The patch in bug 878605 has this: >+bool >+Proxy::invoke(JSContext *cx, HandleObject proxy, HandleObject receiver, HandleId id, >+ MutableHandleValue vp) >+{ >+ if (!IsScriptedDirectProxy(proxy)) >+ return Proxy::get(cx, proxy, receiver, id, vp); This bug is to * remove those two lines, so the invoke trap is enabled for all proxies * add implementations for our existing proxy handlers, and in particular: * for legacy ("indirect") scripted proxies, continue calling .get() * for cross-compartment wrappers, maintain the existing behavior but make method calls faster Also we need to change the order of operations so that CALLPROP/CALLELEM happen after the arguments are evaluated. Not sure if that fits in the same bug with the rest.

Support for the invoke trap was removed from ES6. Bug 878605 was WONTFIXed.