config: don't set default plugins in nm-config keyfile

Like all other keys that can have a default value, substitute the
default only when needed. In this way, we can tell later if the
value comes from configuration file or if it's the default value.

Also, rename CONFIG_PLUGINS_DEFAULT to NM_CONFIG_PLUGINS_DEFAULT.

configure.ac

@@ -134,7 +134,7 @@ test "$enable_ifupdown" = "yes"           && distro_plugins="$distro_plugins,ifu
 test "$enable_ifnet" = "yes"              && distro_plugins="$distro_plugins,ifnet"
 distro_plugins="${distro_plugins#,}"
 
-AC_DEFINE_UNQUOTED(CONFIG_PLUGINS_DEFAULT, "$config_plugins_default", [Default configuration option for main.plugins setting])
+AC_DEFINE_UNQUOTED(NM_CONFIG_PLUGINS_DEFAULT, "$config_plugins_default", [Default configuration option for main.plugins setting])
 if test "${enable_config_plugin_ibft}" = yes; then
 	AC_DEFINE(WITH_SETTINGS_PLUGIN_IBFT, 1, [Whether compilation of ibft setting plugin is enabled])
 else

src/nm-config.c

@@ -512,7 +512,7 @@ nm_config_cmd_line_options_add_to_entries (NMConfigCmdLineOptions *cli,
 			{ "intern-config", 0, 0, G_OPTION_ARG_FILENAME, &cli->intern_config_file, N_("Internal config file location"), N_(DEFAULT_INTERN_CONFIG_FILE) },
 			{ "state-file", 0, 0, G_OPTION_ARG_FILENAME, &cli->state_file, N_("State file location"), N_(DEFAULT_STATE_FILE) },
 			{ "no-auto-default", 0, G_OPTION_FLAG_HIDDEN, G_OPTION_ARG_FILENAME, &cli->no_auto_default_file, N_("State file for no-auto-default devices"), N_(DEFAULT_NO_AUTO_DEFAULT_FILE) },
-			{ "plugins", 0, 0, G_OPTION_ARG_STRING, &cli->plugins, N_("List of plugins separated by ','"), N_(CONFIG_PLUGINS_DEFAULT) },
+			{ "plugins", 0, 0, G_OPTION_ARG_STRING, &cli->plugins, N_("List of plugins separated by ','"), N_(NM_CONFIG_PLUGINS_DEFAULT) },
 			{ "configure-and-quit", 0, 0, G_OPTION_ARG_NONE, &cli->configure_and_quit, N_("Quit after initial configuration"), NULL },
 			{ "debug", 'd', 0, G_OPTION_ARG_NONE, &cli->is_debug, N_("Don't become a daemon, and log to stderr"), NULL },
 
@@ -947,7 +947,6 @@ read_entire_config (const NMConfigCmdLineOptions *cli,
 	guint i;
 	gs_free char *o_config_main_file = NULL;
 	GString *str;
-	char **plugins_default;
 
 	g_return_val_if_fail (config_dir, NULL);
 	g_return_val_if_fail (system_config_dir, NULL);
@@ -958,11 +957,6 @@ read_entire_config (const NMConfigCmdLineOptions *cli,
 	/* create a default configuration file. */
 	keyfile = nm_config_create_keyfile ();
 
-	plugins_default = g_strsplit (CONFIG_PLUGINS_DEFAULT, ",", -1);
-	if (plugins_default && plugins_default[0])
-		nm_config_keyfile_set_string_list (keyfile, NM_CONFIG_KEYFILE_GROUP_MAIN, "plugins", (const char *const*) plugins_default, -1);
-	g_strfreev (plugins_default);
-
 	system_confs = _get_config_dir_files (system_config_dir);
 	confs = _get_config_dir_files (config_dir);
 
@@ -2305,8 +2299,6 @@ init_sync (GInitable *initable, GCancellable *cancellable, GError **error)
 
 	priv->plugins = _nm_utils_strv_cleanup (g_key_file_get_string_list (keyfile, NM_CONFIG_KEYFILE_GROUP_MAIN, "plugins", NULL, NULL),
 	                                        TRUE, TRUE, TRUE);
-	if (!priv->plugins)
-		priv->plugins = g_new0 (char *, 1);
 
 	priv->monitor_connection_files = nm_config_keyfile_get_boolean (keyfile, NM_CONFIG_KEYFILE_GROUP_MAIN, "monitor-connection-files", FALSE);
 

src/settings/nm-settings.c

@@ -2292,11 +2292,19 @@ nm_settings_start (NMSettings *self, GError **error)
 	GDBusProxy *proxy;
 	GVariant *variant;
 	GError *local_error = NULL;
+	const char **plugins;
+	gs_strfreev char **plugins_default = NULL;
 
 	priv = NM_SETTINGS_GET_PRIVATE (self);
 
 	/* Load the plugins; fail if a plugin is not found. */
-	if (!load_plugins (self, nm_config_get_plugins (priv->config), error)) {
+	plugins = nm_config_get_plugins (priv->config);
+	if (!plugins) {
+		plugins_default = g_strsplit (NM_CONFIG_PLUGINS_DEFAULT, ",", -1);
+		plugins = (const char **) plugins_default;
+	}
+
+	if (!load_plugins (self, plugins, error)) {
 		g_object_unref (self);
 		return FALSE;
 	}