FIxes issue where an invariant property type was being validated with a culture when that would always fail. Fixes issue when saving a content type to ensure that a property type is never both variant and invariant. Adds test.

src/Umbraco.Web/Models/Mapping/PropertyTypeVariationsResolver.cs

@@ -5,18 +5,18 @@ using ContentVariation = Umbraco.Core.Models.ContentVariation;
 
 namespace Umbraco.Web.Models.Mapping
 {
+    /// <summary>
+    /// Returns the <see cref="ContentVariation"/> for a <see cref="PropertyType"/>
+    /// </summary>
     internal class PropertyTypeVariationsResolver: IValueResolver<PropertyTypeBasic, PropertyType, ContentVariation>
     {
         public ContentVariation Resolve(PropertyTypeBasic source, PropertyType destination, ContentVariation destMember, ResolutionContext context)
         {
-            //this will always be the case, a content type will always be allowed to be invariant
-            var result = ContentVariation.InvariantNeutral;
-
-            if (source.AllowCultureVariant)
-            {
-                result |= ContentVariation.CultureNeutral;
-            }
-
+            //A property type should only be one type of culture variation.
+            //If a property type allows both variant and invariant then it generally won't be able to save because validation
+            //occurs when performing something like IContent.TryPublishAllValues and it will result in validation problems because
+            //the invariant value will not be set since in the UI only the variant values are edited if it supports it.
+            var result = source.AllowCultureVariant ? ContentVariation.CultureNeutral : ContentVariation.InvariantNeutral;
             return result;
         }
     }