Handle missing metadata (#1399)

Create ColumnCountPayload when metadata are missing.

Co-authored-by: Bradley Grainger <[email protected]>

Author: trejjam

src/MySqlConnector/Protocol/Payloads/ColumnCountPayload.cs

@@ -22,7 +22,7 @@ public static ColumnCountPayload Create(ReadOnlySpan<byte> span, bool supportsOp
 	{
 		var reader = new ByteArrayReader(span);
 		var columnCount = (int) reader.ReadLengthEncodedInteger();
-		var metadataFollows = !supportsOptionalMetadata || reader.ReadByte() == 1;
+		var metadataFollows = !supportsOptionalMetadata || reader.BytesRemaining == 0 || reader.ReadByte() == 1;
 		return new ColumnCountPayload(columnCount, metadataFollows);
 	}
 }

tests/MySqlConnector.Tests/ColumnCountPayloadTests.cs

@@ -0,0 +1,21 @@
+using MySqlConnector.Protocol.Payloads;
+
+namespace MySqlConnector.Tests;
+
+public class ColumnCountPayloadTests
+{
+	[Theory]
+	[InlineData(new byte[] { 1 }, false, 1, true)]
+	[InlineData(new byte[] { 1, 1 }, true, 1, true)]
+	[InlineData(new byte[] { 1, 0 }, true, 1, false)]
+	[InlineData(new byte[] { 2 }, false, 2, true)]
+	[InlineData(new byte[] { 2, 1 }, true, 2, true)]
+	[InlineData(new byte[] { 2, 0 }, true, 2, false)]
+	[InlineData(new byte[] { 2 }, true, 2, true)] // this seems like invalid data, but a server may return this
+	public void ParseResultSetHeader(byte[] span, bool supportsOptionalMetadata, int expectedColumnCount, bool expectedMetadataFollows)
+	{
+		var columnCountPayload = ColumnCountPayload.Create(span.AsSpan(), supportsOptionalMetadata);
+		Assert.Equal(expectedColumnCount, columnCountPayload.ColumnCount);
+		Assert.Equal(expectedMetadataFollows, columnCountPayload.MetadataFollows);
+	}
+}

tests/MySqlConnector.Tests/MySqlConnector.Tests.csproj

@@ -47,7 +47,7 @@
 
   <ItemGroup Condition=" '$(Configuration)' == 'MySqlData' ">
     <PackageReference Include="MySql.Data" />
-    <Compile Remove="ByteBufferWriterTests.cs;CachedProcedureTests.cs;CancellationTests.cs;ColumnReaderTests.cs;ConnectionTests.cs;FakeMySqlServer.cs;FakeMySqlServerConnection.cs;LoadBalancerTests.cs;MySqlDecimalTests.cs;MySqlExceptionTests.cs;MySqlParameterCollectionNameToIndexTests.cs;NormalizeTests.cs;ServerVersionTests.cs;StatementPreparerTests.cs;TypeMapperTests.cs;UtilityTests.cs" />
+    <Compile Remove="ByteBufferWriterTests.cs;CachedProcedureTests.cs;CancellationTests.cs;ColumnCountPayloadTests.cs;ColumnReaderTests.cs;ConnectionTests.cs;FakeMySqlServer.cs;FakeMySqlServerConnection.cs;LoadBalancerTests.cs;MySqlDecimalTests.cs;MySqlExceptionTests.cs;MySqlParameterCollectionNameToIndexTests.cs;NormalizeTests.cs;ServerVersionTests.cs;StatementPreparerTests.cs;TypeMapperTests.cs;UtilityTests.cs" />
     <Compile Remove="Metrics\*.cs" />
     <Using Include="MySql.Data.MySqlClient" />
     <Using Include="MySql.Data.Types" />