Bug #10281 Clone issue with MySqlConnection
Submitted: 30 Apr 2005 16:00 Modified: 8 Jun 2005 21:55
Reporter: Roberto Rabe Email Updates:
Status: Closed Impact on me:
Category:Connector / NET Severity:S2 (Serious)
Version:1.0.4 OS:Windows (XP Pro (SP2))
Assigned to: Reggie Burnett CPU Architecture:Any

[30 Apr 2005 16:00] Roberto Rabe
See Bug #7478 for original comment.

Cloning a connection throws an unhandled exception if the original MySqlConnection still has the default ConnectionString Hashtable values. 

How to repeat:
Simple/quick ConnectionTests NUnit test to throw exception:

public void TestConnectionClone()
	MySqlConnection c = new MySqlConnection();
	MySqlConnection clone = (MySqlConnection) ((ICloneable)c).Clone();

MySql.Data.MySqlClient.Tests.ConnectionTests.TestConnectionClone :
System.NullReferenceException : Object reference not set to an instance of an

   at MySql.Data.MySqlClient.MySqlConnectionString.CreateConnectionString() in
\MySqlClient\ConnectionString.cs:line 300
   at MySql.Data.MySqlClient.MySqlConnectionString.GetConnectionString() in
\MySqlClient\ConnectionString.cs:line 261
   at MySql.Data.MySqlClient.MySqlConnection.get_ConnectionString() in
\MySqlClient\Connection.cs:line 172
   at MySql.Data.MySqlClient.MySqlConnection.System.ICloneable.Clone() in
\MySqlClient\Connection.cs:line 344
   at MySql.Data.MySqlClient.Tests.ConnectionTests.TestConnectionClone() in
\testsuite\connectiontests.cs:line 50

Suggested fix:
ConnectionString.CreateConnectionString() throws exception when looping through keys and gets to "charset" key:

/// <summary>
/// Uses the values in the keyValues hash to create a
/// connection string
/// </summary>
/// <returns></returns>
public string CreateConnectionString()
	string cStr = String.Empty;

	Hashtable values = (Hashtable)keyValues.Clone();
	Hashtable defaultValues = GetDefaultValues();

	if (!PersistSecurityInfo && values.Contains("password") )
		values.Remove( "password" );

	// we always return the server key.  It's not needed but 
	// seems weird for it not to be there.
	cStr = "server=" + values["host"] + ";";

	foreach (string key in values.Keys)
		if (!values[key].Equals( defaultValues[key]))
			cStr += key + "=" + values[key] + ";";

	return cStr;

Fix by checking for charset null (or any undefined value) in loop before grabbing values[key] to append to cStr.

[17 May 2005 8:43] Vasily Kishkin
Could you send any example test suit for this bug with using CreateConnectionString() ?
[17 May 2005 21:43] Roberto Rabe
Not sure why an additional test is needed for CreateConnectionString().  The error happens when clone is called and a connection string had not yet been set on the original connection.  The TestConnectionClone() is a really simple and quick test that shows the error.

[17 May 2005 22:16] Roberto Rabe
Hmmm...maybe this was missed in my original post:

public void TestConnectionClone()
	MySqlConnection c = new MySqlConnection();
	MySqlConnection clone = (MySqlConnection) ((ICloneable)c).Clone();
[17 May 2005 22:17] Roberto Rabe
That test was near the top of the original post.
[28 May 2005 6:30] Vasily Kishkin
Tested on Win 2000 Sp4, Microsoft Visual C# .NET , Connector .NET 1.0.4 Test case is in text.
[7 Jun 2005 16:56] Reggie Burnett
Thank you for your bug report. This issue has been committed to our
source repository of that product and will be incorporated into the
next release.

If necessary, you can access the source repository and build the latest
available version, including the bugfix, yourself. More information 
about accessing the source trees is available at

Additional info:

Fixed in 1.0.5
[8 Jun 2005 21:55] Mike Hillyer
Documented in Connector/NET changelog.
[15 Jun 2005 14:30] Wout Huntjens
I got the latest version with the command "bk clone http://mysql.bkbits.net/connector-net connector-net
". In this version the problem seems not to be fixed. Did you checkin the change already??