
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Nov 25 15:02:26 2020 +0100

    gtk/dragicon: Don't show until child is set
    
    Showing before the child would result in bogus
    gdk_drag_surface_present() with an "empty" (1x1) size. This can easily
    be avoided by postponing showing until there is anything to show.

 gtk/gtkdragicon.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkdragicon.c b/gtk/gtkdragicon.c
index 2348674951..e239090011 100644
--- a/gtk/gtkdragicon.c
+++ b/gtk/gtkdragicon.c
@@ -414,7 +414,8 @@ gtk_drag_icon_get_for_drag (GdkDrag *drag)
 
       g_object_set_qdata_full (G_OBJECT (drag), drag_icon_quark, g_object_ref_sink (self), g_object_unref);
 
-      gtk_widget_show (self);
+      if (GTK_DRAG_ICON (self)->child != NULL)
+        gtk_widget_show (self);
     }
 
   return self;
@@ -472,7 +473,10 @@ gtk_drag_icon_set_child (GtkDragIcon *self,
   self->child = child;
 
   if (self->child)
-    gtk_widget_set_parent (self->child, GTK_WIDGET (self));
+    {
+      gtk_widget_set_parent (self->child, GTK_WIDGET (self));
+      gtk_widget_show (GTK_WIDGET (self));
+    }
 
   g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_CHILD]);
 }