rcl_get_localhost_only function not returning a rmw_localhost_only_t value

[Blast545]

While adding tests for the rcl package I realized the localhost.c function rcl_get_localhost_only uses this logic to return the possible value of the localhost_only variable:

rcl/rcl/src/rcl/localhost.c

Line 44 in e47042c

*localhost_only = ros_local_host_env_val != NULL && strcmp(ros_local_host_env_val, "1") == 0;

Which only returns 0 or 1, but the current possible values for this variable are 0-1-2, as implemented in rmw/localhost.h:

typedef enum RMW_PUBLIC_TYPE rmw_localhost_only_t
{
  /// Uses ROS_LOCALHOST_ONLY environment variable.
  RMW_LOCALHOST_ONLY_DEFAULT = 0,
  /// Forces using only localhost.
  RMW_LOCALHOST_ONLY_ENABLED = 1,
  /// Forces disabling localhost only.
  RMW_LOCALHOST_ONLY_DISABLED = 2,
} rmw_localhost_only_t;

[Blast545]

After checking the expected usage of this function, it is expected that the result of this function to be a boolean value because the result coming from this is then fed to rmw_create_node() that takes localhost_only value as a boolean.

I think the solution to this would be changing the rcl_get_localhost_only signature to return boolean instead.

[Blast545]

Closed with #670