Remove LabelId#equals() and hashCode()

Somehow the equals implementation got broken in Ibb162a6a. There
shouldn't have even been an opportunity for a copy-paste error, since
we should have just used the implementations from StringKey.

Add a tiny test to verify key behavior.

Change-Id: Idf91cc7142d160f6abeb5b1365490b73728fde0e

gerrit-reviewdb/BUCK

@@ -29,8 +29,10 @@ java_test(
   srcs = glob([TESTS + 'client/**/*.java']),
   deps = [
     ':client',
+    '//lib:guava',
     '//lib:gwtorm',
     '//lib:junit',
+    '//lib:truth',
   ],
   source_under_test = [':client'],
   visibility = ['//tools/eclipse:classpath'],

gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/LabelId.java

@@ -41,17 +41,4 @@ public class LabelId extends StringKey<com.google.gwtorm.client.Key<?>> {
   protected void set(String newValue) {
     id = newValue;
   }
-
-  @Override
-  public int hashCode() {
-    return get().hashCode();
-  }
-
-  @Override
-  public boolean equals(Object b) {
-    if (this == b) {
-      return get().equals(((LabelId) b).get());
-    }
-    return false;
-  }
 }

gerrit-reviewdb/src/test/java/com/google/gerrit/reviewdb/client/PatchSetApprovalTest.java

@@ -0,0 +1,63 @@
+// Copyright (C) 2015 The Android Open Source Project
+//
+// 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 com.google.gerrit.reviewdb.client;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.gwtorm.client.KeyUtil;
+import com.google.gwtorm.server.StandardKeyEncoder;
+
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class PatchSetApprovalTest {
+  static {
+    KeyUtil.setEncoderImpl(new StandardKeyEncoder());
+  }
+
+  @Test
+  public void keyEquality() {
+    PatchSetApproval.Key k1 = new PatchSetApproval.Key(
+        new PatchSet.Id(new Change.Id(1), 2),
+        new Account.Id(3),
+        new LabelId("My-Label"));
+    PatchSetApproval.Key k2 = new PatchSetApproval.Key(
+        new PatchSet.Id(new Change.Id(1), 2),
+        new Account.Id(3),
+        new LabelId("My-Label"));
+    PatchSetApproval.Key k3 = new PatchSetApproval.Key(
+        new PatchSet.Id(new Change.Id(1), 2),
+        new Account.Id(3),
+        new LabelId("Other-Label"));
+
+    assertThat(k2).isEqualTo(k1);
+    assertThat(k3).isNotEqualTo(k1);
+    assertThat(k2.hashCode()).isEqualTo(k1.hashCode());
+    assertThat(k3.hashCode()).isNotEqualTo(k1.hashCode());
+
+    Map<PatchSetApproval.Key, String> map = new HashMap<>();
+    map.put(k1, "k1");
+    map.put(k2, "k2");
+    map.put(k3, "k3");
+    assertThat(map).containsKey(k1);
+    assertThat(map).containsKey(k2);
+    assertThat(map).containsKey(k3);
+    assertThat(map).containsEntry(k1, "k2");
+    assertThat(map).containsEntry(k2, "k2");
+    assertThat(map).containsEntry(k3, "k3");
+  }
+}