[gtk/droppable-box-children: 3/4] Make layout managers obey child-visible

[Matthias Clasen <matthiasc src gnome org>]

commit 7eef6b1a0eaa86fc51b8cfaa5b0baa822b1a3694
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Apr 27 19:13:16 2020 -0400

    Make layout managers obey child-visible
    
    Take child-visible into account in addition to visible
    when deciding whether a child should contribute to layout.

 gtk/gtkwidget.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index cf5499b8d4..fc7fb31fa4 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -12318,6 +12318,9 @@ gtk_widget_should_layout (GtkWidget *widget)
   if (!_gtk_widget_get_visible (widget))
     return FALSE;
 
+  if (!_gtk_widget_get_child_visible (widget))
+    return FALSE;
+
   if (GTK_IS_NATIVE (widget))
     return FALSE;