gio: call g_file_enumerator_close in dispose

`g_file_enumerator_finalize` should not call `g_file_enumerator_close`
because object parts (i.e. subclass variable and/or resources) might
already be freed, causing memory safety issues.
A better place to call `g_file_enumerator_close` is
`g_file_enumerator_dispose` because it is safe to access the object
memory here.

Fixes #3713

Signed-off-by: fbrouille <150549-fbrouille@users.noreply.gitlab.gnome.org>

gio/gfileenumerator.c

@@ -127,20 +127,10 @@ g_file_enumerator_dispose (GObject *object)
     enumerator->priv->container = NULL;
   }
 
-  G_OBJECT_CLASS (g_file_enumerator_parent_class)->dispose (object);
-}
-
-static void
-g_file_enumerator_finalize (GObject *object)
-{
-  GFileEnumerator *enumerator;
-
-  enumerator = G_FILE_ENUMERATOR (object);
-  
   if (!enumerator->priv->closed)
     g_file_enumerator_close (enumerator, NULL, NULL);
 
-  G_OBJECT_CLASS (g_file_enumerator_parent_class)->finalize (object);
+  G_OBJECT_CLASS (g_file_enumerator_parent_class)->dispose (object);
 }
 
 static void
@@ -150,7 +140,6 @@ g_file_enumerator_class_init (GFileEnumeratorClass *klass)
 
   gobject_class->set_property = g_file_enumerator_set_property;
   gobject_class->dispose = g_file_enumerator_dispose;
-  gobject_class->finalize = g_file_enumerator_finalize;
 
   klass->next_files_async = g_file_enumerator_real_next_files_async;
   klass->next_files_finish = g_file_enumerator_real_next_files_finish;

gio/tests/file-enumerator.c

@@ -0,0 +1,103 @@
+/* GLib testing framework examples and tests
+ *
+ * Copyright 2025 GNOME Foundation, Inc.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <gio/gio.h>
+
+#define TYPE_TEST_FILE_ENUMERATOR (test_file_enumerator_get_type ())
+#define TEST_FILE_ENUMERATOR(o) (G_TYPE_CHECK_INSTANCE_CAST ((o), TYPE_TEST_FILE_ENUMERATOR, TestFileEnumerator))
+#define IS_TEST_FILE_ENUMERATOR(o) (G_TYPE_CHECK_INSTANCE_TYPE ((o), TYPE_TEST_FILE_ENUMERATOR))
+
+typedef struct
+{
+  GFileEnumerator parent_instance;
+  unsigned int n_times_closed; // Number of times the enumerator has been closed
+} TestFileEnumerator;
+
+typedef struct
+{
+  GFileEnumeratorClass parent_class;
+} TestFileEnumeratorClass;
+
+GType test_file_enumerator_get_type (void) G_GNUC_CONST;
+
+G_DEFINE_TYPE (TestFileEnumerator, test_file_enumerator, G_TYPE_FILE_ENUMERATOR)
+
+static gboolean
+test_file_enumerator_close (GFileEnumerator *enumerator,
+                            GCancellable *cancellable,
+                            GError **error)
+{
+  TestFileEnumerator *test = TEST_FILE_ENUMERATOR (enumerator);
+  ++test->n_times_closed;
+  return TRUE;
+}
+
+static void
+test_file_enumerator_init (TestFileEnumerator *enumerator)
+{
+  enumerator->n_times_closed = 0;
+}
+
+static void
+test_file_enumerator_class_init (TestFileEnumeratorClass *klass)
+{
+  GFileEnumeratorClass *enumerator_class;
+
+  enumerator_class = G_FILE_ENUMERATOR_CLASS (klass);
+  enumerator_class->close_fn = test_file_enumerator_close;
+}
+
+static void
+test_close_on_dispose (void)
+{
+  GFile *dir;
+  TestFileEnumerator *enumerator;
+
+  dir = g_file_new_for_path (g_get_tmp_dir ());
+
+  enumerator = g_object_new (TYPE_TEST_FILE_ENUMERATOR,
+                             "container", dir,
+                             NULL);
+
+  // Check enumerator is not closed initially
+  g_assert_cmpuint (enumerator->n_times_closed, ==, 0);
+
+  g_object_run_dispose (G_OBJECT (enumerator));
+
+  // Check enumerator is closed after 1st dispose
+  g_assert_cmpuint (enumerator->n_times_closed, ==, 1);
+
+  g_object_run_dispose (G_OBJECT (enumerator));
+
+  // Check enumerator is not closed twice after 2nd dispose
+  g_assert_cmpuint (enumerator->n_times_closed, ==, 1);
+
+  g_object_unref (enumerator);
+  g_object_unref (dir);
+}
+
+int
+main (int argc, char *argv[])
+{
+  g_test_init (&argc, &argv, NULL);
+
+  g_test_add_func ("/file-enumerator/close-on-dispose", test_close_on_dispose);
+  return g_test_run ();
+}

gio/tests/meson.build

@@ -98,6 +98,7 @@ gio_tests = {
     # FIXME: https://gitlab.gnome.org/GNOME/glib/-/issues/3148
     'can_fail' : host_system in ['darwin', 'windows', 'gnu'],
   },
+  'file-enumerator' : {},
   'inet-address' : {},
   'io-stream' : {},
   'max-version' : {'install' : false},