See bug 280959, comment 72 until bug 280959, comment 76. When checking the mochitest for bug 280959, it caused failures when the Prototype testcase was run before it, while the mochitest for bug 280959 worked fine standalone. So there is definitely something wacky going on here. I managed to extract the relevant tests and will try to minimize it further. Now to reproduce the test error: - Open "test_Prototype.html", after 10 seconds, it automatically redirects to "test_bug280959.html". Expected result: Passed: 24 Failed: 0 Actual result: Passed: 19 Failed: 5 These are the tests that are failing: not ok - copy event firing on DOM element not ok - copy on DOM element set clipboard correctly not ok - cut event firing on DOM element not ok - paste event firing on DOM element not ok - copy event (to-be-cancelled) firing on DOM element Running the "test_bug280959.html" file standalone doesn't cause these test failures.

Bug 418457 removed support for onbeforecut/copy/paste, so this should be WFM, feel free to reopen if you think there are remaining issues.

https://bugzilla.mozilla.org/show_bug.cgi?id=1472046 Move all DOM bugs that haven’t been updated in more than 3 years and has no one currently assigned to P5. If you have questions, please contact :mdaly.