Comment 5 for bug 1511828

While we're in this part of the code, we could also reduce Perl warnings in the logs (currently: "Use of uninitialized value in string comparison (cmp) at ...") by swapping the order of the sort + grep:

grep { defined $row->{$_} } (
       sort {$row->{$a} <=> $row->{$b}} keys %$row
)

becomes:

sort { $row->{$a} <=> $row->{$b} } (
     grep { defined $row->{$_} } keys %$row
)