Bug 232777 [Viewers] ViewerDropAdapter holds currentTarget forever
Build ID: 3.3.2 Member currentTarget should be set to null after drop or after cancel, because it holds a domain object, which can't be garbage collected after Viewer.setInput(null).
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ViewerDropAdapter.java
break;
            }
        }
        
         
		if (!selectFeedbackEnabled) {
			event.feedback &= ~DND.FEEDBACK_SELECT;
		}
		if (expandEnabled) {
			event.feedback |= DND.FEEDBACK_EXPAND;
		}
		if (scrollEnabled) {
			event.feedback |= DND.FEEDBACK_SCROLL;
		}
    }
    /**
	 * Sets whether visible insertion feedback should be presented to the user.
	 * <p>
	 * Typical insertion feedback is the horizontal insertion bars that appear
	 * between adjacent items while dragging.
	 * </p>
	 * 
	 * @param value
	 *            <code>true</code> if visual feedback is desired, and
	 *            <code>false</code> if not
	 */
    public void setFeedbackEnabled(boolean value) {
        feedbackEnabled = value;
    }
    /**