We will want to disable globally installed add-ons in the web app runtime on desktop. I'm told this is simply a flag so hopefully it's easy to pull off.
Note for testing - Need a list of top installed global add-ons when verifying the fix for this.
Created attachment 622838 [details] [diff] [review]
This turns out to be pretty easy.
Justin - Do you have a listing of top add-ons that are typically installed globally? I would like to try a couple of those to verify this bug.
A list of most-commonly-installed add-ons wouldn't be useful, because in order for an add-on to work in web apps it would need to explicitly target the web app runtime (whose app ID is different than Firefox's). I wrote a simple add-on that does so: https://people.mozilla.com/~gavin/alerter.xpi (it just shows an alert on startup). See https://developer.mozilla.org/en/Installing_extensions for information about how to "globally install" it.