NH-3889 - Fixed weird extra joins in subqueries

src/NHibernate.Test/NHSpecificTest/NH3889/Entity.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+
+namespace NHibernate.Test.NHSpecificTest.NH3889
+{
+	public class TimeRecord
+	{
+		public virtual Guid Id { get; set; }
+		public virtual Project Project { get; set; }
+		public virtual Job ActualJob { get; set; }
+		public virtual decimal Hours { get; set; }
+
+		public virtual TimeSetting Setting { get; set; }
+	}
+
+	public class TimeSetting
+	{
+		public virtual Guid Id { get; set; }
+		public virtual TimeInclude Include { get; set; }
+	}
+
+	public class TimeInclude
+	{
+		public virtual Guid Id { get; set; }
+		public virtual bool Flag { get; set; }
+	}
+
+	public class Project
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; }
+		public virtual Job Job { get; set; }
+	}
+
+	public class Job
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; }
+	}
+}

src/NHibernate.Test/NHSpecificTest/NH3889/FixtureByCode.cs

@@ -0,0 +1,265 @@
+using System;
+using System.Linq;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Dialect;
+using NHibernate.Linq;
+using NHibernate.Mapping.ByCode;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.NH3889
+{
+	public class ByCodeFixture : TestCaseMappingByCode
+	{
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+			mapper.Class<Job>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+			});
+			mapper.Class<Project>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+				rc.ManyToOne(x => x.Job, map =>
+				{
+					map.Column("JobId");
+					map.NotNullable(true);
+				});
+			});
+			mapper.Class<TimeRecord>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Hours);
+				rc.ManyToOne(x => x.Project, map =>
+				{
+					map.Column("ProjectId");
+					map.NotNullable(true);
+				});
+				rc.ManyToOne(x => x.ActualJob, map =>
+				{
+					map.Column("ActualJobId");
+				});
+				rc.ManyToOne(x => x.Setting, map =>
+				{
+					map.Column("SettingId");
+				});
+			});
+
+			mapper.Class<TimeSetting>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.ManyToOne(x => x.Include, map =>
+				{
+					map.Column("IncludeId");
+				});
+			});
+
+			mapper.Class<TimeInclude>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Flag);
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var job_a = new Job { Name = "Big Job" };
+				session.Save(job_a);
+				var job_b = new Job { Name = "Small Job" };
+				session.Save(job_b);
+
+				var project_a = new Project { Job = job_a, Name = "Big Job - Part A" };
+				session.Save(project_a);
+				var project_b = new Project { Job = job_a, Name = "Big Job - Part B" };
+				session.Save(project_b);
+				var project_c = new Project { Job = job_b, Name = "Small Job - Rework" };
+				session.Save(project_c);
+
+				var include = new TimeInclude { Flag = true };
+				session.Save(include);
+				var setting = new TimeSetting { Include = include };
+				session.Save(setting);
+
+				session.Save(new TimeRecord {Project = project_a, Hours = 2, Setting = setting }/*.AddTime(2)*/);
+				session.Save(new TimeRecord {Project = project_a, Hours = 3, Setting = setting }/*.AddTime(3)*/);
+				session.Save(new TimeRecord {Project = project_b, Hours = 5, Setting = setting }/*.AddTime(2).AddTime(3)*/);
+				session.Save(new TimeRecord {Project = project_b, Hours = 2, Setting = setting }/*.AddTime(1).AddTime(1)*/);
+				session.Save(new TimeRecord {Project = project_c, Hours = 7, Setting = setting }/*.AddTime(2).AddTime(3).AddTime(2)*/);
+				session.Save(new TimeRecord {Project = project_c, ActualJob = job_a, Hours = 3, Setting = setting }/*.AddTime(1).AddTime(1).AddTime(1)*/);
+
+				session.Flush();
+				transaction.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				session.Delete("from TimeRecord");
+				session.Delete("from TimeInclude");
+				session.Delete("from TimeSetting");
+				session.Delete("from Project");
+				session.Delete("from Job");
+
+				session.Flush();
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		public void CoalesceOnEntitySum()
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var job_a = session.Query<Job>().Single(j => j.Name == "Big Job");
+				var job_a_hours = session.Query<TimeRecord>()
+					.Where(t => (t.ActualJob ?? t.Project.Job) == job_a)
+					.Sum(t => t.Hours);
+				Assert.That(job_a_hours, Is.EqualTo(15));
+
+				var job_b = session.Query<Job>().Single(j => j.Name == "Small Job");
+				var job_b_hours = session.Query<TimeRecord>()
+					.Where(t => (t.ActualJob ?? t.Project.Job) == job_b)
+					.Sum(t => t.Hours);
+				Assert.That(job_b_hours, Is.EqualTo(7));
+			}
+		}
+
+		[Test]
+		public void CoalesceOnEntitySumWithExtraJoin()
+		{
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var include = session.Query<TimeInclude>().Single();
+
+				var job_a = session.Query<Job>().Single(j => j.Name == "Big Job");
+				var job_a_hours = session.Query<TimeRecord>()
+					.Where(t => (t.ActualJob ?? t.Project.Job) == job_a)
+					.Where(t => t.Setting.Include == include)
+					.Sum(t => t.Hours);
+				Assert.That(job_a_hours, Is.EqualTo(15));
+
+				var job_b = session.Query<Job>().Single(j => j.Name == "Small Job");
+				var job_b_hours = session.Query<TimeRecord>()
+					.Where(t => (t.ActualJob ?? t.Project.Job) == job_b)
+					.Where(t => t.Setting.Include == include)
+					.Sum(t => t.Hours);
+				Assert.That(job_b_hours, Is.EqualTo(7));
+			}
+		}
+
+		[Test]
+		public void CoalesceOnEntitySubselectSum()
+		{
+			AssertDialect();
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var query = session.Query<Job>()
+								.Select(j => new
+								{
+									Job = j,
+									Hours = session.Query<TimeRecord>()
+												.Where(t => (t.ActualJob ?? t.Project.Job) == j)
+												.Sum(t => (decimal?)t.Hours) ?? 0
+								});
+				var results = query.ToList();
+
+				Assert.That(results.Count, Is.EqualTo(2));
+				Assert.That(results.Single(x => x.Job.Name == "Big Job").Hours, Is.EqualTo(15));
+				Assert.That(results.Single(x => x.Job.Name == "Small Job").Hours, Is.EqualTo(7));
+			}
+		}
+
+		[Test]
+		public void CoalesceOnEntitySubselectSumWithExtraJoin()
+		{
+			AssertDialect();
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var include = session.Query<TimeInclude>().Single();
+
+				var query = session.Query<Job>()
+								.Select(j => new
+								{
+									Job = j,
+									Hours = session.Query<TimeRecord>()
+												.Where(t => (t.ActualJob ?? t.Project.Job) == j)
+												.Where(t => t.Setting.Include == include)
+												.Sum(t => (decimal?)t.Hours) ?? 0
+								});
+				var results = query.ToList();
+
+				Assert.That(results.Count, Is.EqualTo(2));
+				Assert.That(results.Single(x => x.Job.Name == "Big Job").Hours, Is.EqualTo(15));
+				Assert.That(results.Single(x => x.Job.Name == "Small Job").Hours, Is.EqualTo(7));
+			}
+		}
+
+		[Test]
+		public void CoalesceOnIdSubselectSum()
+		{
+			AssertDialect();
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var query = session.Query<Job>()
+								.Select(j => new
+								{
+									Job = j,
+									Hours = session.Query<TimeRecord>()
+												.Where(t => ((Guid?)t.ActualJob.Id ?? t.Project.Job.Id) == j.Id)
+												.Sum(t => (decimal?)t.Hours) ?? 0
+								});
+				var results = query.ToList();
+
+				Assert.That(results.Count, Is.EqualTo(2));
+				Assert.That(results.Single(x => x.Job.Name == "Big Job").Hours, Is.EqualTo(15));
+				Assert.That(results.Single(x => x.Job.Name == "Small Job").Hours, Is.EqualTo(7));
+			}
+		}
+
+		[Test]
+		public void CoalesceOnIdSubselectSumWithExtraJoin()
+		{
+			AssertDialect();
+			using (var session = OpenSession())
+			using (session.BeginTransaction())
+			{
+				var include = session.Query<TimeInclude>().Single();
+
+				var query = session.Query<Job>()
+								.Select(j => new
+								{
+									Job = j,
+									Hours = session.Query<TimeRecord>()
+												.Where(t => ((Guid?)t.ActualJob.Id ?? t.Project.Job.Id) == j.Id)
+												.Where(t => t.Setting.Include == include)
+												.Sum(t => (decimal?)t.Hours) ?? 0
+								});
+				var results = query.ToList();
+
+				Assert.That(results.Count, Is.EqualTo(2));
+				Assert.That(results.Single(x => x.Job.Name == "Big Job").Hours, Is.EqualTo(15));
+				Assert.That(results.Single(x => x.Job.Name == "Small Job").Hours, Is.EqualTo(7));
+			}
+		}
+
+		void AssertDialect()
+		{
+			if (Dialect is MsSqlCeDialect) Assert.Ignore(Dialect.GetType() + " does not support this type of query");
+		}
+	}
+}

src/NHibernate.Test/NHibernate.Test.csproj

@@ -742,6 +742,8 @@
     <Compile Include="NHSpecificTest\NH3912\ReusableBatcherFixture.cs" />
     <Compile Include="NHSpecificTest\NH3918\Model.cs" />
     <Compile Include="NHSpecificTest\NH3918\FixtureByCode.cs" />
+    <Compile Include="NHSpecificTest\NH3889\Entity.cs" />
+    <Compile Include="NHSpecificTest\NH3889\FixtureByCode.cs" />
     <Compile Include="NHSpecificTest\NH3414\Entity.cs" />
     <Compile Include="NHSpecificTest\NH3414\FixtureByCode.cs" />
     <Compile Include="NHSpecificTest\NH2218\Fixture.cs" />

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

@@ -123,11 +123,16 @@ query
 // The query / subquery rule. Pops the current 'from node' context 
 // (list of aliases).
 unionedQuery!
+	@init{
+		bool oldInSelect = _inSelect;
+		_inSelect = false;
+	}
 	@after {
 		// Antlr note: #x_in refers to the input AST, #x refers to the output AST
 		BeforeStatementCompletion( "select" );
 		ProcessQuery( $s.tree, $unionedQuery.tree );
 		AfterStatementCompletion( "select" );
+		_inSelect = oldInSelect;
 	}
 	: ^( QUERY { BeforeStatement( "select", SELECT ); }
 			// The first phase places the FROM first to make processing the SELECT simpler.
@@ -189,11 +194,10 @@ selectClause!
 	;
 
 selectExprList @init{
-		bool oldInSelect = _inSelect;
 		_inSelect = true;
 	}
 	: ( selectExpr | aliasedSelectExpr )+ {
-		_inSelect = oldInSelect;
+		_inSelect = false;
 	}
 	;