[gtk/wip/matthiasc/popup5: 7/75] widget: Don't snapshot foreign children

[Matthias Clasen <matthiasc src gnome org>]

commit 7401cada68faaba4e0ddd1471295fb610ea63896
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Mar 18 07:51:47 2019 -0400

    widget: Don't snapshot foreign children
    
    When snapshotting, we walk down the widget tree.
    We need to skip children that have a different
    surface, since those will do their own snapshot.

 gtk/gtkwidget.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 391236f5b5..8e8f541b13 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -70,6 +70,7 @@
 #include "gtkwidgetpathprivate.h"
 #include "gtkwindowgroup.h"
 #include "gtkwindowprivate.h"
+#include "gtknativeprivate.h"
 
 #include "a11y/gtkwidgetaccessible.h"
 #include "inspector/window.h"
@@ -13430,6 +13431,8 @@ gtk_widget_forall (GtkWidget   *widget,
  *
  * gtk_widget_snapshot_child() takes care of translating the origin of
  * @snapshot, and deciding whether the child needs to be snapshot.
+ *
+ * This function does nothing for children that implement #GtkNative.
  **/
 void
 gtk_widget_snapshot_child (GtkWidget   *widget,
@@ -13441,6 +13444,9 @@ gtk_widget_snapshot_child (GtkWidget   *widget,
   g_return_if_fail (_gtk_widget_get_parent (child) == widget);
   g_return_if_fail (snapshot != NULL);
 
+  if (GTK_IS_NATIVE (child))
+    return;
+
   gtk_snapshot_save (snapshot);
   gtk_snapshot_transform (snapshot, priv->transform);