Properly finalizing a GTK4 file filter

(Using GTK 4.8 on Debian)

I created a file filter for specific image suffixes:

GtkFileFilter *file_filter = gtk_file_filter_new ();
gtk_file_filter_add_suffix (file_filter, "png");
gtk_file_filter_add_suffix (file_filter, "jpg");
gtk_file_filter_add_suffix (file_filter, "gif");

I then associated the file filter with a file chooser.

gtk_file_chooser_set_filter (GTK_FILE_CHOOSER(file_chooser), file_filter );

How do I properly finalize the file filter?

• Does it have a reference count incremented by the file chooser, so destroying the file chooser also destroys the file filter?
• Do I need to explicitly decrement the reference count using g_object_unref(file_filter)?
• Something else?

I ask because the second option, g_object_unref(file_filter), gives me a runtime error g_object_unref: assertion 'G_IS_OBJECT (object)' failed.

This can be done like this --

  //1.Default filter (all files) 
  GtkFileFilter *filter = gtk_file_filter_new ();
  gtk_file_filter_set_name (filter, "All Files");
  gtk_file_filter_add_pattern (filter, "*");
  gtk_file_chooser_add_filter (GTK_FILE_CHOOSER (dialog), filter);

  // Make this filter the default 
  gtk_file_chooser_set_filter (GTK_FILE_CHOOSER (dialog), filter);
  g_object_unref (filter);

  //2.filter start with D**
  filter = gtk_file_filter_new ();
  gtk_file_filter_set_name (filter, "Starts with D");
  gtk_file_filter_add_pattern (filter, "D*");
  gtk_file_chooser_add_filter (GTK_FILE_CHOOSER (dialog), filter);
  g_object_unref (filter);

  //3.filter jpeg & png
  filter = gtk_file_filter_new ();
  gtk_file_filter_set_name (filter, "PNG and JPEG");
  gtk_file_filter_add_mime_type (filter, "image/jpeg");
  gtk_file_filter_add_mime_type (filter, "image/png");
  gtk_file_chooser_add_filter (GTK_FILE_CHOOSER (dialog), filter);
  g_object_unref (filter);

NOTE: According to the current Gtk4 documentation; GtkFileChooser - Deprecated since: 4.10,,Use GtkFileDialog.