Andreas Tolfsen ❲:ato❳ Reporter
	Description • 9 years ago

When a new instance of Firefox gets started with two content browsers (for example two tabs), the request to newSession never returns because because there's a race condition to do with the Marionette:register listener callback.

You can reproduce this in Firefox Nightly by creating a new profile, and running:

    ./firefox --P new-profile --no-remote --marionette

This will open the “Thank you for using Nightly” page as well as the usual Firefox start page.  This will confuse Marionette.

We don't experience this problem in our testing because we set preferences to not load these tabs and instead open a single tab with about:blank.  We should obviously support the eventuality that our real users will use a stock Firefox browser without these preferences set.