Weird breaking change in Stata 16 with views, cross() and column indexing

[Wilbur Townsend]

My package `elasticregress` has stopped working in Stata 16. I think the below code illustrates what has broken/changed:

// Create ten observations with a weight variable
clear
set obs 10
generate weight = 1

mata:
// In Mata, create an x vector and load the weights into a view.
x = J(10,1,1)
w = J(10,1,1)
st_view(w, ., "weight")     
// The next two displays should be equivalent, but they are not. The first
// returns 10 while the second returns a missing value.
x_new = x[,1]
display(strofreal(cross(x_new, w, x_new)))
display(strofreal(cross(x[,1], w, x[,1])))
end

Note that the problem has something to do with the weights being loaded into a view. When I delete the st_view line, there is no problem.

[Jeff Pitblado (StataCorp)]

Thanks to Wilbur's reproducible example, we will have this fixed very soon.