prefs: avoid deprecated 'g_settings_list_keys'

src/core/prefs.c

@@ -1683,10 +1683,14 @@ static MetaKeyPref key_bindings[] = {
 static void
 init_bindings (GSettings *settings)
 {
+  GSettingsSchema *schema;
   gchar **list = NULL;
   gchar *str_val = NULL;
 
-  list = g_settings_list_keys (settings);
+  g_object_get (settings, "settings-schema", &schema, NULL);
+  list = g_settings_schema_list_keys (schema);
+  g_settings_schema_unref (schema);
+
   while (*list != NULL)
     {
       str_val = g_settings_get_string (settings, *list);
@@ -1712,10 +1716,14 @@ init_window_bindings (void)
 static void
 init_commands (void)
 {
+  GSettingsSchema *schema;
   gchar **list = NULL;
   gchar *str_val = NULL;
 
-  list = g_settings_list_keys (settings_command);
+  g_object_get (settings_command, "settings-schema", &schema, NULL);
+  list = g_settings_schema_list_keys (schema);
+  g_settings_schema_unref (schema);
+
   while (*list != NULL)
     {
       str_val = g_settings_get_string (settings_command, *list);
@@ -1729,10 +1737,14 @@ init_commands (void)
 static void
 init_workspace_names (void)
 {
+  GSettingsSchema *schema;
   gchar **list = NULL;
   gchar *str_val = NULL;
 
-  list = g_settings_list_keys (settings_workspace_names);
+  g_object_get (settings_workspace_names, "settings-schema", &schema, NULL);
+  list = g_settings_schema_list_keys (schema);
+  g_settings_schema_unref (schema);
+
   while (*list != NULL)
     {
       str_val = g_settings_get_string (settings_workspace_names, *list);