1313034 - ImmutableBinding of "ES-6" not work in loop "for-in"

Status: RESOLVED DUPLICATE of bug 449811

(Core :: JavaScript Engine, defect)

Description

[Ivan]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:49.0) Gecko/20100101 Firefox/49.0
Build ID: 20161019084923

Steps to reproduce:

Im run code:

let o = { a:1, s:2, d:3, f:4, g:5, h:6};

for(let i in o){
  setTimeout(function(){
    alert(i)
  }, 0);
}




Actual results:

That code always alerting 'h' symbol.


Expected results:

Should be alerting sequence of all keys ('a', 's', 'd', 'f', 'g', 'h')

Comment 1

[Tooru Fujisawa [:arai]]

dupe of bug 449811 and it's fixed in bug 1263355 (firefox 51).