command, ack: add ack_quark()

src/ack.h

@@ -20,6 +20,8 @@
 #ifndef MPD_ACK_H
 #define MPD_ACK_H
 
+#include <glib.h>
+
 enum ack {
 	ACK_ERROR_NOT_LIST = 1,
 	ACK_ERROR_ARG = 2,
@@ -36,4 +38,14 @@ enum ack {
 	ACK_ERROR_EXIST = 56,
 };
 
+/**
+ * Quark for GError.domain; the code is an enum #ack.
+ */
+G_GNUC_CONST
+static inline GQuark
+ack_quark(void)
+{
+	return g_quark_from_static_string("ack");
+}
+
 #endif

src/command.c

@@ -183,6 +183,10 @@ print_error(struct client *client, GError *error)
 		enum playlist_result result = error->code;
 		g_error_free(error);
 		return print_playlist_result(client, result);
+	} else if (error->domain == ack_quark()) {
+		command_error(client, error->code, "%s", error->message);
+		g_error_free(error);
+		return COMMAND_RETURN_ERROR;
 	} else if (error->domain == db_quark()) {
 		switch ((enum db_error)error->code) {
 		case DB_DISABLED: