The editor doesn't seem to know when a paste occurs.
Example: Open a new editor (either to write a new post or to edit an existing one), and paste some text as the first thing you do. Notice that the undo button is not enabled and Ctrl+Z (since it is overridden by the editor) doesn't work either. You can right-click in the textarea and select "undo", since the editor doesn't override that.
As a sidenote, why is the editor even handling undo? All the browsers already do that anyway.
Update: I've tested on all the browsers I have here on my work PC (WinXP SP3).
- Internet Explorer 8.0.6001.18702: Non-reproducible
- Safari 4 Public Beta (528.17): Reproduced
- Opera 9.64: Reproduced
- Firefox 3.5.5: Reproduced
- Chrome 22.214.171.124: Reproduced
In addition, on Safari, Chrome, and Firefox, pasting twice in a row enables the edit button, while in Opera I can paste all day and it is never enabled. Also, if the pastes are not consecutive (i.e. if I paste, click elsewhere, and paste again) the undo button is not enabled in Safari/Chrome/Firefox.