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 clear() {
		fElements= null;
		fSelection= null;
		fMoveRefactoring= null;
		fCanMoveElements= 0;
		fCopyRefactoring= null;
		fCanCopyElements= 0;
	}
	
	public void validateDrop(Object target, DropTargetEvent event, int operation) {
		event.detail= DND.DROP_NONE;
		
		if (tooFast(event)) 
			return;
		
		initializeSelection();
				
		try {
			if (operation == DND.DROP_DEFAULT) {
				event.detail= handleValidateDefault(target, event);
			} else if (operation == DND.DROP_COPY) {
				event.detail= handleValidateCopy(target, event);
			} else if (operation == DND.DROP_MOVE) {
				event.detail= handleValidateMove(target, event);
			} else if (operation == DND.DROP_LINK) {
				event.detail= handleValidateLink(target, event);
			}
		} catch (JavaModelException e){