NH-3860 - Add missing EntityName to IManyToOneMapper

Fixes #1182

Author: hazzik

src/NHibernate.Test/MappingByCode/MappersTests/ManyToOneMapperTest.cs

@@ -37,6 +37,16 @@ public void AssignCascadeStyle()
 			mapper.Cascade(Mapping.ByCode.Cascade.Persist | Mapping.ByCode.Cascade.Remove);
 			Assert.That(hbm.cascade.Split(',').Select(w => w.Trim()), Contains.Item("persist").And.Contains("delete"));
 		}
+		
+		[Test]
+		public void AssignEntityName()
+		{
+			var hbmMapping = new HbmMapping();
+			var hbm = new HbmManyToOne();
+			IManyToOneMapper mapper = new ManyToOneMapper(null, hbm, hbmMapping);
+			mapper.EntityName("MyEntity");
+			Assert.That(hbm.EntityName, Is.EqualTo("MyEntity"));
+		}
 
 		[Test]
 		public void CanSetAccessor()

src/NHibernate/Mapping/ByCode/IManyToOneMapper.cs

@@ -1,3 +1,6 @@
+using System;
+using NHibernate.Mapping.ByCode.Impl;
+
 namespace NHibernate.Mapping.ByCode
 {
 	public interface IManyToOneMapper : IEntityPropertyMapper, IColumnsMapper
@@ -10,7 +13,6 @@ public interface IManyToOneMapper : IEntityPropertyMapper, IColumnsMapper
 		/// Useful when the property is an interface and you need the mapping to a concrete class mapped as entity.
 		/// </remarks>
 		void Class(System.Type entityType);
-
 		void Cascade(Cascade cascadeStyle);
 		void NotNullable(bool notnull);
 		void Unique(bool unique);
@@ -24,5 +26,29 @@ public interface IManyToOneMapper : IEntityPropertyMapper, IColumnsMapper
 		void ForeignKey(string foreignKeyName);
 		void PropertyRef(string propertyReferencedName);
 		void NotFound(NotFoundMode mode);
+		//6.0 TODO: Uncomment
+		//void EntityName(string entityName);
+	}
+
+	//6.0 TODO: Remove
+	public static class ManyToOneMapperExtensions
+	{
+		public static void EntityName(this IManyToOneMapper mapper, string entityName)
+		{
+			switch (mapper)
+			{
+				case KeyManyToOneMapper m:
+					m.EntityName(entityName);
+					break;
+				case ManyToOneMapper m:
+					m.EntityName(entityName);
+					break;
+				default:
+					throw new ArgumentException(
+						"Only mappers of type 'KeyManyToOneMapper' and 'ManyToOneMapper' are supported, got " +
+						mapper.GetType().FullName,
+						nameof(mapper));
+			}
+		}
 	}
 }

src/NHibernate/Mapping/ByCode/Impl/KeyManyToOneMapper.cs

@@ -46,6 +46,11 @@ public void Class(System.Type entityType)
 			_manyToOne.@class = entityType.GetShortClassName(_mapDoc);
 		}
 
+		public void EntityName(string entityName)
+		{
+			_manyToOne.entityname = entityName;
+		}
+
 		public void Cascade(Cascade cascadeStyle)
 		{
 			// not supported by HbmKeyManyToOne

src/NHibernate/Mapping/ByCode/Impl/ManyToOneMapper.cs

@@ -43,6 +43,11 @@ public void Class(System.Type entityType)
 			_manyToOne.@class = entityType.GetShortClassName(_mapDoc);
 		}
 
+		public void EntityName(string entityName)
+		{
+			_manyToOne.entityname = entityName;
+		}
+
 		public void Cascade(Cascade cascadeStyle)
 		{
 			_manyToOne.cascade = cascadeStyle.ToCascadeString();