desc: Regression tests for issue #546, variable shadowing
tests:

    # Just a single nesting level, for sanity
    - js: r(1).do(function(a) { return a; })
      py: r.expr(1).do(lambda a:a)
      ot: 1

    # Nested but returning the inner var
    - js: |-
        r(1).do(function(a) {
          return r(2).do(function(b) {
            return b;
          });
        })
      py: r.expr(1).do(lambda a:r.expr(2).do(lambda b:b))
      ot: 2

    # Nested but returning the outer var (this was the problem in 546)
    - js: |-
        r(1).do(function(a) {
          return r(2).do(function(b) {
            return a;
          });
        })
      py: r.expr(1).do(lambda a:r.expr(2).do(lambda b:a))
      ot: 1