rem: for (var i = 0; i < this.mAttendees.length; i++) this.mAttendees[i].makeImmutable(); 
add: if (this.mAttendees) { for (var i = 0; i < this.mAttendees.length; i++) this.mAttendees[i].makeImmutable(); } 
context:     makeItemBaseImmutable: function() {        if (this.mImmutable)            throw Components.results.NS_ERROR_OBJECT_IS_IMMUTABLE;        // make all our components immutable        if (this.mRecurrenceInfo)            this.mRecurrenceInfo.makeImmutable();        if (this.mOrganizer)            this.mOrganizer.makeImmutable();        for (var i = 0; i < this.mAttendees.length; i++)            this.mAttendees[i].makeImmutable();        var e = this.mProperties.enumerator;        while (e.hasMoreElements()) {            var prop = e.getNext().QueryInterface(Components.interfaces.nsIProperty);            var val = prop.value;            if (prop.value instanceof Components.interfaces.calIDateTime) {                if (prop.value.isMutable)                    prop.value.makeImmutable();            }        }        if (this.alarmOffset) {            this.alarmOffset.makeImmutable();            if (this.alarmLastAck) {                this.alarmLastAck.makeImmutable();            }        }        this.ensureNotDirty();        this.mImmutable = true;    },
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/921ddb5c87288ef109b3faf5ad15de1dd165e20b/calItemBase.js/buggy/calendar/base/src/calItemBase.js