Fix problem in cursorUpdateCache when homeLine is invalid. (This may happen after _breakAllLines before we update homeLine.)
Fix problem in cursorUpdateCache when homeLine is invalid.
(This may happen after _breakAllLines before we update homeLine.)

rwhogg/DomTerm,rwhogg/DomTerm,rwhogg/DomTerm,rwhogg/DomTerm,rwhogg/DomTerm,rwhogg/DomTerm