NH-3966 - fix.

Author: fredericDelaporte

src/NHibernate/AdoNet/AbstractBatcher.cs

@@ -265,7 +265,7 @@ protected void CheckReaders()
 			}
 		}
 
-		public void CloseCommands()
+		public virtual void CloseCommands()
 		{
 			_releasing = true;
 			try

src/NHibernate/AdoNet/MySqlClientBatchingBatcher.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Data.Common;
 using System.Text;
 using NHibernate.AdoNet.Util;
@@ -97,5 +98,21 @@ private MySqlClientSqlCommandSet CreateConfiguredBatch()
 		{
 			return new MySqlClientSqlCommandSet(batchSize);
 		}
+
+		public override void CloseCommands()
+		{
+			base.CloseCommands();
+
+			try
+			{
+				currentBatch.Dispose();
+			}
+			catch (Exception e)
+			{
+				// Prevent exceptions when closing the batch from hiding any original exception
+				// (We do not know here if this batch closing occurs after a failure or not.)
+				Log.Warn("Exception closing batcher", e);
+			}
+		}
 	}
 }

src/NHibernate/AdoNet/SqlClientBatchingBatcher.cs

@@ -117,5 +117,21 @@ private SqlClientSqlCommandSet CreateConfiguredBatch()
 
 			return result;
 		}
+
+		public override void CloseCommands()
+		{
+			base.CloseCommands();
+
+			try
+			{
+				_currentBatch.Dispose();
+			}
+			catch (Exception e)
+			{
+				// Prevent exceptions when closing the batch from hiding any original exception
+				// (We do not know here if this batch closing occurs after a failure or not.)
+				Log.Warn("Exception closing batcher", e);
+			}
+		}
 	}
 }