What is the ruling on the indenture contract if the Harbī master contracts it in Dar al-Harb, and the slave flees and enters Muslim territory?

Primary text

If the contract was made in Dar al-Harb and the slave flees into Muslim territory, the indenture contract is voided because his ownership was removed by his own subjugation of himself, similar to if he subjugated any other of his master's property. This is the case whether he enters as a Muslim or not. If he enters with his master's permission, the indenture remains valid because he did not subjugate his master.