Unit in Close Combat Dies before the phase, what happens?

What happens if you successfully charge a unit that subsequently dies before combat (as a result of the shooting phase)?  Do the charging units get to overrun? 

Here is the situation: My opponent flank charged my Sabretusk with his spear block.  Then in the shooting phase, he fells a nearby Giant who subsequently falls on the Sabretusk, smashing the poor cat into the ground.  No, what about the Spearmen block?  What happens to their charge/close-combat?  Null?  Auto-win?  I couldn't find this situation anywhere in the book, but I may have just missed it.  Common sense-wise, I would think that if a giant fell in front of you, it would stop your forward charge; rules wise, its unclear if they would overrun, as no combat is ever fought.

Nevermind, found it in the FAQ, he would have been able to overrun or reform before combat began.