Reverts third_party/protobuf: Update to HEAD (f52e188fe4)

third_party/protobuf/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java

Index: third_party/protobuf/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
diff --git a/third_party/protobuf/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java b/third_party/protobuf/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
index 813fe6bc69688ae0dff654265f1a26cfd0b0b70b..8d1de6dc810ec5f7a90b626f986f9957892925c2 100644
--- a/third_party/protobuf/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
+++ b/third_party/protobuf/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
@@ -31,12 +31,15 @@
 package com.google.protobuf;
 
 import static protobuf_unittest.UnittestProto.optionalInt32Extension;
+import static protobuf_unittest.UnittestProto.optionalInt64Extension;
 
 import protobuf_unittest.UnittestProto.TestAllExtensions;
 import protobuf_unittest.UnittestProto.TestAllTypes;
-import java.io.IOException;
+
 import junit.framework.TestCase;
 
+import java.io.IOException;
+
 /**
  * Unit test for {@link LazyFieldLite}.
  *
@@ -218,6 +221,29 @@ public class LazyFieldLiteTest extends TestCase {
     assertEquals(messageWithExtensions, field.getValue(TestAllExtensions.getDefaultInstance()));
   }
 
+  public void testMergeMightLoseExtensions() throws Exception {
+    // Test that we don't know about the extensions when parsing.
+    TestAllExtensions message1 =
+        TestAllExtensions.newBuilder().setExtension(optionalInt32Extension, 1).build();
+    TestAllExtensions message2 =
+        TestAllExtensions.newBuilder().setExtension(optionalInt64Extension, 2L).build();
+
+    LazyFieldLite field = LazyFieldLite.fromValue(message1);
+    field.merge(LazyFieldLite.fromValue(message2));
+
+    // We lose the extensions from message 2 because we have to serialize it and then parse it
+    // again, using the empty registry this time.
+    TestAllExtensions value =
+        (TestAllExtensions) field.getValue(TestAllExtensions.getDefaultInstance());
+    assertTrue(value.hasExtension(optionalInt32Extension));
+    assertEquals(Integer.valueOf(1), value.getExtension(optionalInt32Extension));
+    assertFalse(value.hasExtension(optionalInt64Extension));
+
+    // The field is still there, it is just unknown.
+    assertTrue(value.getUnknownFields()
+        .hasField(optionalInt64Extension.getDescriptor().getNumber()));
+  }
+
 
   // Help methods.