Consume unknown fields when parsing.

This is expected to be the cause of the conformance test failures.
Generated code in next commit.

3 files changed, 64 insertions, 1 deletions

diff --git a/csharp/src/Google.Protobuf.Test/GeneratedMessageTest.cs b/csharp/src/Google.Protobuf.Test/GeneratedMessageTest.cs
index 2b6265c1..1ef3d753 100644
--- a/csharp/src/Google.Protobuf.Test/GeneratedMessageTest.cs
+++ b/csharp/src/Google.Protobuf.Test/GeneratedMessageTest.cs
@@ -36,6 +36,8 @@ using Google.Protobuf.TestProtos;
 using NUnit.Framework;

 using System.Collections;

 using System.Collections.Generic;

+using System.Linq;

+using Google.Protobuf.WellKnownTypes;

 

 namespace Google.Protobuf

 {

@@ -590,5 +592,32 @@ namespace Google.Protobuf
             Assert.AreEqual(message, message2);

             Assert.AreEqual(TestAllTypes.OneofFieldOneofCase.OneofUint32, message2.OneofFieldCase);

         }

+

+        [Test]

+        public void IgnoreUnknownFields_RealDataStillRead()

+        {

+            var message = SampleMessages.CreateFullTestAllTypes();

+            var stream = new MemoryStream();

+            var output = new CodedOutputStream(stream);

+            var unusedFieldNumber = 23456;

+            Assert.IsFalse(TestAllTypes.Descriptor.Fields.InDeclarationOrder().Select(x => x.FieldNumber).Contains(unusedFieldNumber));

+            output.WriteTag(unusedFieldNumber, WireFormat.WireType.LengthDelimited);

+            output.WriteString("ignore me");

+            message.WriteTo(output);

+            output.Flush();

+

+            stream.Position = 0;

+            var parsed = TestAllTypes.Parser.ParseFrom(stream);

+            Assert.AreEqual(message, parsed);

+        }

+

+        [Test]

+        public void IgnoreUnknownFields_AllTypes()

+        {

+            // Simple way of ensuring we can skip all kinds of fields.

+            var data = SampleMessages.CreateFullTestAllTypes().ToByteArray();

+            var empty = Empty.Parser.ParseFrom(data);

+            Assert.AreEqual(new Empty(), empty);

+        }

     }

 }

diff --git a/csharp/src/Google.Protobuf/CodedInputStream.cs b/csharp/src/Google.Protobuf/CodedInputStream.cs
index a1abfcb0..fee31e3b 100644
--- a/csharp/src/Google.Protobuf/CodedInputStream.cs
+++ b/csharp/src/Google.Protobuf/CodedInputStream.cs
@@ -309,6 +309,39 @@ namespace Google.Protobuf
         }

 

         /// <summary>

+        /// Consumes the data for the field with the tag we've just read.

+        /// This should be called directly after <see cref="ReadTag"/>, when

+        /// the caller wishes to skip an unknown field.

+        /// </summary>

+        public void ConsumeLastField()

+        {

+            if (lastTag == 0)

+            {

+                throw new InvalidOperationException("ConsumeLastField cannot be called at the end of a stream");

+            }

+            switch (WireFormat.GetTagWireType(lastTag))

+            {

+                case WireFormat.WireType.StartGroup:

+                case WireFormat.WireType.EndGroup:

+                    // TODO: Work out how to skip them instead? See issue 688.

+                    throw new InvalidProtocolBufferException("Group tags not supported by proto3 C# implementation");

+                case WireFormat.WireType.Fixed32:

+                    ReadFixed32();

+                    break;

+                case WireFormat.WireType.Fixed64:

+                    ReadFixed64();

+                    break;

+                case WireFormat.WireType.LengthDelimited:

+                    var length = ReadLength();

+                    SkipRawBytes(length);

+                    break;

+                case WireFormat.WireType.Varint:

+                    ReadRawVarint32();

+                    break;

+            }

+        }

+

+        /// <summary>

         /// Reads a double field from the stream.

         /// </summary>

         public double ReadDouble()

diff --git a/src/google/protobuf/compiler/csharp/csharp_message.cc b/src/google/protobuf/compiler/csharp/csharp_message.cc
index 6ea568ca..ea722455 100644
--- a/src/google/protobuf/compiler/csharp/csharp_message.cc
+++ b/src/google/protobuf/compiler/csharp/csharp_message.cc
@@ -428,7 +428,8 @@ void MessageGenerator::GenerateMergingMethods(io::Printer* printer) {
     "  if (pb::WireFormat.IsEndGroupTag(tag)) {\n"
     "    return;\n"
     "  }\n"
-    "  break;\n"); // Note: we're ignoring unknown fields here.
+    "  input.ConsumeLastField();\n" // We're not storing the data, but we still need to consume it.
+    "  break;\n");
   for (int i = 0; i < fields_by_number().size(); i++) {
     const FieldDescriptor* field = fields_by_number()[i];
     internal::WireFormatLite::WireType wt =