User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.0.3) Gecko/2008092414 Firefox/3.0.3 Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.0.3) Gecko/2008092414 Firefox/3.0.3 Common usability guidelines suggest that the Undo option should apply to any kind of destructive action. One of the most destructive actions you can perform with a web browser is closing a window or a tab, yet the Undo option does not apply to these. It is true that there's a "Recently Closed Tabs" menu that applies to windows that have more than one window open. That's good. It is also true that if you try to close a window with multiple tabs, you get a warning that lets you cancel closing the window. That's good too. But if you accidentally close a window with a single tab, there's no warning, the tab doesn't show up in "Recently Closed Tabs", and the history provides no option to sort by when the document was closed. That means if you accidentally close a window with a single tab, and you don't know how to get back to where you were, you are completely and utterly out of luck. Obviously, something besides the undo needs to be fixed, but for sure, the Undo should do its job properly and let the user undo all destructive actions (with the exception possibly of quitting the browser), and closing windows should be near the top of the list. Reproducible: Always Steps to Reproduce: 1. 2. 3.

Sounds more like bug 394759 than bug 460360.