QueryLock: Add test case to verify that a change in lock mode will avoid reusing cached query.

Author: oskarb

src/NHibernate.Test/Linq/QueryLock.cs

@@ -1,5 +1,6 @@
 using System.Linq;
 using System.Transactions;
+using NHibernate.Dialect;
 using NHibernate.DomainModel.Northwind.Entities;
 using NHibernate.Exceptions;
 using NHibernate.Linq;
@@ -76,6 +77,36 @@ private void AssertSeparateTransactionIsLockedOut(string customerId)
 					}, "Expected an exception to indicate locking failure due to already locked.");
 			}
 		}
+
+
+		[Test]
+		[Description("Verify that different lock modes are respected even if the query is otherwise exactly the same.")]
+		public void CanChangeLockModeForQuery()
+		{
+			// Limit to a few dialects where we know the "nowait" keyword is used to make life easier.
+			Assume.That(Dialect is MsSql2000Dialect || Dialect is Oracle8iDialect || Dialect is PostgreSQL81Dialect);
+
+			using (session.BeginTransaction())
+			{
+				var result = BuildQueryableAllCustomers(db.Customers, LockMode.Upgrade).ToList();
+				Assert.That(result, Has.Count.EqualTo(91));
+
+				using (var logSpy = new SqlLogSpy())
+				{
+					// Only difference in query is the lockmode - make sure it gets picked up.
+					var result2 = BuildQueryableAllCustomers(session.Query<Customer>(), LockMode.UpgradeNoWait).ToList();
+					Assert.That(result2, Has.Count.EqualTo(91));
+
+					Assert.That(logSpy.GetWholeLog().ToLower(), Is.StringContaining("nowait"));
+				}
+			}
+		}
+
+		private static IQueryable<Customer> BuildQueryableAllCustomers(IQueryable<Customer> dbCustomers, LockMode lockMode)
+		{
+			return (from e in dbCustomers
+			        select e).SetLockMode(lockMode).Timeout(5);
+		}
 	}
 }