904303 - Make compartment-checking "work" (that is, do same-runtime checks) on atoms and atom-valued jsids

Status: NEW

(Core :: JavaScript Engine, defect)

Description

[Jeff Walden [:Waldo]]

Apparently right now the only thing we do when compartment-checking a jsid, is check that it's right *if it's an object* (which no jsid ever is, in this enlightened post-E4X era).  We should also "compartment-check" atom-valued ids, by which we mean we should make sure they exist in the runtime (atoms being per-runtime, not per-compartment or per-zone or anything).

We'd want to change CompartmentChecker::check(jsid) to forward to CompartmentChecker::check(JSString*), then we'd want to change that do to a correct-runtime check on atoms (which currently go untested in that method), something like str->compartment()->runtimeFromAnyThread() == compartment->runtimeFromMainThread() in concert with a copy of the printf/MOZ_CRASH in CompartmentChecker::fail.  A fairly easy patch, someone with time just needs to do it.