JSCLASS_NEW_RESOLVE_GETS_START specifies that resolve hooks be passed not just the object associated with the resolve hook, but the start object where the lookup started. But in the ECMAScript algorithms, only the resolve-hook object is passed along -- there's no way to get the start object. In order to implement the standard algorithms, then, I need to remove this flag. There's only one use in Gecko that must be addressed (see bug 758912). It's unknown whether any other embedders use it. I've posted to the newsgroup asking if anyone does; hopefully we can figure out workarounds for anyone who does: https://groups.google.com/forum/?fromgroups#!topic/mozilla.dev.tech.js-engine/da_9XU2XOD4
Note that this flag was added specifically for that Gecko use, by the way.
Created attachment 630388 [details] [diff] [review] Patch This depends on bug 758912 landing first, of course. The newsgroup post got no responses from anyone else using this, so it seems possible that Gecko was the only user (especially given what comment 1 says), and we need not worry about breaking any JSAPI clients.
The prereq just got completed, so landed: https://hg.mozilla.org/integration/mozilla-inbound/rev/026eb5f84c55 And a good thing, too, because the DOM accessor perf work needs a JSCLASS_* flag. :-D Excelsior!