[gnome-text-editor] openpopover: fix warning about NULL widget

[Christian Hergert <chergert src gnome org>]

commit afba44cd9f236718c9c958e68de1a1cb2d7047f6
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jan 28 13:04:20 2022 -0800

    openpopover: fix warning about NULL widget

 src/editor-open-popover.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/src/editor-open-popover.c b/src/editor-open-popover.c
index 1b47fc5..b3103dd 100644
--- a/src/editor-open-popover.c
+++ b/src/editor-open-popover.c
@@ -207,7 +207,8 @@ on_search_entry_stop_search_cb (EditorOpenPopover *self,
     {
       EditorPage *page = editor_window_get_visible_page (window);
 
-      gtk_widget_child_focus (GTK_WIDGET (page), GTK_DIR_TAB_FORWARD);
+      if (page != NULL)
+        gtk_widget_child_focus (GTK_WIDGET (page), GTK_DIR_TAB_FORWARD);
     }
 }