Fix broken tests

Author: maca88

src/NHibernate.Test/Linq/ByMethod/JoinSubqueryTests.cs

@@ -1,4 +1,5 @@
 using System.Collections;
+using System.Linq;
 using NHibernate.DomainModel.Northwind.Entities;
 using NUnit.Framework;
 using NUnit.Framework.Constraints;
@@ -745,7 +746,7 @@ inner join fetch o1.OrderLines
 	select o, o2.ord
 	from Order o
 	inner join (
-		select o1 as ord, o1.OrderLines.size
+		select o1 as ord, o1.ShippedTo
 		from Order o1
 		inner join fetch o1.OrderLines
 		where o1.OrderId = 10248
@@ -810,7 +811,7 @@ inner join fetch o1.ProductIds
 	select o, o2.ord
 	from Order o
 	inner join (
-		select o1 as ord, o1.OrderLines.size
+		select o1 as ord, o1.ShippedTo
 		from Order o1
 		inner join fetch o1.ProductIds
 		where o1.OrderId = 10248
@@ -854,5 +855,86 @@ private void AssertEntitySubQueryWithCollectionOfValuesFetch(IList result, bool[
 		}
 
 		#endregion
+
+		#region HqlDuplicateEntitySelectionSubQuery
+
+		[Test]
+		public void HqlDuplicateEntitySelectionSubQuery()
+		{
+			AssertDuplicateEntitySelectionSubQuery(@"
+	from Order o
+	inner join (
+		select o1 as ord1, o1 as ord2
+		from Order o1
+		where o1.OrderId = 10248
+	) o2 on (o.OrderId - 1) = o2.ord1.OrderId");
+
+			AssertDuplicateEntitySelectionSubQuery(@"
+	select o, o2.ord1, o2.ord2
+	from Order o
+	inner join (
+		select o1 as ord1, o1 as ord2
+		from Order o1
+		where o1.OrderId = 10248
+	) o2 on (o.OrderId - 1) = o2.ord1.OrderId");
+
+			AssertDuplicateEntitySelectionSubQuery(@"
+	select o, o2, o2
+	from Order o
+	inner join (
+		select o1
+		from Order o1
+		where o1.OrderId = 10248
+	) o2 on (o.OrderId - 1) = o2.OrderId");
+
+			AssertDuplicateEntitySelectionSubQuery(@"
+	select o, o2, o2
+	from Order o
+	inner join (
+		from Order
+		where OrderId = 10248
+	) o2 on (o.OrderId - 1) = o2.OrderId");
+		}
+
+		private void AssertDuplicateEntitySelectionSubQuery(string query)
+		{
+			IList result;
+			using (var logSpy = new SqlLogSpy())
+			{
+				result = session.CreateQuery(query).List();
+				AssertDuplicateEntitySelectionSubQuery(logSpy.GetWholeLog(), result, false);
+			}
+
+			using (var logSpy = new SqlLogSpy())
+			{
+				result = session.CreateQuery(query).Enumerable().OfType<object[]>().ToList();
+				AssertDuplicateEntitySelectionSubQuery(logSpy.GetWholeLog(), result, true);
+			}
+		}
+
+		private void AssertDuplicateEntitySelectionSubQuery(string sql, IList result, bool shallow)
+		{
+			var selectSql = sql.Substring(0, sql.IndexOf("from"));
+			var item = result[0];
+			Assert.That(item, Is.TypeOf<object[]>());
+			var array = (object[]) item;
+			Assert.That(array, Has.Length.EqualTo(3));
+			if (shallow)
+			{
+				Assert.That(GetTotalOccurrences(selectSql, ","), Is.EqualTo(1));
+				Assert.That(array[0], Is.AssignableFrom<Order>().And.Property("OrderId").EqualTo(10249));
+				Assert.That(array[1], Is.AssignableFrom<Order>().And.Property("OrderId").EqualTo(10248));
+				Assert.That(array[1], Is.AssignableFrom<Order>().And.Property("OrderId").EqualTo(10248));
+			}
+			else
+			{
+				Assert.That(GetTotalOccurrences(selectSql, ","), Is.EqualTo(27));
+				Assert.That(array[0], Is.TypeOf<Order>().And.Property("OrderId").EqualTo(10249));
+				Assert.That(array[1], Is.TypeOf<Order>().And.Property("OrderId").EqualTo(10248));
+				Assert.That(array[1], Is.TypeOf<Order>().And.Property("OrderId").EqualTo(10248));
+			}
+		}
+
+		#endregion
 	}
 }

src/NHibernate/Hql/Ast/ANTLR/HqlSqlWalker.cs

@@ -1237,7 +1237,7 @@ public bool IsShallowQuery
 			get 
 			{
 				// select clauses for insert statements should alwasy be treated as shallow
-				return StatementType == INSERT ||  _qti.IsShallowQuery;
+				return StatementType == INSERT || (_qti.IsShallowQuery && !_currentFromClause.IsJoinSubQuery);
 			}
 		}
 

src/NHibernate/Hql/Ast/ANTLR/Tree/SelectClause.cs

@@ -103,9 +103,7 @@ public void InitializeExplicitSelectClause(FromClause fromClause)
 			var inheritedExpressions = new Dictionary<ISelectExpression, SelectClause>();
 			SelectExpressions = GetSelectExpressions();
 			OriginalSelectExpressions = SelectExpressions.ToList();
-			NonScalarExpressions = !Walker.IsShallowQuery
-				? new List<ISelectExpression>()
-				: null;
+			NonScalarExpressions = new List<ISelectExpression>();
 			var length = SelectExpressions.Count;
 			for (var i = 0; i < length; i++)
 			{
@@ -152,7 +150,7 @@ public void InitializeExplicitSelectClause(FromClause fromClause)
 
 						if (!selectClause.IsScalarSelect)
 						{
-							RemoveChild((IASTNode) expr);
+							RemoveChildAndUnsetParent((IASTNode) expr);
 						}
 
 						subqueryExpressions = new List<ISelectExpression>();
@@ -180,7 +178,7 @@ public void InitializeExplicitSelectClause(FromClause fromClause)
 					var indexes = new List<int>(subqueryExpressions.Count);
 					foreach (var expression in subqueryExpressions)
 					{
-						inheritedExpressions.Add(expression, selectClause);
+						inheritedExpressions[expression] = selectClause;
 						indexes.Add(i);
 						SelectExpressions.Insert(i, expression);
 						i++;
@@ -227,16 +225,21 @@ private void Render(
 				InitializeScalarColumnNames();
 			}
 
+			// generate id select fragment and then property select fragment for
+			// each expression, just like generateSelectFragments().
+			RenderNonScalarSelects(fromClause, inheritedExpressions, GetFetchedFromElements(fromClause));
+		}
+
+		private List<FromElement> GetFetchedFromElements(FromClause fromClause)
+		{
+			var fetchedFromElements = new List<FromElement>();
 			if (Walker.IsShallowQuery)
 			{
-				RenderDerivedNonScalarIdentifiers(fromClause);
-				return;
+				return fetchedFromElements;
 			}
 
-			var fetchedFromElements = new List<FromElement>();
 			// add the fetched entities
-			var fromElements = fromClause.GetAllProjectionListTyped();
-			foreach (FromElement fromElement in fromElements)
+			foreach (FromElement fromElement in fromClause.GetAllProjectionListTyped())
 			{
 				if (!fromElement.IsFetch)
 				{
@@ -278,9 +281,7 @@ private void Render(
 				}
 			}
 
-			// generate id select fragment and then property select fragment for
-			// each expression, just like generateSelectFragments().
-			RenderNonScalarSelects(fromClause, inheritedExpressions, fetchedFromElements);
+			return fetchedFromElements;
 		}
 
 		private void AddExpression(ISelectExpression expr, List<IType> queryReturnTypeList)
@@ -452,19 +453,40 @@ private void RenderNonScalarSelects(
 		{
 			var appender = new ASTAppender(ASTFactory, this);
 			var combinedFromElements = new List<FromElement>();
+			var processedElements = new HashSet<FromElement>();
 			foreach (var e in NonScalarExpressions)
 			{
 				var fromElement = e.FromElement;
-				if (fromElement != null)
+				if (fromElement == null)
+				{
+					continue;
+				}
+
+				var node = (IASTNode) e;
+				if (processedElements.Add(fromElement))
 				{
 					combinedFromElements.Add(fromElement);
 					RenderNonScalarIdentifiers(fromElement, inheritedExpressions.ContainsKey(e) ? null : e, appender);
 				}
+				else if (!inheritedExpressions.ContainsKey(e) && node.Parent != null)
+				{
+					RemoveChildAndUnsetParent(node);
+				}
+			}
+
+			if (Walker.IsShallowQuery)
+			{
+				return;
 			}
 
 			// Append fetched elements
 			foreach (var fetchedFromElement in fetchedFromElements)
 			{
+				if (!processedElements.Add(fetchedFromElement))
+				{
+					continue;
+				}
+
 				fetchedFromElement.EntitySuffix = Walker.GetEntitySuffix(fetchedFromElement);
 				combinedFromElements.Add(fetchedFromElement);
 				var fragment = fetchedFromElement.GetIdentifierSelectFragment(fetchedFromElement.EntitySuffix);
@@ -495,7 +517,9 @@ private void RenderNonScalarSelects(
 			var fromElements = currentFromClause.GetAllProjectionListTyped();
 			foreach (var fromElement in fromElements)
 			{
-				if (fromElement.IsCollectionOfValuesOrComponents && fromElement.IsFetch)
+				if (fromElement.IsCollectionOfValuesOrComponents &&
+					fromElement.IsFetch &&
+					processedElements.Add(fromElement))
 				{
 					var suffix = Walker.GetSuffix(fromElement);
 					var fragment = fromElement.GetValueCollectionSelectFragment(suffix);
@@ -514,25 +538,16 @@ private IASTNode Append(ASTAppender appender, int type, SelectFragment fragment)
 			return appender.Append(type, fragment.ToSqlStringFragment(false), false);
 		}
 
-		private void RenderDerivedNonScalarIdentifiers(FromClause fromClause)
+		private void RenderNonScalarIdentifiers(FromElement fromElement, ISelectExpression expr, ASTAppender appender)
 		{
-			// Render only when scalar columns are not rendered
-			if (_derivedSelectExpressions == null || !fromClause.IsScalarSubQuery)
+			if (fromElement.FromClause.IsScalarSubQuery && _derivedSelectExpressions?.Contains(expr) != true)
 			{
 				return;
 			}
 
-			var appender = new ASTAppender(ASTFactory, this);
-			foreach (var derivedSelectExpression in _derivedSelectExpressions)
-			{
-				RenderNonScalarIdentifiers(derivedSelectExpression.FromElement, derivedSelectExpression, appender);
-			}
-		}
-
-		private void RenderNonScalarIdentifiers(FromElement fromElement, ISelectExpression expr, ASTAppender appender)
-		{
-			if (fromElement.FromClause.IsScalarSubQuery && _derivedSelectExpressions?.Contains(expr) != true)
+			if (Walker.IsShallowQuery && !fromElement.FromClause.IsScalarSubQuery && SelectExpressions.Contains(expr))
 			{
+				// A scalar column was generated
 				return;
 			}
 
@@ -541,8 +556,7 @@ private void RenderNonScalarIdentifiers(FromElement fromElement, ISelectExpressi
 			if (fragment == null)
 			{
 				// When a subquery join has a scalar select only
-				var node = (IASTNode) expr;
-				node?.Parent.RemoveChild(node);
+				RemoveChildAndUnsetParent((IASTNode) expr);
 				return;
 			}
 
@@ -706,5 +720,14 @@ public int GetColumnNamesStartPosition(int i)
 		{
 			return _columnNamesStartPositions[i];
 		}
+
+		private static void RemoveChildAndUnsetParent(IASTNode node)
+		{
+			if (node?.Parent != null)
+			{
+				node.Parent.RemoveChild(node);
+				node.Parent = null;
+			}
+		}
 	}
 }

src/NHibernate/Persister/Entity/SubqueryPropertyMapping.cs

@@ -73,6 +73,11 @@ public SubqueryPropertyMapping(IType type, SelectClause selectClause)
 				}
 				else
 				{
+					if (_propertyMappings.ContainsKey(mapping))
+					{
+						throw new QueryException($"Subquery selects the same type '{mapping.Type}' multiple times. Use unique alias for each type selection.");
+					}
+
 					_propertyMappings.Add(mapping, fromElement.EntitySuffix ?? fromElement.CollectionSuffix);
 				}
 			}
@@ -189,15 +194,17 @@ public string[] ToColumns(string alias, string propertyName)
 		public List<string> GetPropertiesColumns(string alias)
 		{
 			var columns = new List<string>();
+			var processedElements = new HashSet<FromElement>();
 			foreach (var expression in _selectClause.NonScalarExpressions)
 			{
-				if (expression.FromElement == null || expression.FromElement.IsFetch)
+				var fromElement = expression.FromElement;
+				if (fromElement == null || fromElement.IsFetch || !processedElements.Add(fromElement))
 				{
 					continue;
 				}
 
-				var fragment = expression.FromElement.GetPropertiesSelectFragment(expression.FromElement.EntitySuffix, alias);
-				if (expression.FromElement is JoinSubqueryFromElement)
+				var fragment = fromElement.GetPropertiesSelectFragment(fromElement.EntitySuffix, alias);
+				if (fromElement is JoinSubqueryFromElement)
 				{
 					columns.AddRange(fragment.GetColumnAliases());
 				}
@@ -221,20 +228,25 @@ public List<string> GetPropertiesColumns(string alias)
 		public List<string> GetIdentifiersColumns(string alias)
 		{
 			var columns = new List<string>();
+			var processedElements = new HashSet<FromElement>();
 			foreach (var expression in _selectClause.NonScalarExpressions)
 			{
-				if (expression.FromElement == null || expression.FromElement.FromClause.IsScalarSubQuery || expression.FromElement.IsFetch)
+				var fromElement = expression.FromElement;
+				if (fromElement == null ||
+				    fromElement.FromClause.IsScalarSubQuery ||
+				    fromElement.IsFetch ||
+				    !processedElements.Add(fromElement))
 				{
 					continue;
 				}
 
-				var fragment = expression.FromElement.GetIdentifierSelectFragment(expression.FromElement.EntitySuffix, alias);
+				var fragment = fromElement.GetIdentifierSelectFragment(fromElement.EntitySuffix, alias);
 				if (fragment == null)
 				{
 					continue; // Subquery with scalar select
 				}
 
-				if (expression.FromElement is JoinSubqueryFromElement)
+				if (fromElement is JoinSubqueryFromElement)
 				{
 					columns.AddRange(fragment.GetColumnAliases());
 				}