Changed the PetaPocoUnitOfWorkProvider to ensure that a new Database object is used for each new

unit of work (transaction). When the UOW is diposed, the database instance will also be disposed.

src/Umbraco.Core/Persistence/UnitOfWork/PetaPocoUnitOfWork.cs

@@ -20,6 +20,14 @@ namespace Umbraco.Core.Persistence.UnitOfWork
         private readonly List<Operation> _operations = new List<Operation>();
 
 
+		/// <summary>
+		/// Creates a new unit of work instance
+		/// </summary>
+		/// <param name="database"></param>
+		/// <remarks>
+		/// The Database instance used for this unit of work should not be shared with other unit's of work, other repositories, etc...
+		/// as it will get disposed of when this unit of work is disposed.
+		/// </remarks>
 		public PetaPocoUnitOfWork(UmbracoDatabase database)
         {
 	        Database = database;
@@ -151,16 +159,15 @@ namespace Umbraco.Core.Persistence.UnitOfWork
 
 		/// <summary>
 		/// Ensures disposable objects are disposed
-		/// </summary>
+		/// </summary>		
 		/// <remarks>
-		/// We will not dispose the database because this will get disposed of automatically when 
-		/// in the HttpContext by the UmbracoModule because the DatabaseFactory stores the instance in HttpContext.Items 
-		/// when in a web context.
-		/// When not in a web context, we may possibly be re-using the database context.
+		/// Ensures that the Database instance is disposed of. As per the constructor documentation, the database instance
+		/// used to construct this object should not be shared as it will get disposed of when this object is disposed.
 		/// </remarks>
 	    protected override void DisposeResources()
 	    {
 			_operations.Clear();			
+			Database.Dispose();
 	    }
     }
 }

src/Umbraco.Core/Persistence/UnitOfWork/PetaPocoUnitOfWorkProvider.cs

@@ -13,9 +13,20 @@ namespace Umbraco.Core.Persistence.UnitOfWork
 	    
 	    #region Implementation of IUnitOfWorkProvider
 
+		/// <summary>
+		/// Creates a Unit of work with a new UmbracoDatabase instance for the work item/transaction.
+		/// </summary>
+		/// <returns></returns>
+		/// <remarks>
+		/// Each PetaPoco UOW uses it's own Database object, not the shared Database object that comes from
+		/// the DatabaseContext.Current.Database. This is because each transaction should use it's own Database
+		/// and we Dispose of this Database object when the UOW is disposed.
+		/// </remarks>
 	    public IDatabaseUnitOfWork GetUnitOfWork()
         {
-			return new PetaPocoUnitOfWork(DatabaseContext.Current.Database);
+			return new PetaPocoUnitOfWork(
+				new UmbracoDatabase(
+					GlobalSettings.UmbracoConnectionName));
         }
 
         #endregion