Fix merging with message-valued oneof

If messages A and B have the same oneof case, which is a message
type, and we merge B into A, those sub-messages should be merged.

Fixes #3200.

Note that I haven't regenerated all the code, as some of the protos
have been changed, breaking generation.

1 files changed, 13 insertions, 1 deletions

diff --git a/csharp/src/Google.Protobuf.Test/IssuesTest.cs b/csharp/src/Google.Protobuf.Test/IssuesTest.cs
index a38d6b08..2caf80a9 100644
--- a/csharp/src/Google.Protobuf.Test/IssuesTest.cs
+++ b/csharp/src/Google.Protobuf.Test/IssuesTest.cs
@@ -33,7 +33,7 @@
 using Google.Protobuf.Reflection;

 using UnitTest.Issues.TestProtos;

 using NUnit.Framework;

-

+using static UnitTest.Issues.TestProtos.OneofMerging.Types;

 

 namespace Google.Protobuf

 {

@@ -78,5 +78,17 @@ namespace Google.Protobuf
             Assert.AreEqual("{ \"name\": \"test\", \"desc\": \"test2\", \"exid\": \"test3\" }",

                 JsonFormatter.Default.Format(message));

         }

+

+        [Test]

+        public void OneofMerging()

+        {

+            var message1 = new OneofMerging { Nested = new Nested { X = 10 } };

+            var message2 = new OneofMerging { Nested = new Nested { Y = 20 } };

+            var expected = new OneofMerging { Nested = new Nested { X = 10, Y = 20 } };

+

+            var merged = message1.Clone();

+            merged.MergeFrom(message2);

+            Assert.AreEqual(expected, merged);

+        }

     }

 }