Bug 123496 [IDE] Use operation validation API for IDE actions
We should use the Resources/Core operation validation API in the IDE actions for manipulating resources.
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/CopyFilesAndFoldersOperation.java
return null;
		}
		IWorkspace workspace = destination.getWorkspace();
		IResource linkHandle = createLinkedResourceHandle(destination, source);
		IStatus locationStatus = workspace.validateLinkLocation(linkHandle,
				source.getRawLocation());
		if (locationStatus.getSeverity() == IStatus.ERROR) {
			return locationStatus.getMessage();
		}
		IPath sourceLocation = source.getLocation();
		if (source.getProject().equals(destination.getProject()) == false
				&& source.getType() == IResource.FOLDER
				&& sourceLocation != null) {
			
			
			try {
				IResource[] members = destination.members();
				for (int j = 0; j < members.length; j++) {
					if (sourceLocation.equals(members[j].getLocation())
							&& source.getName().equals(members[j].getName())) {
						return NLS
								.bind(
										IDEWorkbenchMessages.CopyFilesAndFoldersOperation_sameSourceAndDest,
										source.getName());
					}
				}
			} catch (CoreException exception) {
				displayError(NLS
						.bind(
								IDEWorkbenchMessages.CopyFilesAndFoldersOperation_internalError,