Bug 91899 [Markers] IMarker.setAttribute fails when attributeName = IMarker.LOCATION
Calling setAttribute(IMarker.LOCATION, "foo") on an IMarker instance does nothing---the "Location" column in the Problem View remains blank.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/FieldLineNumber.java
if (marker.getLine() < 0) {
            return ""; 
        }
        return NLS.bind(
        		MarkerMessages.label_lineNumber,
        		Integer.toString(marker.getLine()));
        
    }
    /*
     *  (non-Javadoc)
     * @see org.eclipse.ui.views.markers.internal.IField#getImage(java.lang.Object)
     */
    public Image getImage(Object obj) {
        return null;
    }
    /*
     *  (non-Javadoc)
     * @see org.eclipse.ui.views.markers.internal.IField#compare(java.lang.Object, java.lang.Object)
     */
    public int compare(Object obj1, Object obj2) {
        if (obj1 == null || obj2 == null || !(obj1 instanceof ConcreteMarker)
                || !(obj2 instanceof ConcreteMarker)) {
            return 0;
        }
        ConcreteMarker marker1 = (ConcreteMarker) obj1;
        ConcreteMarker marker2 = (ConcreteMarker) obj2;
        return marker1.getLine() - marker2.getLine();
    }
}