Bug 65276 [Preferences] Preference dialog should disable OK when okPressed
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
IPreferencePage page = node.getPage();
						if (page != null) {
							if (!page.performOk())
								return;
						}
					}
				} catch (Exception e) {
					handleException(e);
				} finally {
					
					
					if (!errorOccurred)
						handleSave();
					
					close();
				}
			}
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.core.runtime.ISafeRunnable#handleException(java.lang.Throwable)
			 */
			public void handleException(Throwable e) {
				errorOccurred = true;
				if (Platform.isRunning()) {
					String bundle = Platform.PI_RUNTIME;
					Platform.getLog(Platform.getBundle(bundle)).log(
							new Status(IStatus.ERROR, bundle, 0, e.toString(),
									e));
				} else