mangosR2/mangos — comment on commit 033d6ddd9d36fbb31afc0f1c32056ef906b00dc1
File: src/game/Creature.cpp line 2134
By Iriskin:

Yes it's needed as it's a part of `for` statement, though all three expressions are required. For example, `for(;;) { ... }` is equivalent to `while(1) { ... }`.