Preventing incorrectly shown unload alert
Preventing incorrectly shown unload alert

issue #1327

- IE9 fires an unload when using Backbone.history.navigate which meant the alert always got shown on first save when the url changes from from /editor/ to /editor/id. Not sure if other browsers do this, but this workaround fixes it

TryGhost/Ghost,TryGhost/Ghost,TryGhost/Ghost