Wiki - Don't lose unsaved changes when you navigate
While editing a wiki and the back button or location change event occurs, all unsaved wiki changes are lost. I've experienced this a few times editing a wiki; click the preview tab and accidentally click the back button losing my writing.
Match how this is handled when you are editing an issue. You are able to navigate away from the edit page with unsaved changes. However, when you return, the unsaved edits are still there, ready for you to continue and/or save.