[gnome-text-editor] savechangesdialog: avoid (null) in title text

[Christian Hergert <chergert src gnome org>]

commit 32ac98f14ac87eda05c384733b58293923bd5c3b
Author: Christian Hergert <chergert redhat com>
Date:   Mon Jul 26 16:35:41 2021 -0700

    savechangesdialog: avoid (null) in title text
    
    Fixes #124

 src/editor-save-changes-dialog.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/src/editor-save-changes-dialog.c b/src/editor-save-changes-dialog.c
index 93debd8..8cfeb72 100644
--- a/src/editor-save-changes-dialog.c
+++ b/src/editor-save-changes-dialog.c
@@ -279,6 +279,9 @@ _editor_save_changes_dialog_new (GtkWindow *parent,
         {
           g_autofree gchar *tmp = g_steal_pointer (&title_str);
 
+          if (tmp == NULL)
+            tmp = g_strdup (_("Untitled Document"));
+
           /* translators: %s is replaced with the title of the file */
           title_str = g_strdup_printf (_("%s (new)"), tmp);