Calling a function returned by another function directly causes wrong evaluation environment

```r
> f = fn() {
: a = 1
: fn() print(a)
: }
function() {
a <- 1
function() print(a)
}

> f()()
Error: object 'a' not found
backtrace:
1: f()() => None
2: print(a) => None
3: a => None
>
```

No files or tests are named. Start by running the provided f()() reproduction and trace how a function returned by another function receives its evaluation environment. Done means the nested print(a) resolves a without the object-not-found error.

Written by the indexing model from the issue text.