Re: Object creation in SpiderMonkey 45

On Thursday, May 5, 2016 at 8:21:04 PM UTC+3, Boris Zbarsky wrote:
> On 5/5/16 12:50 PM, Mihai Dobrescu wrote:
> > On Thursday, May 5, 2016 at 7:38:32 PM UTC+3, Mihai Dobrescu wrote:
> >> On Thursday, May 5, 2016 at 7:27:05 PM UTC+3, Boris Zbarsky wrote:
> >>> Things used to default to "if you pass no prototype and just the class
> >>> we'll do some fragile lookup to try to figure out the right prototype",
> >>> but that went away in https://bugzilla.mozilla.org/show_bug.cgi?id=1125567
> >>>
> >>> So you need to pass in the right prototype object here.
> >>>
> >>> -Boris
> >>
> >> I don't understand what you mean. It is 45, not 38.
> >
> > + I used to pass nullptr for prototype, in 38, and it worked.
> 
> Sure.  It worked because JS_NewObject saw you passed null for the proto 
> but a non-default class, took the class name, looked it up as a property 
> on the global, assumed the result was the constructor for your class, 
> got its .prototype and used that as the prototype.
> 
> That whole "look up the name on the global and hope it has something to 
> do with us" thing was removed in the bug I link to above, which was 
> fixed in Firefox 40.  Notably, 38 < 40 <= 45.
> 
> > I would expect that after initialization of classes, all the stuff to work as their definitions are loaded, including their functions.
> 
> The definitions are "loaded".  The functions are defined on the 
> prototype object for your class.  But the object you're creating doesn't 
> have that on its proto chain, because of the behavior change above.
> 
> -Boris

My mind just blown up. What is the status now in 45? Is it a bug, or should I do things differently? If so, how?