Change ReadTag and PeekTag to just use 0 as a return value for "end of stream", rather than using an awkward out parameter.

This simplifies quite a lot of code.

Generated code in next commit.

4 files changed, 26 insertions, 20 deletions

diff --git a/csharp/src/Google.Protobuf.Test/CodedInputStreamExtensions.cs b/csharp/src/Google.Protobuf.Test/CodedInputStreamExtensions.cs
index 408c7cb9..23af2887 100644
--- a/csharp/src/Google.Protobuf.Test/CodedInputStreamExtensions.cs
+++ b/csharp/src/Google.Protobuf.Test/CodedInputStreamExtensions.cs
@@ -38,8 +38,7 @@ namespace Google.Protobuf
     {
         public static void AssertNextTag(this CodedInputStream input, uint expectedTag)
         {
-            uint tag;
-            Assert.IsTrue(input.ReadTag(out tag));
+            uint tag = input.ReadTag();
             Assert.AreEqual(expectedTag, tag);
         }
 
diff --git a/csharp/src/Google.Protobuf.Test/CodedInputStreamTest.cs b/csharp/src/Google.Protobuf.Test/CodedInputStreamTest.cs
index 6e25fa37..c4c92efd 100644
--- a/csharp/src/Google.Protobuf.Test/CodedInputStreamTest.cs
+++ b/csharp/src/Google.Protobuf.Test/CodedInputStreamTest.cs
@@ -279,9 +279,7 @@ namespace Google.Protobuf
             ms.Position = 0;

 

             CodedInputStream input = new CodedInputStream(ms);

-            uint testtag;

-            Assert.IsTrue(input.ReadTag(out testtag));

-            Assert.AreEqual(tag, testtag);

+            Assert.AreEqual(tag, input.ReadTag());

 

             // TODO(jonskeet): Should this be ArgumentNullException instead?

             Assert.Throws<InvalidProtocolBufferException>(() => input.ReadBytes());

@@ -377,9 +375,7 @@ namespace Google.Protobuf
 

             CodedInputStream input = new CodedInputStream(ms);

 

-            uint actualTag;

-            Assert.IsTrue(input.ReadTag(out actualTag));

-            Assert.AreEqual(tag, actualTag);

+            Assert.AreEqual(tag, input.ReadTag());

             string text = input.ReadString();

             Assert.AreEqual('\ufffd', text[0]);

         }

@@ -430,15 +426,21 @@ namespace Google.Protobuf
                 ms.Position = 0;

                 CodedInputStream input = new CodedInputStream(ms, new byte[ms.Length / 2]);

 

-                uint tag;

-                Assert.IsTrue(input.ReadTag(out tag));

+                uint tag = input.ReadTag();

                 Assert.AreEqual(1, WireFormat.GetTagFieldNumber(tag));

                 Assert.AreEqual(100, input.ReadBytes().Length);

 

-                Assert.IsTrue(input.ReadTag(out tag));

+                tag = input.ReadTag();

                 Assert.AreEqual(2, WireFormat.GetTagFieldNumber(tag));

                 Assert.AreEqual(100, input.ReadBytes().Length);

             }

         }

+

+        [Test]

+        public void Tag0Throws()

+        {

+            var input = new CodedInputStream(new byte[] { 0 });

+            Assert.Throws<InvalidProtocolBufferException>(() => input.ReadTag());

+        }

     }

 }
\ No newline at end of file
diff --git a/csharp/src/Google.Protobuf.Test/CodedOutputStreamTest.cs b/csharp/src/Google.Protobuf.Test/CodedOutputStreamTest.cs
index af329174..c1bf7bd6 100644
--- a/csharp/src/Google.Protobuf.Test/CodedOutputStreamTest.cs
+++ b/csharp/src/Google.Protobuf.Test/CodedOutputStreamTest.cs
@@ -335,15 +335,16 @@ namespace Google.Protobuf
             // Now test Input stream:

             {

                 CodedInputStream cin = new CodedInputStream(new MemoryStream(bytes), new byte[50]);

-                uint tag;

                 Assert.AreEqual(0, cin.Position);

                 // Field 1:

-                Assert.IsTrue(cin.ReadTag(out tag) && tag >> 3 == 1);

+                uint tag = cin.ReadTag();

+                Assert.AreEqual(1, tag >> 3);

                 Assert.AreEqual(1, cin.Position);

                 Assert.AreEqual(500, cin.ReadInt32());

                 Assert.AreEqual(3, cin.Position);

                 //Field 2:

-                Assert.IsTrue(cin.ReadTag(out tag) && tag >> 3 == 2);

+                tag = cin.ReadTag();

+                Assert.AreEqual(2, tag >> 3);

                 Assert.AreEqual(4, cin.Position);

                 int childlen = cin.ReadLength();

                 Assert.AreEqual(120, childlen);

@@ -353,19 +354,22 @@ namespace Google.Protobuf
                 // Now we are reading child message

                 {

                     // Field 11: numeric value: 500

-                    Assert.IsTrue(cin.ReadTag(out tag) && tag >> 3 == 11);

+                    tag = cin.ReadTag();

+                    Assert.AreEqual(11, tag >> 3);

                     Assert.AreEqual(6, cin.Position);

                     Assert.AreEqual(500, cin.ReadInt32());

                     Assert.AreEqual(8, cin.Position);

                     //Field 12: length delimited 120 bytes

-                    Assert.IsTrue(cin.ReadTag(out tag) && tag >> 3 == 12);

+                    tag = cin.ReadTag();

+                    Assert.AreEqual(12, tag >> 3);

                     Assert.AreEqual(9, cin.Position);

                     ByteString bstr = cin.ReadBytes();

                     Assert.AreEqual(110, bstr.Length);

                     Assert.AreEqual((byte) 109, bstr[109]);

                     Assert.AreEqual(120, cin.Position);

                     // Field 13: fixed numeric value: 501

-                    Assert.IsTrue(cin.ReadTag(out tag) && tag >> 3 == 13);

+                    tag = cin.ReadTag();

+                    Assert.AreEqual(13, tag >> 3);

                     // ROK - Previously broken here, this returned 126 failing to account for bufferSizeAfterLimit

                     Assert.AreEqual(121, cin.Position);

                     Assert.AreEqual(501, cin.ReadSFixed32());

@@ -375,7 +379,8 @@ namespace Google.Protobuf
                 cin.PopLimit(oldlimit);

                 Assert.AreEqual(125, cin.Position);

                 // Field 3: fixed numeric value: 501

-                Assert.IsTrue(cin.ReadTag(out tag) && tag >> 3 == 3);

+                tag = cin.ReadTag();

+                Assert.AreEqual(3, tag >> 3);

                 Assert.AreEqual(126, cin.Position);

                 Assert.AreEqual(501, cin.ReadSFixed32());

                 Assert.AreEqual(130, cin.Position);

diff --git a/csharp/src/Google.Protobuf.Test/Collections/RepeatedFieldTest.cs b/csharp/src/Google.Protobuf.Test/Collections/RepeatedFieldTest.cs
index 322100d0..8c804fdd 100644
--- a/csharp/src/Google.Protobuf.Test/Collections/RepeatedFieldTest.cs
+++ b/csharp/src/Google.Protobuf.Test/Collections/RepeatedFieldTest.cs
@@ -455,7 +455,7 @@ namespace Google.Protobuf.Collections
             Assert.AreEqual(0, output.SpaceLeft);
 
             CodedInputStream input = new CodedInputStream(bytes);
-            Assert.IsTrue(input.ReadTag(out tag));
+            tag = input.ReadTag();
 
             RepeatedField<SampleEnum> values = new RepeatedField<SampleEnum>();
             values.AddEntriesFrom(input, FieldCodec.ForEnum(tag, x => (int)x, x => (SampleEnum)x));
@@ -493,7 +493,7 @@ namespace Google.Protobuf.Collections
             Assert.AreEqual(0, output.SpaceLeft);
 
             CodedInputStream input = new CodedInputStream(bytes);
-            Assert.IsTrue(input.ReadTag(out tag));
+            tag = input.ReadTag();
 
             RepeatedField<SampleEnum> values = new RepeatedField<SampleEnum>();
             values.AddEntriesFrom(input, FieldCodec.ForEnum(tag, x => (int)x, x => (SampleEnum)x));