Fixes U4-2053

src/Umbraco.Core/Models/ContentType.cs

@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.Serialization;
-using Umbraco.Core.Persistence.Mappers;
 
 namespace Umbraco.Core.Models
 {
@@ -16,12 +15,22 @@ namespace Umbraco.Core.Models
     {
         private int _defaultTemplate;
         private IEnumerable<ITemplate> _allowedTemplates;
-
+        
+        /// <summary>
+        /// Constuctor for creating a ContentType with the parent's id.
+        /// </summary>
+        /// <remarks>You usually only want to use this for creating ContentTypes at the root.</remarks>
+        /// <param name="parentId"></param>
         public ContentType(int parentId) : base(parentId)
         {
             _allowedTemplates = new List<ITemplate>();
         }
 
+        /// <summary>
+        /// Constuctor for creating a ContentType with the parent as an inherited type.
+        /// </summary>
+        /// <remarks>Use this to ensure inheritance from parent.</remarks>
+        /// <param name="parent"></param>
 		public ContentType(IContentType parent) : base(parent)
 		{
 			_allowedTemplates = new List<ITemplate>();

src/Umbraco.Core/Models/ContentTypeCompositionBase.cs

@@ -20,8 +20,10 @@ namespace Umbraco.Core.Models
         {
         }
 
-		protected ContentTypeCompositionBase(IContentTypeBase parent) : base(parent)
+        protected ContentTypeCompositionBase(IContentTypeComposition parent)
+            : base(parent)
 		{
+		    AddContentType(parent);
 		}
 
         private static readonly PropertyInfo ContentTypeCompositionSelector =

src/Umbraco.Core/Models/MediaType.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Runtime.Serialization;
-using Umbraco.Core.Persistence.Mappers;
 
 namespace Umbraco.Core.Models
 {
@@ -11,10 +10,20 @@ namespace Umbraco.Core.Models
     [DataContract(IsReference = true)]
     public class MediaType : ContentTypeCompositionBase, IMediaType
     {
+        /// <summary>
+        /// Constuctor for creating a MediaType with the parent's id.
+        /// </summary>
+        /// <remarks>You usually only want to use this for creating MediaTypes at the root.</remarks>
+        /// <param name="parentId"></param>
         public MediaType(int parentId) : base(parentId)
         {
         }
 
+        /// <summary>
+        /// Constuctor for creating a MediaType with the parent as an inherited type.
+        /// </summary>
+        /// <remarks>Use this to ensure inheritance from parent.</remarks>
+        /// <param name="parent"></param>
 		public MediaType(IMediaType parent) : base(parent)
 		{
 		}

src/Umbraco.Web/umbraco.presentation/umbraco/create/nodetypeTasks.cs

@@ -47,13 +47,16 @@ namespace umbraco
         {
             //NOTE: TypeID is the parent id!
             //NOTE: ParentID is aparently a flag to determine if we are to create a template! Hack much ?! :P
-            var contentType = new ContentType(TypeID != 0 ? TypeID : -1)
-                {
-                    CreatorId = _userID,
-                    Alias = Alias.Replace("'", "''"),
-                    Icon = UmbracoSettings.IconPickerBehaviour == IconPickerBehaviour.HideFileDuplicates ? ".sprTreeFolder" : "folder.gif",
-                    Name = Alias.Replace("'", "''")
-                };
+            var parentId = TypeID != 0 ? TypeID : -1;
+            var contentType = parentId == -1
+                                  ? new ContentType(-1)
+                                  : new ContentType(ApplicationContext.Current.Services.ContentTypeService.GetContentType(parentId));
+            contentType.CreatorId = _userID;
+            contentType.Alias = Alias.Replace("'", "''");
+            contentType.Name = Alias.Replace("'", "''");
+            contentType.Icon = UmbracoSettings.IconPickerBehaviour == IconPickerBehaviour.HideFileDuplicates
+                                   ? ".sprTreeFolder"
+                                   : "folder.gif";
 
             // Create template?
             if (ParentID == 1)