What is the ruling when a partner delegates his partner to manumit his share of a slave, and the agent states, 'My share is free'?

Primary text

If the agent states, 'My share is free,' then the agent's share is manumitted, and this extends by extension (*sarayah*) to the partner's share, and the patronage (*wala'*) accrues to the agent. If the agent manumits the share of the principal, that share is manumitted, and this extends by extension to the principal's share, and the patronage accrues to the principal.