1197094 - ForOfIterator calls ToObject on iterable

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[André Bargull [:anba]]

Test case:
---
Object.defineProperty(Number.prototype, Symbol.iterator, {
  value() {
    "use strict";
    print("typeof", typeof this);
    return { next() { return {done: true}; } };
  }
});
new Map(0);
---


Expected: Prints "typeof number"
Actual: Prints "typeof object"

Comment 1

[Morgan Phillips [:mrrrgn]]

A nice gimme to end the week with.

Comment 2

[Morgan Phillips [:mrrrgn]]

Attachment: forofobj.diff

Comment 3

[Tom S. (please needinfo tschuster)]

Comment on attachment 8696100 [details] [diff] [review]
forofobj.diff

Review of attachment 8696100 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/vm/ForOfIterator.cpp
@@ +57,4 @@
>  
>      RootedValue callee(cx);
>      RootedId iteratorId(cx, SYMBOL_TO_JSID(cx->wellKnownSymbols().iterator));
>      if (!GetProperty(cx, iterableObj, iterableObj, iteratorId, &callee))

I wonder if we need to change this to iterable as well in the future.

Comment 4

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/ec1df10696ab

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/ec1df10696ab