JmxMetricExporter fails to export discovery metrics

java.lang.StringIndexOutOfBoundsException: String index out of range: -2

	at java.lang.String.substring(String.java:1931)
	at org.apache.ignite.spi.metric.jmx.MetricRegistryMBean.lambda$getMBeanInfo$0(MetricRegistryMBean.java:105)
	at java.util.Iterator.forEachRemaining(Iterator.java:116)
	at org.apache.ignite.spi.metric.jmx.MetricRegistryMBean.getMBeanInfo(MetricRegistryMBean.java:85)
	at org.apache.ignite.spi.metric.jmx.MetricRegistryMBean.getAttribute(MetricRegistryMBean.java:58)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getAttribute(DefaultMBeanServerInterceptor.java:647)
	at com.sun.jmx.mbeanserver.JmxMBeanServer.getAttribute(JmxMBeanServer.java:678)
	at javax.management.MBeanServerInvocationHandler.invoke(MBeanServerInvocationHandler.java:273)
	at com.sun.proxy.$Proxy32.getMBeanInfo(Unknown Source)
	at org.apache.ignite.internal.metric.JmxExporterSpiTest.test(JmxExporterSpiTest.java:146)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.apache.ignite.testframework.junits.GridAbstractTest$7.run(GridAbstractTest.java:2391)
	at java.lang.Thread.run(Thread.java:748)

/** {@inheritDoc} */
@Override protected IgniteConfiguration getConfiguration(String igniteInstanceName) throws Exception {
    IgniteConfiguration cfg = super.getConfiguration(igniteInstanceName);

    JmxMetricExporterSpi jmxSpi = new JmxMetricExporterSpi();

    cfg.setMetricExporterSpi(jmxSpi);

    return cfg;
}

/** */
@Test
public void test() throws Exception {
    IgniteEx srv = startGrid();
    DynamicMBean mBean = metricRegistry(srv.name(), "io", "discovery");

    mBean.getMBeanInfo();
}