Implement AutoEnlist connection string option.

Author: bgrainger

src/MySqlConnector/MySqlClient/MySqlConnection.cs

@@ -161,7 +161,7 @@ private async Task OpenAsync(IOBehavior ioBehavior, CancellationToken cancellati
 			}
 
 #if !NETSTANDARD1_3
-			if (System.Transactions.Transaction.Current != null)
+			if (m_connectionSettings.AutoEnlist && System.Transactions.Transaction.Current != null)
 				EnlistTransaction(System.Transactions.Transaction.Current);
 #endif
 		}

src/MySqlConnector/MySqlClient/MySqlConnectionStringBuilder.cs

@@ -110,6 +110,12 @@ public bool AllowUserVariables
 			set => MySqlConnectionStringOption.AllowUserVariables.SetValue(this, value);
 		}
 
+		public bool AutoEnlist
+		{
+			get => MySqlConnectionStringOption.AutoEnlist.GetValue(this);
+			set => MySqlConnectionStringOption.AutoEnlist.SetValue(this, value);
+		}
+
 		public bool BufferResultSets
 		{
 			get => MySqlConnectionStringOption.BufferResultSets.GetValue(this);
@@ -243,6 +249,7 @@ internal abstract class MySqlConnectionStringOption
 
 		// Other Options
 		public static readonly MySqlConnectionStringOption<bool> AllowUserVariables;
+		public static readonly MySqlConnectionStringOption<bool> AutoEnlist;
 		public static readonly MySqlConnectionStringOption<bool> BufferResultSets;
 		public static readonly MySqlConnectionStringOption<string> CharacterSet;
 		public static readonly MySqlConnectionStringOption<uint> ConnectionTimeout;
@@ -345,6 +352,10 @@ static MySqlConnectionStringOption()
 				keys: new[] { "AllowUserVariables", "Allow User Variables" },
 				defaultValue: false));
 
+			AddOption(AutoEnlist = new MySqlConnectionStringOption<bool>(
+				keys: new[] { "AutoEnlist", "Auto Enlist" },
+				defaultValue: true));
+
 			AddOption(BufferResultSets = new MySqlConnectionStringOption<bool>(
 				keys: new[] { "BufferResultSets", "Buffer Result Sets" },
 				defaultValue: false));

src/MySqlConnector/Serialization/ConnectionSettings.cs

@@ -46,6 +46,7 @@ public ConnectionSettings(MySqlConnectionStringBuilder csb)
 
 			// Other Options
 			AllowUserVariables = csb.AllowUserVariables;
+			AutoEnlist = csb.AutoEnlist;
 			BufferResultSets = csb.BufferResultSets;
 			ConnectionTimeout = (int)csb.ConnectionTimeout;
 			ConvertZeroDateTime = csb.ConvertZeroDateTime;
@@ -87,6 +88,7 @@ private ConnectionSettings(ConnectionSettings other, bool? useCompression)
 
 			// Other Options
 			AllowUserVariables = other.AllowUserVariables;
+			AutoEnlist = other.AutoEnlist;
 			BufferResultSets = other.BufferResultSets;
 			ConnectionTimeout = other.ConnectionTimeout;
 			ConvertZeroDateTime = other.ConvertZeroDateTime;
@@ -124,6 +126,7 @@ private ConnectionSettings(ConnectionSettings other, bool? useCompression)
 
 		// Other Options
 		internal readonly bool AllowUserVariables;
+		internal readonly bool AutoEnlist;
 		internal readonly bool BufferResultSets;
 		internal readonly int ConnectionTimeout;
 		internal readonly bool ConvertZeroDateTime;

tests/MySqlConnector.Tests/MySqlConnectionStringBuilderTests.cs

@@ -11,6 +11,7 @@ public void Defaults()
 		{
 			var csb = new MySqlConnectionStringBuilder();
 			Assert.Equal(false, csb.AllowUserVariables);
+			Assert.Equal(true, csb.AutoEnlist);
 			Assert.Equal(null, csb.CertificateFile);
 			Assert.Equal(null, csb.CertificatePassword);
 			Assert.Equal("", csb.CharacterSet);
@@ -54,35 +55,37 @@ public void ParseConnectionString()
 			var csb = new MySqlConnectionStringBuilder
 			{
 				ConnectionString = "Data Source=db-server;" +
-				                   "Initial Catalog=schema_name;" +
-				                   "Allow User Variables=true;" +
-				                   "certificate file=file.pfx;" +
-				                   "certificate password=Pass1234;" +
-				                   "Character Set=latin1;" +
-				                   "Compress=true;" +
-				                   "connect timeout=30;" +
-				                   "connection lifetime=15;" +
-				                   "ConnectionReset=false;" +
-				                   "Convert Zero Datetime=true;" +
+					"Initial Catalog=schema_name;" +
+					"Allow User Variables=true;" +
+					"auto enlist=False;" +
+					"certificate file=file.pfx;" +
+					"certificate password=Pass1234;" +
+					"Character Set=latin1;" +
+					"Compress=true;" +
+					"connect timeout=30;" +
+					"connection lifetime=15;" +
+					"ConnectionReset=false;" +
+					"Convert Zero Datetime=true;" +
 #if !BASELINE
-				                   "connectionidletimeout=30;" +
-				                   "bufferresultsets=true;" +
-				                   "forcesynchronous=true;" +
+					"connectionidletimeout=30;" +
+					"bufferresultsets=true;" +
+					"forcesynchronous=true;" +
 #endif
-				                   "Keep Alive=90;" +
-				                   "minpoolsize=5;" +
-				                   "maxpoolsize=15;" +
-				                   "OldGuids=true;" +
-				                   "persistsecurityinfo=yes;" +
-				                   "Pooling=no;" +
-				                   "Port=1234;" +
-				                   "pwd=Pass1234;" +
-				                   "Treat Tiny As Boolean=false;" +
-				                   "ssl mode=verifyca;" +
-				                   "Uid=username;" +
-				                   "useaffectedrows=false"
+					"Keep Alive=90;" +
+					"minpoolsize=5;" +
+					"maxpoolsize=15;" +
+					"OldGuids=true;" +
+					"persistsecurityinfo=yes;" +
+					"Pooling=no;" +
+					"Port=1234;" +
+					"pwd=Pass1234;" +
+					"Treat Tiny As Boolean=false;" +
+					"ssl mode=verifyca;" +
+					"Uid=username;" +
+					"useaffectedrows=false"
 			};
 			Assert.Equal(true, csb.AllowUserVariables);
+			Assert.Equal(false, csb.AutoEnlist);
 			Assert.Equal("file.pfx", csb.CertificateFile);
 			Assert.Equal("Pass1234", csb.CertificatePassword);
 			Assert.Equal("latin1", csb.CharacterSet);

tests/SideBySide/TransactionScopeTests.cs

@@ -195,6 +195,57 @@ public void ThrowExceptionAfterCompleteInTransaction()
 			Assert.Equal(new[] { 1, 2 }, values);
 		}
 
+		[Fact]
+		public void AutoEnlistFalseWithCommit()
+		{
+			m_database.Connection.Execute(@"drop table if exists transaction_scope_test;
+				create table transaction_scope_test(value integer not null);");
+
+			using (var transactionScope = new TransactionScope())
+			using (var conn = new MySqlConnection(AppConfig.ConnectionString + ";auto enlist=false"))
+			{
+				conn.Open();
+				using (var dbTransaction = conn.BeginTransaction())
+				{
+					conn.Execute("insert into transaction_scope_test(value) values(1), (2);");
+
+					dbTransaction.Commit();
+					transactionScope.Complete();
+				}
+			}
+
+			var values = m_database.Connection.Query<int>(@"select value from transaction_scope_test order by value;").ToList();
+			Assert.Equal(new[] { 1, 2 }, values);
+		}
+
+		[Fact]
+		public void AutoEnlistFalseWithoutCommit()
+		{
+			m_database.Connection.Execute(@"drop table if exists transaction_scope_test;
+				create table transaction_scope_test(value integer not null);");
+
+			using (var transactionScope = new TransactionScope())
+			using (var conn = new MySqlConnection(AppConfig.ConnectionString + ";auto enlist=false"))
+			{
+				conn.Open();
+				using (var dbTransaction = conn.BeginTransaction())
+				{
+					conn.Execute("insert into transaction_scope_test(value) values(1), (2);");
+
+#if BASELINE
+					// With Connector/NET a MySqlTransaction can't roll back after TransactionScope has been completed;
+					// workaround is to explicitly dispose it first. In MySqlConnector (with AutoEnlist=false) they have
+					// independent lifetimes.
+					dbTransaction.Dispose();
+#endif
+					transactionScope.Complete();
+				}
+			}
+
+			var values = m_database.Connection.Query<int>(@"select value from transaction_scope_test order by value;").ToList();
+			Assert.Equal(new int[0], values);
+		}
+
 		[Fact
 #if BASELINE
 		(Skip = "Multiple simultaneous connections or connections with different connection strings inside the same transaction are not currently supported.")