Track parameter name changes. Fixes #811

Author: bgrainger

src/MySqlConnector/MySql.Data.MySqlClient/MySqlParameter.cs

@@ -121,7 +121,9 @@ public override string ParameterName
 			set
 			{
 				m_name = value ?? "";
-				NormalizedParameterName = value is null ? "" : NormalizeParameterName(m_name);
+				var newNormalizedParameterName = value is null ? "" : NormalizeParameterName(m_name);
+				ParameterCollection?.ChangeParameterName(this, NormalizedParameterName, newNormalizedParameterName);
+				NormalizedParameterName = newNormalizedParameterName;
 			}
 		}
 
@@ -205,6 +207,8 @@ private MySqlParameter(MySqlParameter other, string parameterName)
 
 		internal string NormalizedParameterName { get; private set; }
 
+		internal MySqlParameterCollection? ParameterCollection { get; set; }
+
 		internal void AppendSqlString(ByteBufferWriter writer, StatementPreparerOptions options)
 		{
 			var noBackslashEscapes = (options & StatementPreparerOptions.NoBackslashEscapes) == StatementPreparerOptions.NoBackslashEscapes;

src/MySqlConnector/MySql.Data.MySqlClient/MySqlParameterCollection.cs

@@ -68,6 +68,8 @@ public MySqlParameter AddWithValue(string parameterName, object? value)
 
 		public override void Clear()
 		{
+			foreach (var parameter in m_parameters)
+				parameter.ParameterCollection = null;
 			m_parameters.Clear();
 			m_nameToIndex.Clear();
 		}
@@ -113,6 +115,7 @@ public override void RemoveAt(int index)
 			var oldParameter = m_parameters[index];
 			if (oldParameter.NormalizedParameterName is object)
 				m_nameToIndex.Remove(oldParameter.NormalizedParameterName);
+			oldParameter.ParameterCollection = null;
 			m_parameters.RemoveAt(index);
 
 			foreach (var pair in m_nameToIndex.ToList())
@@ -130,9 +133,11 @@ protected override void SetParameter(int index, DbParameter value)
 			var oldParameter = m_parameters[index];
 			if (oldParameter.NormalizedParameterName is object)
 				m_nameToIndex.Remove(oldParameter.NormalizedParameterName);
+			oldParameter.ParameterCollection = null;
 			m_parameters[index] = newParameter;
 			if (newParameter.NormalizedParameterName is object)
 				m_nameToIndex.Add(newParameter.NormalizedParameterName, index);
+			newParameter.ParameterCollection = this;
 		}
 
 		protected override void SetParameter(string parameterName, DbParameter value) => SetParameter(IndexOf(parameterName), value);
@@ -153,13 +158,29 @@ protected override void SetParameter(int index, DbParameter value)
 			set => SetParameter(name, value);
 		}
 
+		internal void ChangeParameterName(MySqlParameter parameter, string oldName, string newName)
+		{
+			if (m_nameToIndex.TryGetValue(oldName, out var index) && m_parameters[index] == parameter)
+				m_nameToIndex.Remove(oldName);
+			else
+				index = m_parameters.IndexOf(parameter);
+
+			if (newName.Length != 0)
+			{
+				if (m_nameToIndex.ContainsKey(newName))
+					throw new MySqlException(@"There is already a parameter with the name '{0}' in this collection.".FormatInvariant(parameter.ParameterName));
+				m_nameToIndex[newName] = index;
+			}
+		}
+
 		private void AddParameter(MySqlParameter parameter)
 		{
 			if (!string.IsNullOrEmpty(parameter.NormalizedParameterName) && NormalizedIndexOf(parameter.NormalizedParameterName) != -1)
 				throw new MySqlException(@"Parameter '{0}' has already been defined.".FormatInvariant(parameter.ParameterName));
 			m_parameters.Add(parameter);
 			if (!string.IsNullOrEmpty(parameter.NormalizedParameterName))
 				m_nameToIndex[parameter.NormalizedParameterName] = m_parameters.Count - 1;
+			parameter.ParameterCollection = this;
 		}
 
 		readonly List<MySqlParameter> m_parameters;

tests/SideBySide/ParameterCollection.cs

@@ -257,6 +257,53 @@ public void CopyToIndexOutOfRange()
 			Assert.Throws<ArgumentException>(() => m_parameterCollection.CopyTo(new DbParameter[2], 3));
 		}
 
+		[Fact]
+		public void ChangeParameterNameAfterAdd()
+		{
+			using var cmd = new MySqlCommand();
+			using var cmd2 = new MySqlCommand();
+			var parameter = cmd.CreateParameter();
+			parameter.ParameterName = "@a";
+
+			cmd2.Parameters.Add(parameter);
+			cmd.Parameters.Add(parameter);
+
+			parameter.ParameterName = "@b";
+
+			Assert.Equal(parameter, cmd.Parameters["@b"]);
+			Assert.Throws<ArgumentException>(() => cmd.Parameters["@a"]);
+
+			// only works for the last collection that contained the parameter
+			Assert.Throws<ArgumentException>(() => cmd2.Parameters["@b"]);
+			Assert.Equal(parameter, cmd2.Parameters["@a"]);
+		}
+
+		[Fact]
+		public void SetParameterNameAfterAdd()
+		{
+			using var cmd = new MySqlCommand();
+			var parameter = cmd.CreateParameter();
+			cmd.Parameters.Add(parameter);
+			parameter.ParameterName = "@a";
+			Assert.Equal(parameter, cmd.Parameters["@a"]);
+		}
+
+		[Fact]
+		public void SetTwoParametersToSameNAme()
+		{
+			using var cmd = new MySqlCommand();
+			var parameter1 = cmd.CreateParameter();
+			cmd.Parameters.Add(parameter1);
+			var parameter2 = cmd.CreateParameter();
+			cmd.Parameters.Add(parameter2);
+			parameter1.ParameterName = "@a";
+#if !BASELINE
+			Assert.Throws<MySqlException>(() => parameter2.ParameterName = "@a");
+#else
+			Assert.Throws<ArgumentException>(() => parameter2.ParameterName = "@a");
+#endif
+		}
+
 		MySqlCommand m_command;
 		MySqlParameterCollection m_parameterCollection;
 	}