Contribution by Piotr.

Fix workitem #17872: Null shape added to Zone causes NotImplementedException being thrown (return to change listing).
Added handling of null shapes. If shape that gets passed to Add method is null - it is simply ignored.

--HG--
branch : contributions

src/Orchard/DisplayManagement/Shapes/Shape.cs

@@ -19,6 +19,11 @@ namespace Orchard.DisplayManagement.Shapes {
         public virtual IEnumerable<dynamic> Items { get { return _items; } }
 
         public virtual Shape Add(object item, string position = DefaultPosition) {
+            // pszmyd: Ignoring null shapes 
+            if (item == null) {
+                return this;
+            }
+
             try {
                 // todo: (sebros) this is a temporary implementation to prevent common known scenarios throwing exceptions. The final solution would need to filter based on the fact that it is a Shape instance
                 if ( item is MvcHtmlString ||

src/Orchard/UI/IPage.cs

@@ -35,7 +35,8 @@ namespace Orchard.UI {
         public virtual string ZoneName { get; set; }
 
         public IZone Add(Action<HtmlHelper> action, string position) {
-            throw new NotImplementedException();
+            // pszmyd: Replaced the NotImplementedException with simply doing nothing
+            return this;
         }
     }
 }

src/Orchard/UI/Zones/ZoneHoldingBehavior.cs

@@ -89,6 +89,10 @@ namespace Orchard.UI.Zones {
             public override object InvokeMember(Func<object> proceed, object self, string name, INamedEnumerable<object> args) {
                 var argsCount = args.Count();
                 if (name == "Add" && (argsCount == 1 || argsCount == 2)) {
+                    // pszmyd: Ignore null shapes
+                    if (args.First() == null)
+                        return _parent;
+
                     dynamic parent = _parent;
 
                     dynamic zone = _zoneFactory();