If Trent truly taught Baptism of desire, it would have listed it as an instrumental cause of justification later on in Session 6. It didn't do this, because the Holy Ghost protects an ecuмenical council from teaching error, not theologians. When all of Session 6 is read in context, without cherry-picking and twisting chap. 4, it's obvious that Trent taught a man cannot be justified without the laver of regeneration.
Pope Paul III, Council of Trent, Sess. 6, Chap. 7, the Causes of Justification: “The causes of this Justification are: the final cause is the glory of God and of Christ… the efficient cause is truly a merciful God… the meritorious cause is His most beloved and only-begotten Son… the instrumental cause is the sacrament of baptism, which is the sacrament of faith, without faith no one is ever justified… This faith, in accordance with apostolic tradition, catechumens beg of the Church before the sacrament of baptism, when they ask for faith which bestows life eternal…”
Why do catechumens beg for Faith in the sacramental rite, if they already have it through "BOD"? Its illogical.
According to Trent’s decree, catechumens, i.e. people who desire baptism, do not have the faith that bestows life eternal until they are baptized. Only then do they become members of the faithful, as the Church has always taught.
This video covers the issue comprehensively: