Fix uncaught LEADING_HYPHEN IllegalArgumentException in host flows

This should have been getting turned into an InvalidHostNameException, but
wasn't. I've added tests for HostFlowUtils verifying the correct behavior for
this. Idn.toASCII() can throw IllegalArgumentException for some combinations
of input, including hostnames with a leading hyphen, so the call should be
inside the try block that turns IAEs into InvalidHostNameExceptions.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=139373849

java/google/registry/flows/host/HostFlowUtils.java

@@ -47,11 +47,11 @@ public class HostFlowUtils {
     if (!name.equals(hostNameLowerCase)) {
       throw new HostNameNotLowerCaseException(hostNameLowerCase);
     }
+    try {
       String hostNamePunyCoded = Idn.toASCII(name);
       if (!name.equals(hostNamePunyCoded)) {
         throw new HostNameNotPunyCodedException(hostNamePunyCoded);
       }
-    try {
       InternetDomainName hostName = InternetDomainName.from(name);
       if (!name.equals(hostName.toString())) {
         throw new HostNameNotNormalizedException(hostName.toString());

javatests/google/registry/flows/host/HostFlowUtilsTest.java

@@ -0,0 +1,76 @@
+// Copyright 2016 The Nomulus Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.flows.host;
+
+import static google.registry.flows.host.HostFlowUtils.validateHostName;
+
+import com.google.common.base.Strings;
+import google.registry.flows.host.HostFlowUtils.HostNameNotLowerCaseException;
+import google.registry.flows.host.HostFlowUtils.HostNameNotNormalizedException;
+import google.registry.flows.host.HostFlowUtils.HostNameNotPunyCodedException;
+import google.registry.flows.host.HostFlowUtils.HostNameTooLongException;
+import google.registry.flows.host.HostFlowUtils.HostNameTooShallowException;
+import google.registry.flows.host.HostFlowUtils.InvalidHostNameException;
+import google.registry.testing.AppEngineRule;
+import google.registry.testing.ExceptionRule;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link HostFlowUtils}. */
+@RunWith(JUnit4.class)
+public class HostFlowUtilsTest {
+
+  @Rule public final ExceptionRule thrown = new ExceptionRule();
+
+  @Rule public final AppEngineRule appEngine = AppEngineRule.builder().withDatastore().build();
+
+  @Test
+  public void test_validateHostName_hostNameTooLong() throws Exception {
+    thrown.expect(HostNameTooLongException.class);
+    validateHostName(Strings.repeat("na", 200) + ".wat.man");
+  }
+
+  @Test
+  public void test_validateHostName_hostNameNotLowerCase() throws Exception {
+    thrown.expect(HostNameNotLowerCaseException.class);
+    validateHostName("NA.CAPS.TLD");
+  }
+
+  @Test
+  public void test_validateHostName_hostNameNotPunyCoded() throws Exception {
+    thrown.expect(HostNameNotPunyCodedException.class);
+    validateHostName("motörhead.death.metal");
+  }
+
+  @Test
+  public void test_validateHostName_hostNameNotNormalized() throws Exception {
+    thrown.expect(HostNameNotNormalizedException.class);
+    validateHostName("root.node.yeah.");
+  }
+
+  @Test
+  public void test_validateHostName_hostNameHasLeadingHyphen() throws Exception {
+    thrown.expect(InvalidHostNameException.class);
+    validateHostName("-giga.mega.tld");
+  }
+
+  @Test
+  public void test_validateHostName_hostNameTooShallow() throws Exception {
+    thrown.expect(HostNameTooShallowException.class);
+    validateHostName("domain.tld");
+  }
+}