Fix dependent association joins

Author: maca88

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

@@ -946,5 +946,30 @@ private void AssertDuplicateEntitySelectionSubQuery(string sql, IList result, bo
 		}
 
 		#endregion
+
+		#region DependentEntityJoin
+
+		[Test]
+		public async Task HqlDependentEntityJoinAsync()
+		{
+			await (AssertDependentEntityJoinAsync(@"from Order o 
+inner join (from Order where OrderId = :id) o2 on (o.OrderId - 1) = o2.OrderId 
+left join o.Employee e on e = o2.Employee"));
+		}
+
+		private async Task AssertDependentEntityJoinAsync(string query, CancellationToken cancellationToken = default(CancellationToken))
+		{
+			var result = await (session.CreateQuery(query).SetParameter("id", 10248).ListAsync(cancellationToken));
+			Assert.That(result, Has.Count.EqualTo(1));
+			var item = result[0];
+			Assert.That(item, Is.TypeOf<object[]>());
+			var array = (object[]) item;
+			Assert.That(array, Has.Length.EqualTo(3));
+			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[2], Is.Null);
+		}
+
+		#endregion
 	}
 }

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

@@ -934,5 +934,30 @@ private void AssertDuplicateEntitySelectionSubQuery(string sql, IList result, bo
 		}
 
 		#endregion
+
+		#region DependentEntityJoin
+
+		[Test]
+		public void HqlDependentEntityJoin()
+		{
+			AssertDependentEntityJoin(@"from Order o 
+inner join (from Order where OrderId = :id) o2 on (o.OrderId - 1) = o2.OrderId 
+left join o.Employee e on e = o2.Employee");
+		}
+
+		private void AssertDependentEntityJoin(string query)
+		{
+			var result = session.CreateQuery(query).SetParameter("id", 10248).List();
+			Assert.That(result, Has.Count.EqualTo(1));
+			var item = result[0];
+			Assert.That(item, Is.TypeOf<object[]>());
+			var array = (object[]) item;
+			Assert.That(array, Has.Length.EqualTo(3));
+			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[2], Is.Null);
+		}
+
+		#endregion
 	}
 }

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

@@ -1320,6 +1320,7 @@ private void HandleWithFragment(FromElement fromElement, IASTNode hqlWithNode)
 				sql.whereExpr();
 
 				fromElement.WithClauseFragment = new SqlString("(", sql.GetSQL(), ")");
+				fromElement.WithClauseFromElements = visitor.FromElements;
 			}
 			catch (SemanticException)
 			{
@@ -1345,6 +1346,8 @@ public WithClauseVisitor(FromElement fromElement)
 			_joinFragment = fromElement;
 		}
 
+		internal HashSet<FromElement> FromElements { get; } = new HashSet<FromElement>();
+
 		public void Visit(IASTNode node)
 		{
 			if (node is ParameterNode paramNode)
@@ -1355,6 +1358,10 @@ public void Visit(IASTNode node)
 			{
 				ApplyParameterSpecifications(paramContainer);
 			}
+			else if (node is ISelectExpression selectExpression && selectExpression.FromElement != null)
+			{
+				FromElements.Add(selectExpression.FromElement);
+			}
 		}
 
 		private void ApplyParameterSpecifications(IParameterContainer parameterContainer) 

src/NHibernate/Hql/Ast/ANTLR/SqlGenerator.g

@@ -195,6 +195,8 @@ fromTable
 tableJoin [ IASTNode parent ]
 	: ^( c=JOIN_FRAGMENT { Out(" "); Out($c); } (tableJoin [ c ] )* )
 	| ^( d=FROM_FRAGMENT { NestedFromFragment($d,parent); } (tableJoin [ d ] )* )
+	| ^( e=ENTITY_JOIN   { Out(" "); Out(e); } (tableJoin [ e ])* )
+	| ^( f=JOIN_SUBQUERY { Out(" "); StartJoinSubquery(); } selectStatement { EndJoinSubquery(f); } (tableJoin [ f ])* )
 	;
 
 booleanOp[ bool parens ]

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

@@ -436,9 +436,36 @@ internal void FinishInit()
 		{
 			foreach (var item in _appendFromElements)
 			{
-				AddChild(item);
+				var dependentElement = GetFirstDependentFromElement(item);
+				if (dependentElement == null)
+				{
+					AddChild(item);
+				}
+				else
+				{
+					var index = dependentElement.ChildIndex;
+					dependentElement.Parent.InsertChild(index, item);
+				}
 			}
 			_appendFromElements.Clear();
 		}
+
+		private FromElement GetFirstDependentFromElement(FromElement element)
+		{
+			foreach (var fromElement in _fromElements)
+			{
+				if (fromElement == element ||
+					fromElement.WithClauseFromElements?.Contains(element) != true ||
+				    // Parent will be null for entity and subquery joins
+				    fromElement.Parent == null)
+				{
+					continue;
+				}
+
+				return fromElement;
+			}
+
+			return null;
+		}
 	}
 }

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

@@ -330,6 +330,8 @@ public SqlString WithClauseFragment
 			set { _withClauseFragment = value; }
 		}
 
+		internal HashSet<FromElement> WithClauseFromElements { get; set; }
+
 		// Since 5.4
 		[Obsolete("This method has no more usages and will be removed in a future version.")]
 		public string WithClauseJoinAlias