Extension broken on FF 38: "Error: Permission denied to access property "valueOf"

[lkuper]

Reported by Chris Whealy regarding his demo:

I’ve just updated Firefox to version 38.0.5 and installed the latest River Trail Extension, but now I’m getting an error from River Trail about 64 bit floating point not being enabled.

Is this due to the extension not working in FF38, or is there a configuration setting I need to modify?

The floating-point message is a red herring, there is something else wrong here.

[lkuper]

So here's what I'm seeing:

Starting in FF 38, running any of our demos results in this error in the browser console:

Error: Permission denied to access property "valueOf" RiverTrail.js:5142:12

Right before that, we see:

XrayWrapper denied access to property toSource (reason: object is not safely Xrayable). See https://developer.mozilla.org/en-US/docs/Xray_vision for more information. Note that only the first denied property access from a given global object will be reported. RiverTrailInterface.js:319:0

In the extension debugger, we get a type error expected type pointer, got ({}) at line 324 of RiverTrailInterface.js.

Will play around some more in the debugger and see what I can do.

[lkuper]

The issue has something to do with the mapData function in the extension that allocates a buffer on the OpenCL side and returns a pointer to it. It might have something to do with __exposedProps__. That's just a suspicion.