idle: client command "noidle" aborts idle

doc/COMMANDS

@@ -282,8 +282,10 @@ idle
 
 	While a client waits for "idle" results, the server disables
 	timeouts, allowing a client to wait for events as long as mpd
-	runs.  The "idle" command can be canceled by sending a new
-	command.
+	runs.  The "idle" command can be canceled by sending the
+	command "noidle" (no other commands are allowed).  MPD will
+	then leave "idle" mode and print results immediately; might be
+	empty at this time.
 
 
 COMMAND LIST

src/client.c

@@ -345,6 +345,27 @@ static int client_process_line(struct client *client, char *line)
 {
 	int ret = 1;
 
+	if (strcmp(line, "noidle") == 0) {
+		if (client->idle_waiting) {
+			/* send empty idle response and leave idle mode */
+			client->idle_waiting = false;
+			command_success(client);
+			client_write_output(client);
+		}
+
+		/* do nothing if the client wasn't idling: the client
+		   has already received the full idle response from
+		   client_idle_notify(), which he can now evaluate */
+
+		return 0;
+	} else if (client->idle_waiting) {
+		/* during idle mode, clients must not send anything
+		   except "noidle" */
+		ERROR("client %i: command \"%s\" during idle\n",
+		      client->num, line);
+		return COMMAND_RETURN_CLOSE;
+	}
+
 	if (client->cmd_list_OK >= 0) {
 		if (strcmp(line, CLIENT_LIST_MODE_END) == 0) {
 			DEBUG("client %i: process command "
@@ -418,9 +439,6 @@ static int client_input_received(struct client *client, int bytesRead)
 	char *newline, *next;
 	int ret;
 
-	/* any input from the client makes it leave "idle" mode */
-	client->idle_waiting = false;
-
 	client->bufferLength += bytesRead;
 
 	/* process all lines */