2008-06-13 Atsushi Enomoto <atsushi@ximian.com>

2008-06-13  Atsushi Enomoto  <atsushi@ximian.com>

	* DataColumn.cs
	  DefaultValue can be non-DBNull. For SqlXxx type, it becomes
	  SqlXxx.Null. Also, changing DataType may change DefaultValue
	  to be consistent with the new type (say, having int DefaultValue
	  for new string DataType is wrong).

	* XmlSchemaWriter.cs
	  This should be fixed to take non-DBNull default value into
	  consideration.

	* DataTableTest.cs, DataSetTest.cs
	  We could use default value as is, not in string form. This makes
	  comparison more strict.

	* DataColumnTest.cs
	  Added test for non-DBNull case and changing DataType case.

svn path=/trunk/mcs/; revision=105753