[gnome-text-editor] prefs: track if the window has been disposed

[Christian Hergert <chergert src gnome org>]

commit f7f0cf17caa8111a585ad2ab236cc59adb4c2694
Author: Christian Hergert <chergert redhat com>
Date:   Wed Feb 2 12:30:51 2022 -0800

    prefs: track if the window has been disposed

 src/editor-preferences-dialog.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/src/editor-preferences-dialog.c b/src/editor-preferences-dialog.c
index 5bcc6bd..cde5762 100644
--- a/src/editor-preferences-dialog.c
+++ b/src/editor-preferences-dialog.c
@@ -46,6 +46,8 @@ struct _EditorPreferencesDialog
   GtkFlowBox           *scheme_group;
   GtkSourceBuffer      *buffer;
   GtkSourceView        *source_view;
+
+  guint                 disposed : 1;
 };
 
 G_DEFINE_TYPE (EditorPreferencesDialog, editor_preferences_dialog, ADW_TYPE_PREFERENCES_WINDOW)
@@ -395,6 +397,8 @@ editor_preferences_dialog_dispose (GObject *object)
 {
   EditorPreferencesDialog *self = (EditorPreferencesDialog *)object;
 
+  self->disposed = TRUE;
+
   g_clear_object (&self->settings);
   g_clear_object (&self->css_provider);