Implementation (fix) NH-3427

Joining to association twice using criteria.

Author: gmalyshev

src/NHibernate.Test/NHSpecificTest/NH3472/Domain.cs

@@ -0,0 +1,27 @@
+using System.Collections;
+using System.Collections.Generic;
+
+namespace NHibernate.Test.NHSpecificTest.NH3472
+{
+
+	public class Cat
+	{
+		private int id;
+		private IList<Cat> children = new List<Cat>();
+
+		public virtual string Color { get; set; }
+		public int Age { get; set; }
+
+		public int Id
+		{
+			get { return id; }
+			set { id = value; }
+		}
+
+		public IList<Cat> Children
+		{
+			get { return children; }
+			set { children = value; }
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/NH3472/Fixture.cs

@@ -0,0 +1,58 @@
+using System.Collections.Generic;
+using NHibernate.Criterion;
+using NHibernate.SqlCommand;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.NH3472
+{
+	[TestFixture]
+	public class Fixture : BugTestCase
+	{
+		[Test]
+		public void CriteriaQueryWithMultipleJoinsToSameAssociation()
+		{
+			using (ISession sess = OpenSession())
+			{
+				Cat c = new Cat();
+				c.Age = 0;
+				c.Children = new List<Cat>
+				{
+					new Cat {Color = "Ginger", Age = 1},
+					new Cat {Color = "Black", Age = 3}
+				};
+				sess.Save(c);
+				sess.Flush();
+			}
+
+			using (ISession sess = OpenSession())
+			{
+				try
+				{
+					var list = sess.CreateCriteria<Cat>("cat")
+						.CreateAlias("cat.Children", "gingerCat", JoinType.LeftOuterJoin, Restrictions.Eq("Color", "Ginger"))
+
+						.CreateAlias("cat.Children", "blackCat", JoinType.LeftOuterJoin,
+							Restrictions.Eq("Color", "Black"))
+						.SetProjection(
+							Projections.Alias(Projections.Property("gingerCat.Age"), "gingerCatAge"),
+							Projections.Alias(Projections.Property("blackCat.Age"), "blackCatAge")
+						).AddOrder(new Order(Projections.Property("Age"), true)).List<object[]>();
+					Assert.AreEqual(list.Count, 3);
+					Assert.AreEqual(list[0][0], 1);
+					Assert.AreEqual(list[0][1], 3);
+
+					Assert.IsNull(list[1][0]);
+					Assert.IsNull(list[1][1]);
+
+					Assert.IsNull(list[2][0]);
+					Assert.IsNull(list[2][1]);
+				}
+				finally
+				{
+					sess.Delete("from Cat");
+					sess.Flush();
+				}
+			}
+		}
+	}
+}

src/NHibernate.Test/NHSpecificTest/NH3472/Mappings.hbm.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8" ?> 
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
+	assembly="NHibernate.Test"
+	namespace="NHibernate.Test.NHSpecificTest.NH3472"
+	default-lazy="false">
+
+  <class name="Cat">
+    <id name="Id" type="Int32"  unsaved-value="0" >
+      <generator class="native" />
+    </id>
+
+    <property name="Color" type="string"/>
+    <property name="Age" type="int"/>
+
+    <bag name="Children" cascade="all" lazy="true">
+      <key column="parentId" />
+      <one-to-many class="Cat"  />
+    </bag>
+  </class>
+
+  
+
+</hibernate-mapping>

src/NHibernate/Loader/Criteria/CriteriaJoinWalker.cs

@@ -80,7 +80,7 @@ protected override void AddAssociations()
 			foreach (var entityJoinInfo in translator.GetEntityJoins().Values)
 			{
 				var tableAlias = translator.GetSQLAlias(entityJoinInfo.Criteria);
-				var criteriaPath = entityJoinInfo.Criteria.Alias; //path for entity join is equal to alias
+				var criteriaPath = entityJoinInfo.Criteria.Alias;
 				var persister = entityJoinInfo.Persister as IOuterJoinLoadable;
 				AddExplicitEntityJoinAssociation(persister, tableAlias, translator.GetJoinType(criteriaPath), criteriaPath);
 				IncludeInResultIfNeeded(persister, entityJoinInfo.Criteria, tableAlias, criteriaPath);
@@ -166,13 +166,20 @@ public override string Comment
 			get { return "criteria query"; }
 		}
 
-		protected override JoinType GetJoinType(IAssociationType type, FetchMode config, string path, string lhsTable,
-		                                        string[] lhsColumns, bool nullable, int currentDepth,
-		                                        CascadeStyle cascadeStyle)
+		protected override IList<string> AliasByPath(string path, string sqlAlias)
 		{
-			if (translator.IsJoin(path))
+			var alias = translator.AliasByPath(path, sqlAlias);
+			if (alias.Count == 0)
+				return base.AliasByPath(path, sqlAlias);
+			return alias;
+		}
+
+		protected override JoinType GetJoinType(IAssociationType type, FetchMode config, string path, string pathAlias,
+			string lhsTable, string[] lhsColumns, bool nullable, int currentDepth, CascadeStyle cascadeStyle)
+		{
+			if (translator.IsJoin(path, pathAlias))
 			{
-				return translator.GetJoinType(path);
+				return translator.GetJoinType(path, pathAlias);
 			}
 
 			if (translator.HasProjection)
@@ -184,7 +191,7 @@ protected override JoinType GetJoinType(IAssociationType type, FetchMode config,
 			switch (selectMode)
 			{
 				case SelectMode.Undefined:
-					return base.GetJoinType(type, config, path, lhsTable, lhsColumns, nullable, currentDepth, cascadeStyle);
+					return base.GetJoinType(type, config, path, pathAlias, lhsTable, lhsColumns, nullable, currentDepth, cascadeStyle);
 
 				case SelectMode.Fetch:
 				case SelectMode.FetchLazyProperties:
@@ -200,7 +207,7 @@ protected override JoinType GetJoinType(IAssociationType type, FetchMode config,
 			}
 		}
 
-		protected override string GenerateTableAlias(int n, string path, IJoinable joinable)
+		protected override string GenerateTableAlias(int n, string path, string pathAlias, IJoinable joinable)
 		{
 			// TODO: deal with side-effects (changes to includeInSelectList, userAliasList, resultTypeList)!!!
 
@@ -225,14 +232,14 @@ protected override string GenerateTableAlias(int n, string path, IJoinable joina
 
 			if (shouldCreateUserAlias)
 			{
-				ICriteria subcriteria = translator.GetCriteria(path);
+				ICriteria subcriteria = translator.GetCriteria(path, pathAlias);
 				sqlAlias = subcriteria == null ? null : translator.GetSQLAlias(subcriteria);
 
 				IncludeInResultIfNeeded(joinable, subcriteria, sqlAlias, path);
 			}
 
 			if (sqlAlias == null)
-				sqlAlias = base.GenerateTableAlias(n + translator.SQLAliasCount, path, joinable);
+				sqlAlias = base.GenerateTableAlias(n + translator.SQLAliasCount, path, pathAlias, joinable);
 
 			return sqlAlias;
 		}
@@ -261,9 +268,9 @@ protected override string GenerateRootAlias(string tableName)
 			// NH: really not used (we are using a different ctor to support SubQueryCriteria)
 		}
 
-		protected override SqlString GetWithClause(string path)
+		protected override SqlString GetWithClause(string path, string pathAlias)
 		{
-			return translator.GetWithClause(path);
+			return translator.GetWithClause(path, pathAlias);
 		}
 	}
 }