Bug 197113 Project Explorer drag and drop selection not working properly
Create a new java project. Open Project Explorer. Create 2 new classes - Test1 and Test2. Close the java code editors. Select Test1.java in the project explorer. Select Test2.java by doing a mouse down only (so Test1.java still appears highlighted) then drag Test2.java into the code editor area ()- Test1.java is displayed. This only occurs in the Project Explorer, the package explorer works fine.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonViewer.java
/**
	 * <p>
	 * Initializes the content provider, label provider, and drag and drop
	 * support. Should not be called by clients -- this method is invoked when
	 * the constructor is invoked.
	 * </p>
	 */
	protected void init() {
		setUseHashlookup(true);
		setContentProvider(contentService.createCommonContentProvider());
		setLabelProvider(new NavigatorDecoratingLabelProvider(contentService.createCommonLabelProvider()));
		initDragAndDrop();
	}
	protected void removeWithoutRefresh(Object[] elements) {
		super.remove(elements);
	}
	/**
	 * <p>
	 * Adds DND support to the Navigator. Uses hooks into the extensible
	 * framework for DND.
	 * </p>
	 * <p>
	 * By default, the following Transfer types are supported:
	 * <ul>
	 * <li>LocalSelectionTransfer.getInstance(),
	 * <li>PluginTransfer.getInstance()
	 * </ul>
	 * </p>
	 * 
	 * @see CommonDragAdapter