fix bug in hLookAhead when byte encoding is in effect and hLookAhead is used twice on the last char in the stream.
fix bug in hLookAhead when byte encoding is in effect and hLookAhead is
used twice on the last char in the stream.

FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs