Bug 5571 JAR Packager: Reveal first checked project
If the list of projects in the JAR Packager is long it is possible that the shown projects are not checked even though there are checked projects (due to current selection). ==> reveal the first checked project.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/JarPackageWizardPage.java
* Create a list with the folders / projects that correspond
	 * to the Java elements (Java project, package, package root)
	 */
	private Set getCorrespondingContainers(Set elements) {
		Set javaElementResources= new HashSet(elements.size());
		Iterator iter= elements.iterator();
		while (iter.hasNext()) {
			Object element= iter.next();
			if (element instanceof IJavaElement) {
				IJavaElement je= (IJavaElement)element;
				int type= je.getElementType();
				if (type == IJavaElement.JAVA_PROJECT || type == IJavaElement.PACKAGE_FRAGMENT || type == IJavaElement.PACKAGE_FRAGMENT_ROOT) {
					
					if (!(type == IJavaElement.PACKAGE_FRAGMENT && ((IPackageFragment)element).isDefaultPackage())) {
						Object resource;
						try {
							resource= je.getCorrespondingResource();
						} catch (JavaModelException ex) {
							resource= null;
						}
						if (resource != null)
							javaElementResources.add(resource);
					}
				}
			}
		}
		return javaElementResources;
	}
}