5 digit port numbers are truncated

[jimmy-mcelwain]

Context Yaskawa-Global/motoros2#376

Describe the bug
If a 5 digit port number is specified, the last digit gets cut off.

To Reproduce
Specify a 5 digit port number. If I choose 16510, then the "real" port number ends up being 1651.

Expected behaviour
If I specify a 5 digit port number, the last digit should not be truncated. It should alarm for 0 or 6+ digits.

System information (please complete the following information):

• Found on a YRC1000. Client PC is running micro-ros agent.
• Found on ROS2 Jazzy
• 5.01

Additional context

The problem lies here:

rmw_microxrcedds/rmw_microxrcedds_c/src/rmw_microros/init_options.c

Lines 100 to 105 in 554445f

	if (port != NULL && strlen(port) <= MAX_PORT_LEN) {
	snprintf(rmw_options->impl->transport_params.agent_port, MAX_PORT_LEN, "%s", port);
	} else {
	RMW_UROS_TRACE_MESSAGE("default port configuration error")
	return RMW_RET_INVALID_ARGUMENT;
	}

With the maximum length argument in snprintf being MAX_PORT_LENGTH, that means that at most MAX_PORT_LENGTH - 1 characters will be copied into the agent_port array, since it needs room to put the terminating \0.

[pablogs9]

Good catch, thanks.

#315

[pablogs9]

Closing as #315 merged