adapt buffered_socket_test to the corrected return values of buffured_socket_read functions
adapt buffered_socket_test to the corrected return values of buffured_socket_read functions

mloy/cjet,mloy/cjet,gatzka/cjet,gatzka/cjet,gatzka/cjet,mloy/cjet,mloy/cjet,gatzka/cjet,mloy/cjet,gatzka/cjet