I found a major bug in the shim code while working on bug 1059007. When you create a new Interposition, you're allowed to pass in an existing one that it inherits from. We use the proto chain to link them together. However, when looking for shims for a particular property, we use interp.hasOwnProperty, which doesn't actually look at the prototype. The reason I switched to hasOwnPrototype is because I didn't want stuff from Object.prototype showing up as a shim. However, we can just set the prototype of the base shims to null to avoid that. I also added a name property to every shim, which helps debugging. And I fixed a variable that needed |let| in front of it. It's pretty clear that we need tests for this code though. I'll get working on that and post in this bug when I'm done.

Comment on attachment 8480845 [details] [diff] [review] fix-shims Review of attachment 8480845 [details] [diff] [review]: ----------------------------------------------------------------- This makes sense, but yes please for tests. ::: toolkit/components/addoncompat/RemoteAddonsParent.jsm @@ +457,5 @@ > }, > > dispatch: function(browser, type, isTrusted, event) { > let targets = this.getTargets(browser); > + for (let target of targets) { Ouch - good catch.

Moving old M2 P1 bugs to M3.