Bug 48364 PreferenceDialog can reopen empty
20031209 When you close the Preferences dialog with an entry other than the default selected you will get an empty entry in the dialog when you reopen STEPS 1) Open the preferences dialog 2) Select the Appearances page 3) Close the dialog 4) Reopen - Workbench will be selected and the contents will be empty
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
/**
	 * @param control the <code>Control</code> to lay out.
	 * @since 3.0
	 */
	protected void layoutTreeAreaControl(Control control) {
		GridData gd = new GridData(GridData.FILL_VERTICAL);
		gd.widthHint = 150;
		gd.verticalSpan = 2;
		control.setLayoutData(gd);
	}
	/**
	 * The preference dialog implementation of this <code>Dialog</code>
	 * framework method sends <code>performOk</code> to all pages of the 
	 * preference dialog, then calls <code>handleSave</code> on this dialog
	 * to save any state, and then calls <code>close</code> to close
	 * this dialog.
	 */
	protected void okPressed() {
		
		Iterator nodes = preferenceManager.getElements(PreferenceManager.PRE_ORDER).iterator();
		while (nodes.hasNext()) {
			IPreferenceNode node = (IPreferenceNode) nodes.next();
			IPreferencePage page = node.getPage();
			if (page != null) {
				if (!page.performOk())
					return;
			}
		}