It's weird because it has side-effects (namely, implicitly adding/setting a named property in the current scope object, if any). It means that a top-level scri

It's weird because it has side-effects (namely, implicitly adding/setting a named property in the current scope object, if any). It means that a top-level script using `var` that is subsequently refactored into a scoped function somewhere will now have different semantics and might break if other code depended on `var` creating a new global property.