1054998 - Closures created by expressions in the formal parameter list should not have visibility of declarations in the function body

Status: RESOLVED DUPLICATE of bug 1022967

(Core :: JavaScript Engine, defect)

Description

[Amjad Masad]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.143 Safari/537.36

Steps to reproduce:

Open firefox console and evaluate:

function foo(bar=function(){ console.log(x) }){
  var x = 1;
  bar();
}
foo();



Actual results:

logs "1" to the console


Expected results:

A ReferenceError should've been thrown because x is only defined inside the function declaration body and the closure created in the default parameter expression shouldn't have access to the function's scope.