Bug 167619 [Undo] 'Undo Delete Resources' should not be available after full project deletion
I20061212-0010. When deleting a project with all its contents there's a comment in the dialog that I cannot undo (OK). Once the project is gone I can still undo the project which is unexpected. Undoing the deletion results in an empty project which can be in a completely weird state (e.g. a Java project without a .classpath file). Adding Markus to track whether deleting from the Package Explorer is affected too.
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/DeleteResourceAction.java
* 
	 * @param resources
	 *            the selected resources
	 * @return <code>true</code> if the resources contains only non-projects,
	 *         and <code>false</code> otherwise
	 */
	private boolean containsOnlyNonProjects(IResource[] resources) {
		int types = getSelectedResourceTypes(resources);
		
		if (types == 0) {
			return false;
		}
		
		return (types & IResource.PROJECT) == 0;
	}
	/**
	 * Returns whether the selection contains only projects.
	 * 
	 * @param resources
	 *            the selected resources
	 * @return <code>true</code> if the resources contains only projects, and
	 *         <code>false</code> otherwise
	 */
	private boolean containsOnlyProjects(IResource[] resources) {
		int types = getSelectedResourceTypes(resources);
		
		return types == IResource.PROJECT;
	}
	/**
	 * Asks the user to confirm a delete operation.