core: fix Attributes value equality

Fixes: #3857

core/src/main/java/io/grpc/Attributes.java

@@ -129,7 +129,18 @@ public final class Attributes {
       return false;
     }
     Attributes that = (Attributes) o;
-    return Objects.equal(data, that.data);
+    if (data.size() != that.data.size()) {
+      return false;
+    }
+    for (Entry<Key<?>, Object> e : data.entrySet()) {
+      if (!that.data.containsKey(e.getKey())) {
+        return false;
+      }
+      if (!Objects.equal(e.getValue(), that.data.get(e.getKey()))) {
+        return false;
+      }
+    }
+    return true;
   }
 
   /**

core/src/test/java/io/grpc/AttributesTest.java

@@ -17,6 +17,7 @@
 package io.grpc;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertSame;
 
 import org.junit.Test;
@@ -50,4 +51,20 @@ public class AttributesTest {
   public void empty() {
     assertEquals(0, Attributes.EMPTY.keys().size());
   }
+
+  @Test
+  @SuppressWarnings("BoxedPrimitiveConstructor")
+  public void valueEquality() {
+    Attributes.Key<Integer> key = Attributes.Key.of("ints");
+    Integer v1 = new Integer(100000);
+    Integer v2 = new Integer(100000);
+
+    assertNotSame(v1, v2);
+    assertEquals(v1, v2);
+
+    Attributes attr1 = Attributes.newBuilder().set(key, v1).build();
+    Attributes attr2 = Attributes.newBuilder().set(key, v2).build();
+
+    assertEquals(attr1, attr2);
+  }
 }