From 9352d4867843a84f584f4527acde216431823499 Mon Sep 17 00:00:00 2001
From: Alisha Kim <pril@pril.cc>
Date: Sun, 17 Dec 2023 20:03:18 +0900
Subject: [PATCH] Fixed packet corruption issue when enum was not 4 bytes.

Signed-off-by: Alisha Kim <pril@pril.cc>
---
 src/MySqlConnector/MySqlParameter.cs          | 40 ++++++++++++++-
 tests/MySqlConnector.Tests/DummyEnum.cs       | 50 ++++++++++++++++++-
 .../MySqlConnector.Tests.csproj               |  2 +-
 .../MySqlParameterAppendBinaryTests.cs        | 27 ++++++++++
 4 files changed, 116 insertions(+), 3 deletions(-)
 create mode 100644 tests/MySqlConnector.Tests/MySqlParameterAppendBinaryTests.cs

diff --git a/src/MySqlConnector/MySqlParameter.cs b/src/MySqlConnector/MySqlParameter.cs
index 841051780..34100b5bd 100644
--- a/src/MySqlConnector/MySqlParameter.cs
+++ b/src/MySqlConnector/MySqlParameter.cs
@@ -835,7 +835,45 @@ internal void AppendBinary(ByteBufferWriter writer, StatementPreparerOptions opt
 		}
 		else if (Value is Enum)
 		{
-			writer.Write(Convert.ToInt32(Value, CultureInfo.InvariantCulture));
+			var enumType = Value.GetType();
+			var enumUnderlyingType = enumType.GetEnumUnderlyingType();
+
+			if (enumUnderlyingType == typeof(byte))
+			{
+				writer.Write((byte) Value);
+			}
+			else if (enumUnderlyingType == typeof(sbyte))
+			{
+				writer.Write(unchecked((byte) (sbyte) Value));
+			}
+			else if (enumUnderlyingType == typeof(short))
+			{
+				writer.Write(unchecked((ushort) (short) Value));
+			}
+			else if (enumUnderlyingType == typeof(ushort))
+			{
+				writer.Write((ushort) Value);
+			}
+			else if (enumUnderlyingType == typeof(int))
+			{
+				writer.Write((int) Value);
+			}
+			else if (enumUnderlyingType == typeof(uint))
+			{
+				writer.Write((uint) Value);
+			}
+			else if (enumUnderlyingType == typeof(long))
+			{
+				writer.Write(unchecked((ulong) (long) Value));
+			}
+			else if (enumUnderlyingType == typeof(ulong))
+			{
+				writer.Write((ulong) Value);
+			}
+			else
+			{
+				throw new NotSupportedException($"Parameter type {Value.GetType().Name} is not supported; see https://fl.vu/mysql-param-type. Value: {Value}");
+			}
 		}
 		else if (MySqlDbType == MySqlDbType.Int16)
 		{
diff --git a/tests/MySqlConnector.Tests/DummyEnum.cs b/tests/MySqlConnector.Tests/DummyEnum.cs
index 70b580905..627e5e0c1 100644
--- a/tests/MySqlConnector.Tests/DummyEnum.cs
+++ b/tests/MySqlConnector.Tests/DummyEnum.cs
@@ -4,4 +4,52 @@ internal enum DummyEnum
 {
 	FirstValue,
 	SecondValue
-} 
+}
+
+internal enum DummyByteEnum : byte
+{
+	FirstValue,
+	SecondValue = 0x11,
+}
+
+internal enum DummySByteEnum : sbyte
+{
+	FirstValue,
+	SecondValue = 0x11,
+}
+
+internal enum DummyShortEnum : short
+{
+	FirstValue,
+	SecondValue = 0x1122,
+}
+
+internal enum DummyUShortEnum : ushort
+{
+	FirstValue,
+	SecondValue = 0x1122,
+}
+
+internal enum DummyIntEnum : int
+{
+	FirstValue,
+	SecondValue = 0x11223344,
+}
+
+internal enum DummyUIntEnum : uint
+{
+	FirstValue,
+	SecondValue = 0x11223344,
+}
+
+internal enum DummyLongEnum : long
+{
+	FirstValue,
+	SecondValue = 0x11223344_55667788,
+}
+
+internal enum DummyULongEnum : ulong
+{
+	FirstValue,
+	SecondValue = 0x11223344_55667788,
+}
diff --git a/tests/MySqlConnector.Tests/MySqlConnector.Tests.csproj b/tests/MySqlConnector.Tests/MySqlConnector.Tests.csproj
index 8eddd9566..fed6d961c 100644
--- a/tests/MySqlConnector.Tests/MySqlConnector.Tests.csproj
+++ b/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;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="ByteBufferWriterTests.cs;CachedProcedureTests.cs;CancellationTests.cs;ColumnCountPayloadTests.cs;ColumnReaderTests.cs;ConnectionTests.cs;FakeMySqlServer.cs;FakeMySqlServerConnection.cs;LoadBalancerTests.cs;MySqlDecimalTests.cs;MySqlExceptionTests.cs;MySqlParameterAppendBinaryTests.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" />
diff --git a/tests/MySqlConnector.Tests/MySqlParameterAppendBinaryTests.cs b/tests/MySqlConnector.Tests/MySqlParameterAppendBinaryTests.cs
new file mode 100644
index 000000000..948332773
--- /dev/null
+++ b/tests/MySqlConnector.Tests/MySqlParameterAppendBinaryTests.cs
@@ -0,0 +1,27 @@
+using MySqlConnector.Protocol.Serialization;
+
+namespace MySqlConnector.Tests;
+
+public class MySqlParameterAppendBinaryTests
+{
+	[Theory]
+	[InlineData(DummySByteEnum.SecondValue, MySqlDbType.Byte, new byte[] { 0x11 })]
+	[InlineData(DummyByteEnum.SecondValue, MySqlDbType.UByte, new byte[] { 0x11 })]
+	[InlineData(DummyShortEnum.SecondValue, MySqlDbType.Int16, new byte[] { 0x22, 0x11 })]
+	[InlineData(DummyUShortEnum.SecondValue, MySqlDbType.UInt16, new byte[] { 0x22, 0x11 })]
+	[InlineData(DummyIntEnum.SecondValue, MySqlDbType.Int32, new byte[] { 0x44, 0x33, 0x22, 0x11 })]
+	[InlineData(DummyUIntEnum.SecondValue, MySqlDbType.UInt32, new byte[] { 0x44, 0x33, 0x22, 0x11 })]
+	[InlineData(DummyEnum.SecondValue, MySqlDbType.Int32, new byte[] { 0x01, 0x00, 0x00, 0x00 })]
+	[InlineData(DummyLongEnum.SecondValue, MySqlDbType.Int64, new byte[] { 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 })]
+	[InlineData(DummyULongEnum.SecondValue, MySqlDbType.UInt64, new byte[] { 0x88, 0x77, 0x66, 0x55, 0x44, 0x33, 0x22, 0x11 })]
+	public void WriteBinaryEnumType(object value, MySqlDbType expectedMySqlDbType, byte[] expectedBinary)
+	{
+		var parameter = new MySqlParameter { Value = value };
+		var writer = new ByteBufferWriter();
+		parameter.AppendBinary(writer, StatementPreparerOptions.None);
+
+		Assert.Equal(parameter.MySqlDbType, expectedMySqlDbType);
+		Assert.Equal(writer.Position, expectedBinary.Length);
+		Assert.Equal(writer.ArraySegment, expectedBinary);
+	}
+}