MySQL Bugs: #24957: MySql.Data.Types.MySqlConversionException is not marked as Serializable.

Bug #24957	MySql.Data.Types.MySqlConversionException is not marked as Serializable.
Submitted:	11 Dec 2006 16:40	Modified:	27 Feb 2007 12:24
Reporter:	John Vanderburg
Status:	Closed
Category:	Connector/Net	Severity:	S3 (Non-critical)
Version:	5.0.2	OS:	Microsoft Windows (Win XP SP2)
Assigned to:		Target Version:
Tags:	remoting, date, time, exception

Description:
When MySqlConversionException is raised in a remote object, the client application
receives a SerializationException exception instead.  Information related to the actual
exception is not available to the client application.

Workarounds for this problem are very easy, including:

1. Following the information in the documentation 23.2.5.6. Handling Date and Time
Information in Connector/NET
(http://dev.mysql.com/doc/refman/5.0/en/connector-net-using-datetime.html)

2. Handling the exception in the remote object possibly raising another exception which is
remotable.

How to repeat:
Note:  This isn't very detailed and dosn't go into any detail on the issues with remoting.
 The actual issue is related to .NET remoting and well documented.  If necessary I can
create a sample.

1. Create a table with a date column and insert a row with a date .NET considers invalid,
such as '0000-00-00'.
2. Create a class derived from MarshalByRef which uses MySQL Connector/Net to read the
row.
3. Create a host program to activate the class created in step 2.
4. Create a client application to create an instance of the remote object and call the
method to read the "invalid" date.

Suggested fix:
Add [Serializable] attribute to MySqlConversionException class as follows:

In MySqlConversionException.cs:
    [Serializable]    // Add attribute
    public class MySqlConversionException : ApplicationException

Also, you may want consider the following.  It is unrelated and completely a matter of
preference; however, I've read a lot about it including information straight from the
people who designed the base class libraries for .NET

Change the above class to derive from System.Exception instead of ApplicationException.

See the latter part of the post below for specific info:
http://blogs.msdn.com/brada/archive/2004/03/25/96251.aspx

Finally had some time to do some testing.  Adding [Serializable] isn't enough.  It also
requires a Serialization constructor.  The following works:

using System;
using System.Security.Permissions;
using System.Runtime.Serialization;

namespace MySql.Data.Types
{
	/// <summary>
	/// Summary description for MySqlConversionException.
	/// </summary>
    [Serializable]
	public class MySqlConversionException : ApplicationException
	{
		/// <summary>Ctor</summary>
		public MySqlConversionException(string msg)
			: base(msg)
		{
		}

        [SecurityPermission(SecurityAction.LinkDemand,
Flags=SecurityPermissionFlag.SerializationFormatter)]
        protected MySqlConversionException(SerializationInfo info, StreamingContext
context)
            : base(info, context)
        {
        }
	}
}

Hi John and thanks for your problem report. For the sake of completeness, please provide
following:
 - NET FW version
 - Small but complete test case presenting this error
 - MySQL server version

Tonci:

Sorry about that.  Here's the version info:

MySQL Server version 5.0.27-standard-log via TCP/IP
.NET version 2.0.50727

I'll come up with a short program to reproduce the error.  I think I can do it using
application domains so you won't have to mess with any remoting set issues.  I many not be
able to get to it until next week, but again the issue isn't critical.

Thanks

OK John, I'm waiting. It is realy hard to tell what's going on without proper test case
since, sometimes, one can use choose execution paths/environments not exhibiting error at
all.

Programs to recreate issue.

Attachment: bug-24957-example.txt (text/plain), 6.89 KiB.

Tonci:

I've attached a file with programs to recreate the issue.  Follow the instructions in the
file on how to split out the two programs and compile them.

The program doesn't do any database access since the issue is with the .NET exception
implementation, it just shows what happens when the MySqlConversionException is throw in a
remote object.

The issue occurs in following routine of the 2nd (the exe) program.  It should catch the
MySqlConversionException that is thrown in the remote application domain, but it doesn't.

Please let me know if you need anything else of have any questions.

Thanks

/// <summary>
/// Call the remote method and tell it to throw MySqlConversionException.
/// We should catch the MySqlConversionException, however, because it doesn't
/// handle serialization, we get a different exception.
/// </summary>
public void BugTest()
{
    Console.WriteLine(_divider);
    Console.WriteLine("     Test using MySqlConversionException");
    Console.WriteLine(_divider);
    try
    {
        // Invoke the method
        _remoteInstance.ThrowIt(false);
        Console.WriteLine("No exception occured in remote method.");
    }
    catch(MySqlConversionException cnvEx)
    {
        Console.WriteLine("MySqlConversionException occured in remote  method.  Message:
{0}", cnvEx.Message);
    }
       catch(Exception ex)
       {
          Console.WriteLine("Other occured in remote  method.  Details: {0}", ex);
       }
    }

Thanks John.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/20421

Fixed in 5.0.4 and 1.0.10

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/20422

A note has been added to the 5.0.4 and 1.0.10 changlogs.