Bug 12720 Can't DND into non-source folder in Packages view
Build 20020321 In the Packages view, I can drag a file from the file system onto a project, a package or a source folder. However I cannot drag it onto a non-source folder. I can, however, drag the file onto the project, and then drag it into the non- source folder from within the packages view. The packages view should allow me to drag a file into any folder, just like in the Navigator view.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/FileTransferDropAdapter.java
if (!(isPackageFragment || isJavaProject || isPackageFragmentRoot)) 
			return;
			
		IJavaElement element= (IJavaElement)target;
		if (!element.isReadOnly()) 
			event.detail= DND.DROP_COPY;
			
		return;	
	}
	public void drop(Object javaTarget, DropTargetEvent event) {
		int operation= event.detail;
		
		event.detail= DND.DROP_NONE;
		Object data= event.data;
		if (data == null || operation != DND.DROP_COPY)
			return;
			
		IContainer target= null;
		try {
			target= (IContainer)((IJavaElement)javaTarget).getCorrespondingResource();	
		} catch (JavaModelException e) {
			return;
		}
		
		List files= checkFiles(SWTUtil.getShell(event.widget),(String[])data, target.getLocation());
		if (files.size() > 0) {
			Shell shell= JavaPlugin.getActiveWorkbenchShell();
			
			ImportOperation op= new ImportOperation(target.getFullPath(), FileSystemStructureProvider.INSTANCE, this, files);
			op.setCreateContainerStructure(false);