mozilla-b2g/gaia — pull request #22295 by cctuan (2014-07-30 07:53:00+00:00)
Title: Bug 1045919 - JavaScript Error: "TypeError: AppWindowManager.getActiveApp(...) is null" {file: "app://system.gaiamobile.org/js/activity_window_manager.js"

https://bugzilla.mozilla.org/show_bug.cgi?id=1045919