http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61131
--- Comment #5 from Mikael Pettersson <mikpelinux at gmail dot com> --- (In reply to Stephen Warren from comment #3) > Or is the definition of > undefined such that it propagates through the entire expression irrespective > of the expression's logic? It is. Once execution hits undefined behaviour all bets are off. "Undefined" is not some unspecified value you can choose to ignore.