fixes mtest to pick up the correct 'B'; add many test cases/references; revert part of ab604aa4d75e9776dd3519149000d5c89291bfdc that claims to have fixed something (it did not fix)

fixes mtest to pick up the correct 'B'; add many test cases/references; revert part of ab604aa4d75e9776dd3519149000d5c89291bfdc that claims to have fixed something (it did not fix) #438