Bug in Boost's matrix_expression.hpp?

As of version 1.64.0 of Boost, the file boost\numeric\ublas\matrix_expression.hpp seems to be with a potential bug (around line 2224):

if (it2_ != it2_end_)
    if (it2_.index1 () <= i_)
        ++ it2_;
    if (it2_ != it2_end_) {
        index2 = it2_.index1 ();
}

Notice the lack of the opening curly braces in the topmost if. Judging by identation, it is a bug. If so, sorry, but I'm not willing to get 1000's of messages in my already busy inbox by registering to their mailing list just to report a small bug. So, I hope this message finds its way to an active Boost community member. Is it really buggy, then?