This form is usual. It will be often found after "até", "para" and others. (In this case it can be exchanged by the present subjunctive if you add a "que": até que ele volte)
But it's conjugated in a form called "personal infinitive" (infinitivo pessoal).
Até eu chegar
Até tu chegares
Até ele chegar
Até nós chegarmos
Até vós chegardes
Até eles chegarem
yes I put that too. Wait until he returns. All hearts gone now, it's back to the beginning again.