Steps to reproduce: 1) Go to http://webkit.org 2) Open the console 3) Enter "foo = 42;" or "var foo=42" Actual results: SyntaxError: Parse error Expected results: 42 (result of the assignation) "foo=42" (without ;) works...
http://trac.webkit.org/changeset/35834 is certainly the suspect.
Rolled out the problem change in r35895. Maybe there is a way to fix bug 20428 and not have this side affect. But bug 20428 was not that critical. The user can always add the parenthesis if they want.