The following is a simplified and related version of the issue I raised here:

```
function f!(x_work, x)
n = length(x);
for (j,k) in zip(1:n,n:-1:1)
x_work[j] = sin(x[k]);
end
x_work, x
end
function iterate_f!(x, x_work, n)
for j in 1:n
x, x_work = f!(x_work, x);
end
x, x_work
end
m = 5;
x = collect(range(0,stop=1,length=m));
x_work = zeros(m);
iterate_f!(x,x_work,1);
println(x);
println(x_work);
x = collect(range(0,stop=1,length=m));
x_work = zeros(m);
iterate_f!(x,x_work,2);
println(x);
println(x_work);
```

I am surprised that this appears to â€śfailâ€ť when the iteration is run with `n=1`

, but works when it is called with a larger value.