Unable to get Version 5.1.7 (7534.57.2, r121382) to complete the quit cycle. The heading "Safari" will remain highlighted while Quit is greyed out. This condition will remain until Bug Report is filled out then the crash message will appear.
Created attachment 149875 [details] Show state of WebKit while hung trying to Quit
*** This bug has been marked as a duplicate of bug 90093 ***