pipewire: allow NULL pointers in pw_free_strv()

Just like the real free() we should just ignore a NULL pointer, makes the
caller code easier for those instances where properties are optional.

src/modules/module-protocol-pulse/modules/module-combine-sink.c

@@ -384,7 +384,6 @@ static int module_combine_sink_unload(struct client *client, struct module *modu
 		pw_manager_destroy(d->manager);
 	if (d->core != NULL)
 		pw_core_disconnect(d->core);
-	if (d->sink_names)
 	pw_free_strv(d->sink_names);
 	free(d->sink_name);
 
@@ -462,7 +461,6 @@ struct module *create_module_combine_sink(struct impl *impl, const char *argumen
 	return module;
 out:
 	pw_properties_free(props);
-	if (sink_names)
 	pw_free_strv(sink_names);
 	errno = -res;
 

src/modules/spa/module-device.c

@@ -117,7 +117,6 @@ error_arguments:
 	pw_log_error("usage: module-spa-device " MODULE_USAGE);
 	goto error_exit_cleanup;
 error_exit_cleanup:
-	if (argv)
 	pw_free_strv(argv);
 	return res;
 }

src/modules/spa/module-node.c

@@ -119,7 +119,6 @@ error_arguments:
 	pw_log_error("usage: module-spa-node " MODULE_USAGE);
 	goto error_exit_cleanup;
 error_exit_cleanup:
-	if (argv)
 	pw_free_strv(argv);
 	return res;
 }

src/pipewire/pipewire.c

@@ -221,7 +221,6 @@ static void configure_debug(struct support *support, const char *str)
 	if (n_tokens > 1)
 		support->categories = pw_split_strv(level[1], ",", INT_MAX, &n_tokens);
 
-	if (level)
 	pw_free_strv(level);
 }
 
@@ -564,7 +563,6 @@ void pw_deinit(void)
 			unref_handle(h);
 		unref_plugin(p);
 	}
-	if (support->categories)
 	pw_free_strv(support->categories);
 	free(support->i18n_domain);
 	spa_zero(global_support);

src/pipewire/utils.c

@@ -99,6 +99,10 @@ SPA_EXPORT
 void pw_free_strv(char **str)
 {
 	int i;
+
+	if (str == NULL)
+		return;
+
 	for (i = 0; str[i]; i++)
 		free(str[i]);
 	free(str);