Bug 29698 drag and drop of java files between packages in package explorer doesn't work
the <preview> <ok> <cancel> dialog shows up, but <ok> has the same effect as <cancel> and <preview> would only show movements of files and no changes in imports of other java files. on <ok> in the preview it only moves the file(s) (as indicated ) without changing referencing imports.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/SelectionTransferDropAdapter.java
private void pasteSourceReferences(final Object target, DropTargetEvent event) {
		SelectionDispatchAction pasteAction= ReorgActionFactory.createPasteAction(getDragableSourceReferences(), target);
		pasteAction.update(pasteAction.getSelection());
		if (!pasteAction.isEnabled()){
			event.detail= DND.DROP_NONE;
			return;
		}	
		pasteAction.run();	
		
		return;
	}
	
	private int handleValidateCopy(Object target, DropTargetEvent event) throws JavaModelException{
		if (canPasteSourceReferences(target))
			return DND.DROP_COPY;
		
		if (fCopyRefactoring == null)
			fCopyRefactoring= new CopyRefactoring(fElements, new CopyQueries());
		
		if (!canCopyElements())
			return DND.DROP_NONE;	
		if (fCopyRefactoring.isValidDestination(target))
			return DND.DROP_COPY;
		else
			return DND.DROP_NONE;					
	}
	private boolean canMoveSelectedSourceReferences(Object target) throws JavaModelException{
		ICompilationUnit targetCu= getCompilationUnit(target);
		if (targetCu == null)
			return false;