[gtk/matthiasc/for-master] listview: Avoid a critical when reordering

[Matthias Clasen <matthiasc src gnome org>]

commit 9fde0137a052ebdb0374a1303a70517cd43afa72
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Sep 23 22:53:21 2020 -0400

    listview: Avoid a critical when reordering
    
    When sorting a cell into the place its already at,
    we were triggering criticals. Avoid that.
    
    Fixes: #3180

 gtk/gtklistitemwidget.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)
---
diff --git a/gtk/gtklistitemwidget.c b/gtk/gtklistitemwidget.c
index 5c57d1b257..ce4f505039 100644
--- a/gtk/gtklistitemwidget.c
+++ b/gtk/gtklistitemwidget.c
@@ -629,10 +629,13 @@ gtk_list_item_widget_reorder_child (GtkListItemWidget *self,
         }
     }
 
-  gtk_widget_insert_after (child, widget, sibling);
-  gtk_css_node_insert_after (gtk_widget_get_css_node (widget),
-                             gtk_widget_get_css_node (child),
-                             sibling ? gtk_widget_get_css_node (sibling) : NULL);
+  if (child != sibling)
+    {
+      gtk_widget_insert_after (child, widget, sibling);
+      gtk_css_node_insert_after (gtk_widget_get_css_node (widget),
+                                 gtk_widget_get_css_node (child),
+                                 sibling ? gtk_widget_get_css_node (sibling) : NULL);
+    }
 }
 
 void