(function f() {
    var a,b;
    with(a = { set x(v) { print("fail") } }) {
        with(b = { get x() { delete this.x; return 0 } }) {
            x-=1;
        }
    }

    return b.x
})()

should not print "fail"

Other variants:

jjs> (function(global){"use strict";
Object.defineProperty(global,"x",{get: function(){delete global.x;
return 0}, configurable:true}); x-=1 })(this)

Expected: global "x" is -1
Actual: ReferenceError


jjs> (function(global){"use strict";
Object.defineProperty(global,"x",{get: function(){delete global.x;
return 0}, configurable:true}); x-- })(this)

Expected: global "x" is -1
Actual: ReferenceError