From aaa90bea146ca19dce6b9c559e163e03b87dfa8b Mon Sep 17 00:00:00 2001
From: "agrath@gmail.com" <unknown@kiln.example.com>
Date: Sun, 27 Feb 2011 22:55:50 -1300
Subject: [PATCH] More graceful handling of missing properties in .Where -
 TryGetMember now returns DynamicNull Only return DynamicNull if property
 truely doesn't exist - if it does exist and has no value, still return null

---
 .../RazorDynamicNode/DynamicNode.cs           | 20 +++++++++++++------
 .../RazorDynamicNode/DynamicNull.cs           |  4 ++++
 .../RazorDynamicNode/DynamicQueryable.cs      |  2 +-
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicNode.cs b/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicNode.cs
index 28af0dd70e..55e60d2a28 100644
--- a/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicNode.cs
+++ b/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicNode.cs
@@ -205,20 +205,21 @@ namespace umbraco.MacroEngines
         {
 
             var name = binder.Name;
+            result = null; //this will never be returned
 
             if (name == "ChildrenAsList" || name == "Children")
             {
                 result = GetChildrenAsList;
                 return true;
             }
-
+            bool propertyExists = false;
             if (n != null)
             {
-                var data = n.GetProperty(name);
+                var data = n.GetProperty(name, out propertyExists);
                 // check for nicer support of Pascal Casing EVEN if alias is camelCasing:
-                if (data == null && name.Substring(0, 1).ToUpper() == name.Substring(0, 1))
+                if (data == null && name.Substring(0, 1).ToUpper() == name.Substring(0, 1) && !propertyExists)
                 {
-                    data = n.GetProperty(name.Substring(0, 1).ToLower() + name.Substring((1)));
+                    data = n.GetProperty(name.Substring(0, 1).ToLower() + name.Substring((1)), out propertyExists);
                 }
 
                 if (data != null)
@@ -267,8 +268,15 @@ namespace umbraco.MacroEngines
             //at this point, we're going to return null
             //instead, we return a DynamicNull - see comments in that file
             //this will let things like Model.ChildItem work and return nothing instead of crashing
-            result = new DynamicNull();
-            //changed this to a return true because it breaks testing when using .Children().Random().propertyName
+            if (!propertyExists && result == null)
+            {
+                //.Where explictly checks for this type
+                //and will make it false
+                //which means backwards equality (&& property != true) will pass
+                //forwwards equality (&& property or && property == true) will fail
+                result = new DynamicNull();
+                return true;
+            }
             return true;
         }
 
diff --git a/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicNull.cs b/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicNull.cs
index c93ce3389a..7bfe6462c5 100644
--- a/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicNull.cs
+++ b/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicNull.cs
@@ -26,5 +26,9 @@ namespace umbraco.MacroEngines
         {
             return this;
         }
+        public override string ToString()
+        {
+            return string.Empty;
+        }
     }
 }
diff --git a/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicQueryable.cs b/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicQueryable.cs
index f02c6de106..1f1833869c 100644
--- a/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicQueryable.cs
+++ b/umbraco.MacroEngines.Juno/RazorDynamicNode/DynamicQueryable.cs
@@ -1471,7 +1471,7 @@ namespace System.Linq.Dynamic
                      Expression.IfThen(
                         Expression.TypeEqual(result, typeof(DynamicNull)),
                         Expression.Assign(result,
-                            Expression.Constant(true, typeof(object))
+                            Expression.Constant(false, typeof(object))
                         )
                      ),
                      Expression.Return(blockReturnLabel, result),