Bug 41443 overview ruler not working
smoke test for 20030812 The overview ruler in the Java editor does not work when starting with a fresh workspace as described in the smoke test scenario.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
* @return the default reference provider
	 * @since R3.0
	 */
	private IQuickDiffProviderImplementation getDefaultReferenceProvider() {
		String defaultID= getPreferenceStore().getString(PreferenceConstants.QUICK_DIFF_DEFAULT_PROVIDER);
		EditorsPlugin editorPlugin= EditorsPlugin.getDefault();
		ReferenceProviderDescriptor[] descs= editorPlugin.getExtensions();
		IQuickDiffProviderImplementation provider= null;
		
		for (int i= 0; i < descs.length; i++) {
			if (descs[i].getId().equals(defaultID)) {
				provider= descs[i].createProvider();
				if (provider != null) {
					provider.setActiveEditor(this);
					if (provider.isEnabled())
						break;
					provider.dispose();
					provider= null;
				}
			}
		}
		
		if (provider == null) {
			ReferenceProviderDescriptor defaultDescriptor= editorPlugin.getDefaultProvider();
			if (defaultDescriptor != null) {
				provider= defaultDescriptor.createProvider();
				if (provider != null) {
					provider.setActiveEditor(this);
					if (!provider.isEnabled()) {
						provider.dispose();