A script such as this <BODY onfocus="alert('la la la')"> causes Mozilla to lock up until i kill the process!
Browser, not engine. Reassigning to Event Handling for further triage.
IE4.7 does not go into an infinite loop on the testcase. NN4.7 goes into an infinite loop if you load the testcase, Alt+Tab to some other application, then Alt+Tab back to NN4.7 Moz also infinite-loops, if you bring the mouse to focus on the body -
*** This bug has been marked as a duplicate of 58441 ***
QA contact updated