Fix Java maps reflection to call onChange to populate changes to parent

builders.

Change-Id: Ibf6ae3c0fe6bc31f74b8018c81a5af461b1c24ea

java/src/main/java/com/google/protobuf/GeneratedMessage.java

@@ -2171,10 +2171,12 @@ public abstract class GeneratedMessage extends AbstractMessage
       }
 
       public void setRepeated(Builder builder, int index, Object value) {
+        builder.onChanged();
         getMapField(builder).getMutableList().set(index, (Message) value);
       }
 
       public void addRepeated(Builder builder, Object value) {
+        builder.onChanged();
         getMapField(builder).getMutableList().add((Message) value);
       }
 
@@ -2197,6 +2199,7 @@ public abstract class GeneratedMessage extends AbstractMessage
       }
 
       public void clear(Builder builder) {
+        builder.onChanged();
         getMapField(builder).getMutableList().clear();
       }
 
@@ -2395,7 +2398,8 @@ public abstract class GeneratedMessage extends AbstractMessage
           final Class<? extends GeneratedMessage> messageClass,
           final Class<? extends Builder> builderClass,
           final String containingOneofCamelCaseName) {
-        super(descriptor, camelCaseName, messageClass, builderClass, containingOneofCamelCaseName);
+        super(descriptor, camelCaseName, messageClass, builderClass,
+            containingOneofCamelCaseName);
 
         newBuilderMethod = getMethodOrDie(type, "newBuilder");
         getBuilderMethodBuilder =

java/src/test/java/com/google/protobuf/MapTest.java

@@ -301,6 +301,45 @@ public class MapTest extends TestCase {
     assertEquals(0, message.getOptionalMessage().getInt32ToInt32Field().size());
   }
 
+  public void testNestedBuilderOnChangeEventPropagationReflection() {
+    FieldDescriptor intMapField = f("int32_to_int32_field");
+    // Create an outer message builder with nested builder.
+    TestOnChangeEventPropagation.Builder parentBuilder =
+        TestOnChangeEventPropagation.newBuilder();
+    TestMap.Builder testMapBuilder = parentBuilder.getOptionalMessageBuilder();
+
+    // Create a map entry message.
+    TestMap.Builder entryBuilder = TestMap.newBuilder();
+    entryBuilder.getMutableInt32ToInt32Field().put(1, 1);
+
+    // Put the entry into the nested builder.
+    testMapBuilder.addRepeatedField(
+        intMapField, entryBuilder.getRepeatedField(intMapField, 0));
+
+    // Should be able to observe the change.
+    TestOnChangeEventPropagation message = parentBuilder.build();
+    assertEquals(1, message.getOptionalMessage().getInt32ToInt32Field().size());
+
+    // Change the entry value.
+    entryBuilder.getMutableInt32ToInt32Field().put(1, 4);
+    testMapBuilder = parentBuilder.getOptionalMessageBuilder();
+    testMapBuilder.setRepeatedField(
+        intMapField, 0, entryBuilder.getRepeatedField(intMapField, 0));
+
+    // Should be able to observe the change.
+    message = parentBuilder.build();
+    assertEquals(4,
+        message.getOptionalMessage().getInt32ToInt32Field().get(1).intValue());
+
+    // Clear the nested builder.
+    testMapBuilder = parentBuilder.getOptionalMessageBuilder();
+    testMapBuilder.clearField(intMapField);
+
+    // Should be able to observe the change.
+    message = parentBuilder.build();
+    assertEquals(0, message.getOptionalMessage().getInt32ToInt32Field().size());
+  }
+
   // The following methods are used to test reflection API.
 
   private static FieldDescriptor f(String name) {