379528 - Changing __proto__ causes uneval to throw with e.g. "RegExp.prototype.toSource called on incompatible global"

Status: RESOLVED WORKSFORME

(Core :: JavaScript Engine, defect)

Description

[Jesse Ruderman]

js> this.__proto__ = /r/
/r/
js> uneval(this)
typein:2: TypeError: RegExp.prototype.toSource called on incompatible global

Comment 1

[Jesse Ruderman]

js> this.__proto__ = <x/>

js> uneval(this)
typein:2: TypeError: XML.prototype.toString called on incompatible global

Comment 2

[Igor Bukanov]

(In reply to comment #0)
> js> this.__proto__ = /r/
> /r/
> js> uneval(this)
> typein:2: TypeError: RegExp.prototype.toSource called on incompatible global

This is not a bug since RegExp.prototype.toSource is not generic and requires this to be regex.

(In reply to comment #1)
> js> this.__proto__ = <x/>
> 
> js> uneval(this)
> typein:2: TypeError: XML.prototype.toString called on incompatible global

The bug here is why XML.prototype.toString and not XML.prototype.toSource is reported. 

Comment 3

[Ryan VanderMeulen [:RyanVM]]

js> this.__proto__ = <x/>
typein:3: TypeError: can't set prototype of an object to an XML value

WFM?

Comment 4

[Jeff Walden [:Waldo]]

Sure, I think we can say that.