Allow swaynag to be disabled

sway/commands/swaynag_command.c

@@ -9,12 +9,17 @@ struct cmd_results *cmd_swaynag_command(int argc, char **argv) {
 		return error;
 	}
 
-	if (config->swaynag_command) {
-		free(config->swaynag_command);
+	free(config->swaynag_command);
+	config->swaynag_command = NULL;
+
+	char *new_command = join_args(argv, argc);
+	if (strcmp(new_command, "-") != 0) {
+		config->swaybg_command = new_command;
+		wlr_log(WLR_DEBUG, "Using custom swaynag command: %s",
+				config->swaynag_command);
+	} else {
+		free(new_command);
 	}
-	config->swaynag_command = join_args(argv, argc);
-	wlr_log(WLR_DEBUG, "Using custom swaynag command: %s",
-			config->swaynag_command);
 
 	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
 }

sway/config.c

@@ -137,6 +137,7 @@ void free_config(struct sway_config *config) {
 	free(config->floating_scroll_right_cmd);
 	free(config->font);
 	free(config->swaybg_command);
+	free(config->swaynag_command);
 	free((char *)config->current_config_path);
 	free((char *)config->current_config);
 	free(config);
@@ -167,7 +168,7 @@ static void set_color(float dest[static 4], uint32_t color) {
 }
 
 static void config_defaults(struct sway_config *config) {
-	config->swaynag_command = strdup("swaynag");
+	if (!(config->swaynag_command = strdup("swaynag"))) goto cleanup;
 	config->swaynag_config_errors = (struct swaynag_instance){
 		.args = "--type error "
 			"--message 'There are errors in your config file' "

sway/sway.5.scd

@@ -81,6 +81,9 @@ The following commands may only be used in the configuration file.
 	arguments. This should be placed at the top of the config for the best
 	results.
 
+	It can be disabled by setting the command to a single dash:
+	_swaynag\_command -_
+
 The following commands cannot be used directly in the configuration file.
 They are expected to be used with *bindsym* or at runtime through *swaymsg*(1).
 

sway/swaynag.c

@@ -11,6 +11,10 @@
 
 bool swaynag_spawn(const char *swaynag_command,
 		struct swaynag_instance *swaynag) {
+	if (!swaynag_command) {
+		return true;
+	}
+
 	if (swaynag->detailed) {
 		if (pipe(swaynag->fd) != 0) {
 			wlr_log(WLR_ERROR, "Failed to create pipe for swaynag");
@@ -58,6 +62,10 @@ void swaynag_kill(struct swaynag_instance *swaynag) {
 
 void swaynag_log(const char *swaynag_command, struct swaynag_instance *swaynag,
 		const char *fmt, ...) {
+	if (!swaynag_command) {
+		return;
+	}
+
 	if (!swaynag->detailed) {
 		wlr_log(WLR_ERROR, "Attempting to write to non-detailed swaynag inst");
 		return;