1. add_interdomain and add_secure are optional... not all maps use these
keys. if we are unable to add them due to a YPERR_KEY (meaning they
are not being used), then we should not flag this as a general error.
2. if we have a failure (status <= 0) we unlink_db() the temp database
as part of error handling. but we should not overwrite our error
status code with the return value from unlink_db() because if the
unlink_db() works (likely true) than that success will wipe out our
error code and the calling yppush will think we worked.
a8036503d8