Restoring modelvalidation node.

src/Microsoft.AspNet.Mvc.Abstractions/ModelBinding/ModelBindingResult.cs

@@ -16,10 +16,25 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// <param name="isModelSet">A value that represents if the model has been set by the
         /// <see cref="IModelBinder"/>.</param>
         public ModelBindingResult(object model, string key, bool isModelSet)
+            : this (model, key, isModelSet, validationNode: null)
+        {
+        }
+
+        /// <summary>
+        /// Creates a new <see cref="ModelBindingResult"/>.
+        /// </summary>
+        /// <param name="model">The model which was created by the <see cref="IModelBinder"/>.</param>
+        /// <param name="key">The key using which was used to attempt binding the model.</param>
+        /// <param name="isModelSet">A value that represents if the model has been set by the
+        /// <see cref="IModelBinder"/>.</param>
+        /// <param name="validationNode">A <see cref="ModelValidationNode"/> which captures the validation information.
+        /// </param>
+        public ModelBindingResult(object model, string key, bool isModelSet, ModelValidationNode validationNode)
         {
             Model = model;
             Key = key;
             IsModelSet = isModelSet;
+            ValidationNode = validationNode;
         }
 
         /// <summary>
@@ -47,5 +62,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         /// </para>
         /// </summary>
         public bool IsModelSet { get; }
+
+        /// <summary>
+        /// A <see cref="ModelValidationNode"/> associated with the current <see cref="ModelBindingResult"/>.
+        /// </summary>
+        public ModelValidationNode ValidationNode { get; }
     }
 }

src/Microsoft.AspNet.Mvc.Abstractions/ModelBinding/ModelValidationNode.cs

@@ -0,0 +1,76 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Collections.Generic;
+using Microsoft.Framework.Internal;
+
+namespace Microsoft.AspNet.Mvc.ModelBinding
+{
+    /// <summary>
+    /// Captures the validation information for a particular model.
+    /// </summary>
+    public class ModelValidationNode
+    {
+        /// <summary>
+        /// Creates a new instance of <see cref="ModelValidationNode"/>.
+        /// </summary>
+        /// <param name="key">The key that will be used by the validation system to find <see cref="ModelState"/>
+        /// entries.</param>
+        /// <param name="modelMetadata">The <see cref="ModelMetadata"/> for the <paramref name="model"/>.</param>
+        /// <param name="model">The model object which is to be validated.</param>
+        public ModelValidationNode([NotNull] string key, [NotNull] ModelMetadata modelMetadata, object model)
+            : this (key, modelMetadata, model, new List<ModelValidationNode>())
+        {
+        }
+
+        /// <summary>
+        /// Creates a new instance of <see cref="ModelValidationNode"/>.
+        /// </summary>
+        /// <param name="key">The key that will be used by the validation system to add
+        /// <see cref="ModelStateDictionary"/> entries.</param>
+        /// <param name="modelMetadata">The <see cref="ModelMetadata"/> for the <paramref name="model"/>.</param>
+        /// <param name="model">The model object which will be validated.</param>
+        /// <param name="childNodes">A collection of child nodes.</param>
+        public ModelValidationNode(
+            [NotNull] string key,
+            [NotNull] ModelMetadata modelMetadata,
+            object model,
+            [NotNull] IList<ModelValidationNode> childNodes)
+        {
+            Key = key;
+            ModelMetadata = modelMetadata;
+            ChildNodes = childNodes;
+            Model = model;
+        }
+
+        /// <summary>
+        /// Gets the key used for adding <see cref="ModelStateDictionary"/> entries.
+        /// </summary>
+        public string Key { get; }
+
+        /// <summary>
+        /// Gets the <see cref="ModelMetadata"/>.
+        /// </summary>
+        public ModelMetadata ModelMetadata { get; }
+
+        /// <summary>
+        /// Gets the model instance which is to be validated.
+        /// </summary>
+        public object Model { get; }
+
+        /// <summary>
+        /// Gets the child nodes.
+        /// </summary>
+        public IList<ModelValidationNode> ChildNodes { get; }
+
+        /// <summary>
+        /// Gets or sets a value that indicates whether all properties of the model should be validated.
+        /// </summary>
+        public bool ValidateAllProperties { get; set; }
+
+        /// <summary>
+        /// Gets or sets a value that indicates whether validation should be suppressed.
+        /// </summary>
+        public bool SuppressValidation { get; set; }
+    }
+}

src/Microsoft.AspNet.Mvc.Abstractions/ModelBinding/Validation/ModelValidationContext.cs

@@ -10,23 +10,21 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
         public ModelValidationContext(
             [NotNull] ModelBindingContext bindingContext,
             [NotNull] ModelExplorer modelExplorer)
-            : this(bindingContext.ModelName,
-                   bindingContext.BindingSource,
-                   bindingContext.OperationBindingContext.ValidatorProvider,
-                   bindingContext.ModelState,
-                   modelExplorer)
+            : this(
+                 bindingContext.BindingSource,
+                 bindingContext.OperationBindingContext.ValidatorProvider,
+                 bindingContext.ModelState,
+                 modelExplorer)
         {
         }
 
         public ModelValidationContext(
-            string rootPrefix,
             BindingSource bindingSource,
             [NotNull] IModelValidatorProvider validatorProvider,
             [NotNull] ModelStateDictionary modelState,
             [NotNull] ModelExplorer modelExplorer)
         {
             ModelState = modelState;
-            RootPrefix = rootPrefix;
             ValidatorProvider = validatorProvider;
             ModelExplorer = modelExplorer;
             BindingSource = bindingSource;
@@ -45,7 +43,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             [NotNull] ModelExplorer modelExplorer)
         {
             return new ModelValidationContext(
-                parentContext.RootPrefix,
                 modelExplorer.Metadata.BindingSource,
                 parentContext.ValidatorProvider,
                 parentContext.ModelState,
@@ -56,8 +53,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
 
         public ModelStateDictionary ModelState { get; }
 
-        public string RootPrefix { get; set; }
-
         public BindingSource BindingSource { get; set; }
 
         public IModelValidatorProvider ValidatorProvider { get; }

src/Microsoft.AspNet.Mvc.Core/Controller.cs

@@ -1336,13 +1336,17 @@ namespace Microsoft.AspNet.Mvc
                 modelName);
 
             var validationContext = new ModelValidationContext(
-                modelName,
                 bindingSource: null,
                 validatorProvider: BindingContext.ValidatorProvider,
                 modelState: ModelState,
                 modelExplorer: modelExplorer);
 
-            ObjectValidator.Validate(validationContext);
+            ObjectValidator.Validate(
+                validationContext,
+                new ModelValidationNode(modelName, modelExplorer.Metadata, model)
+                {
+                    ValidateAllProperties = true
+                });
             return ModelState.IsValid;
         }
 

src/Microsoft.AspNet.Mvc.Core/DefaultControllerActionArgumentBinder.cs

@@ -90,12 +90,11 @@ namespace Microsoft.AspNet.Mvc
                     modelBindingResult.Model);
 
                 var validationContext = new ModelValidationContext(
-                    key,
                     modelBindingContext.BindingSource,
                     operationContext.ValidatorProvider,
                     modelState,
                     modelExplorer);
-                _validator.Validate(validationContext);
+                _validator.Validate(validationContext, modelBindingResult.ValidationNode);
             }
 
             return modelBindingResult;

src/Microsoft.AspNet.Mvc.Core/ModelBinding/BinderTypeBasedModelBinder.cs

@@ -46,7 +46,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             var result = await modelBinder.BindModelAsync(bindingContext);
 
             var modelBindingResult = result != null ?
-                new ModelBindingResult(result.Model, result.Key, result.IsModelSet) :
+                new ModelBindingResult(result.Model, result.Key, result.IsModelSet, result.ValidationNode) :
                 new ModelBindingResult(model: null, key: bindingContext.ModelName, isModelSet: false);
 
             // A model binder was specified by metadata and this binder handles all such cases.

src/Microsoft.AspNet.Mvc.Core/ModelBinding/BindingSourceModelBinder.cs

@@ -81,7 +81,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
             var modelBindingResult =
                 result != null ?
-                    new ModelBindingResult(result.Model, result.Key, result.IsModelSet) :
+                    new ModelBindingResult(result.Model, result.Key, result.IsModelSet, result.ValidationNode) :
                     new ModelBindingResult(model: null, key: context.ModelName, isModelSet: false);
 
             // This model binder is the only handler for its binding source.

src/Microsoft.AspNet.Mvc.Core/ModelBinding/BodyModelBinder.cs

@@ -54,11 +54,21 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
                 var isTopLevelObject = bindingContext.ModelMetadata.ContainerType == null;
 
-                // For compatibility with MVC 5.0 for top level object we want to consider an empty key instead of 
+                // For compatibility with MVC 5.0 for top level object we want to consider an empty key instead of
                 // the parameter name/a custom name. In all other cases (like when binding body to a property) we
                 // consider the entire ModelName as a prefix.
                 var modelBindingKey = isTopLevelObject ? string.Empty : bindingContext.ModelName;
-                return new ModelBindingResult(model, key: modelBindingKey, isModelSet: true);
+
+                var validationNode = new ModelValidationNode(modelBindingKey, bindingContext.ModelMetadata, model)
+                {
+                    ValidateAllProperties = true
+                };
+
+                return new ModelBindingResult(
+                    model,
+                    key: modelBindingKey,
+                    isModelSet: true,
+                    validationNode: validationNode);
             }
             catch (Exception ex)
             {

src/Microsoft.AspNet.Mvc.Core/ModelBinding/ByteArrayModelBinder.cs

@@ -39,7 +39,12 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             try
             {
                 var model = Convert.FromBase64String(value);
-                return new ModelBindingResult(model, bindingContext.ModelName, isModelSet: true);
+
+                // We do not need to set an explict ModelValidationNode since CompositeModelBinder does that automatically.
+                return new ModelBindingResult(
+                    model,
+                    bindingContext.ModelName,
+                    isModelSet: true);
             }
             catch (Exception ex)
             {

src/Microsoft.AspNet.Mvc.Core/ModelBinding/CollectionModelBinder.cs

@@ -31,16 +31,19 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             var valueProviderResult = await bindingContext.ValueProvider.GetValueAsync(bindingContext.ModelName);
 
             IEnumerable<TElement> boundCollection;
+            CollectionResult result;
             if (valueProviderResult == null)
             {
-                boundCollection = await BindComplexCollection(bindingContext);
+                result = await BindComplexCollection(bindingContext);
+                boundCollection = result.Model;
             }
             else
             {
-                boundCollection = await BindSimpleCollection(
+                result = await BindSimpleCollection(
                     bindingContext,
                     valueProviderResult.RawValue,
                     valueProviderResult.Culture);
+                boundCollection = result.Model;
             }
 
             var model = bindingContext.Model;
@@ -54,12 +57,16 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 CopyToModel(model, boundCollection);
             }
 
-            return new ModelBindingResult(model, bindingContext.ModelName, isModelSet: true);
+            return new ModelBindingResult(
+                model,
+                bindingContext.ModelName,
+                isModelSet: true,
+                validationNode: result?.ValidationNode);
         }
 
         // Used when the ValueProvider contains the collection to be bound as a single element, e.g. the raw value
         // is [ "1", "2" ] and needs to be converted to an int[].
-        internal async Task<IEnumerable<TElement>> BindSimpleCollection(
+        internal async Task<CollectionResult> BindSimpleCollection(
             ModelBindingContext bindingContext,
             object rawValue,
             CultureInfo culture)
@@ -74,6 +81,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             var metadataProvider = bindingContext.OperationBindingContext.MetadataProvider;
             var elementMetadata = metadataProvider.GetMetadataForType(typeof(TElement));
 
+            var validationNode = new ModelValidationNode(
+                bindingContext.ModelName,
+                bindingContext.ModelMetadata,
+                boundCollection);
             var rawValueArray = RawValueToObjectArray(rawValue);
             foreach (var rawValueElement in rawValueArray)
             {
@@ -91,18 +102,26 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 object boundValue = null;
                 var result =
                     await bindingContext.OperationBindingContext.ModelBinder.BindModelAsync(innerBindingContext);
-                if (result != null)
+                if (result != null && result.IsModelSet)
                 {
                     boundValue = result.Model;
+                    if (result.ValidationNode != null)
+                    {
+                        validationNode.ChildNodes.Add(result.ValidationNode);
+                    }
                 }
                 boundCollection.Add(ModelBindingHelper.CastOrDefault<TElement>(boundValue));
             }
 
-            return boundCollection;
+            return new CollectionResult
+            {
+                ValidationNode = validationNode,
+                Model = boundCollection
+            };
         }
 
         // Used when the ValueProvider contains the collection to be bound as multiple elements, e.g. foo[0], foo[1].
-        private async Task<IEnumerable<TElement>> BindComplexCollection(ModelBindingContext bindingContext)
+        private async Task<CollectionResult> BindComplexCollection(ModelBindingContext bindingContext)
         {
             var indexPropertyName = ModelNames.CreatePropertyModelName(bindingContext.ModelName, "index");
             var valueProviderResultIndex = await bindingContext.ValueProvider.GetValueAsync(indexPropertyName);
@@ -111,7 +130,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             return await BindComplexCollectionFromIndexes(bindingContext, indexNames);
         }
 
-        internal async Task<IEnumerable<TElement>> BindComplexCollectionFromIndexes(
+        internal async Task<CollectionResult> BindComplexCollectionFromIndexes(
             ModelBindingContext bindingContext,
             IEnumerable<string> indexNames)
         {
@@ -131,6 +150,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             var elementMetadata = metadataProvider.GetMetadataForType(typeof(TElement));
 
             var boundCollection = new List<TElement>();
+            var validationNode = new ModelValidationNode(
+                bindingContext.ModelName,
+                bindingContext.ModelMetadata,
+                boundCollection);
             foreach (var indexName in indexNames)
             {
                 var fullChildName = ModelNames.CreateIndexModelName(bindingContext.ModelName, indexName);
@@ -146,10 +169,14 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
                 var result =
                     await bindingContext.OperationBindingContext.ModelBinder.BindModelAsync(childBindingContext);
-                if (result != null)
+                if (result != null && result.IsModelSet)
                 {
                     didBind = true;
                     boundValue = result.Model;
+                    if (result.ValidationNode != null)
+                    {
+                        validationNode.ChildNodes.Add(result.ValidationNode);
+                    }
                 }
 
                 // infinite size collection stops on first bind failure
@@ -161,7 +188,18 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 boundCollection.Add(ModelBindingHelper.CastOrDefault<TElement>(boundValue));
             }
 
-            return boundCollection;
+            return new CollectionResult
+            {
+                ValidationNode = validationNode,
+                Model = boundCollection
+            };
+        }
+
+        internal class CollectionResult
+        {
+            public ModelValidationNode ValidationNode { get; set; }
+
+            public IEnumerable<TElement> Model { get; set; }
         }
 
         /// <summary>

src/Microsoft.AspNet.Mvc.Core/ModelBinding/CompositeModelBinder.cs

@@ -55,6 +55,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             bindingContext.OperationBindingContext.BodyBindingState =
                 newBindingContext.OperationBindingContext.BodyBindingState;
 
+            var bindingKey = bindingContext.ModelName;
             if (modelBindingResult.IsModelSet)
             {
                 // Update the model state key if we are bound using an empty prefix and it is a complex type.
@@ -78,15 +79,28 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                     // In this case, for the model parameter the key would be SimpleType instead of model.SimpleType.
                     // (i.e here the prefix for the model key is empty).
                     // For the id parameter the key would be id.
-                    return modelBindingResult;
+                    bindingKey = string.Empty;
                 }
             }
 
-            // Fall through to update the ModelBindingResult's key.
+            // Update the model validation node if the model binding result was set but no validation node was provided.
+            // This would typically be the case where leaf level model binders, do not have to add a validation node
+            // for validation to take effect. The composite being the entry point for model binders, takes care or
+            // adding missing validation nodes.
+            var modelValidationNode = modelBindingResult.ValidationNode;
+            if (modelBindingResult.IsModelSet && modelValidationNode == null)
+            {
+                modelValidationNode = new ModelValidationNode(
+                    bindingKey,
+                    bindingContext.ModelMetadata,
+                    modelBindingResult.Model);
+            }
+
             return new ModelBindingResult(
                 modelBindingResult.Model,
-                bindingContext.ModelName,
-                modelBindingResult.IsModelSet);
+                bindingKey,
+                modelBindingResult.IsModelSet,
+                modelValidationNode);
         }
 
         private async Task<ModelBindingResult> TryBind(ModelBindingContext bindingContext)

src/Microsoft.AspNet.Mvc.Core/ModelBinding/GenericModelBinder.cs

@@ -20,7 +20,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 var result = await binder.BindModelAsync(bindingContext);
 
                 var modelBindingResult = result != null ?
-                    new ModelBindingResult(result.Model, result.Key, result.IsModelSet) :
+                    new ModelBindingResult(result.Model, result.Key, result.IsModelSet, result.ValidationNode) :
                     new ModelBindingResult(model: null, key: bindingContext.ModelName, isModelSet: false);
 
                 // Were able to resolve a binder type.

src/Microsoft.AspNet.Mvc.Core/ModelBinding/HeaderModelBinder.cs

@@ -51,7 +51,21 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 }
             }
 
-            return Task.FromResult(new ModelBindingResult(model, bindingContext.ModelName, isModelSet: model != null));
+            ModelValidationNode validationNode = null;
+            if (model != null)
+            {
+                validationNode = new ModelValidationNode(
+                    bindingContext.ModelName,
+                    bindingContext.ModelMetadata,
+                    model);
+            }
+
+            return Task.FromResult(
+                new ModelBindingResult(
+                    model,
+                    bindingContext.ModelName,
+                    isModelSet: model != null,
+                    validationNode: validationNode));
         }
     }
 }

src/Microsoft.AspNet.Mvc.Core/ModelBinding/KeyValuePairModelBinder.cs

@@ -15,8 +15,9 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                                                       typeof(KeyValuePair<TKey, TValue>),
                                                       allowNullModel: true);
 
-            var keyResult = await TryBindStrongModel<TKey>(bindingContext, "Key");
-            var valueResult = await TryBindStrongModel<TValue>(bindingContext, "Value");
+            var childNodes = new List<ModelValidationNode>();
+            var keyResult = await TryBindStrongModel<TKey>(bindingContext, "Key", childNodes);
+            var valueResult = await TryBindStrongModel<TValue>(bindingContext, "Value", childNodes);
 
             if (keyResult.IsModelSet && valueResult.IsModelSet)
             {
@@ -24,8 +25,20 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                     ModelBindingHelper.CastOrDefault<TKey>(keyResult.Model),
                     ModelBindingHelper.CastOrDefault<TValue>(valueResult.Model));
 
+                // Update the model for the top level validation node.
+                var modelValidationNode =
+                    new ModelValidationNode(
+                        bindingContext.ModelName,
+                        bindingContext.ModelMetadata,
+                        model,
+                        childNodes);
+
                 // Success
-                return new ModelBindingResult(model, bindingContext.ModelName, isModelSet: true);
+                return new ModelBindingResult(
+                    model,
+                    bindingContext.ModelName,
+                    isModelSet: true,
+                    validationNode: modelValidationNode);
             }
             else if (!keyResult.IsModelSet && valueResult.IsModelSet)
             {
@@ -55,8 +68,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             }
         }
 
-        internal async Task<ModelBindingResult> TryBindStrongModel<TModel>(ModelBindingContext parentBindingContext,
-                                                                          string propertyName)
+        internal async Task<ModelBindingResult> TryBindStrongModel<TModel>(
+            ModelBindingContext parentBindingContext,
+            string propertyName,
+            List<ModelValidationNode> childNodes)
         {
             var propertyModelMetadata =
                 parentBindingContext.OperationBindingContext.MetadataProvider.GetMetadataForType(typeof(TModel));
@@ -72,6 +87,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 propertyBindingContext);
             if (modelBindingResult != null)
             {
+                if (modelBindingResult.ValidationNode != null)
+                {
+                    childNodes.Add(modelBindingResult.ValidationNode);
+                }
+
                 return modelBindingResult;
             }
 

src/Microsoft.AspNet.Mvc.Core/ModelBinding/MutableObjectModelBinder.cs

@@ -44,12 +44,18 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             EnsureModel(bindingContext);
             var result = await CreateAndPopulateDto(bindingContext, mutableObjectBinderContext.PropertyMetadata);
 
+            var validationNode = new ModelValidationNode(
+                bindingContext.ModelName,
+                bindingContext.ModelMetadata,
+                bindingContext.Model);
+
             // post-processing, e.g. property setters and hooking up validation
-            ProcessDto(bindingContext, (ComplexModelDto)result.Model);
+            ProcessDto(bindingContext, (ComplexModelDto)result.Model, validationNode);
             return new ModelBindingResult(
                 bindingContext.Model,
                 bindingContext.ModelName,
-                isModelSet: true);
+                isModelSet: true,
+                validationNode: validationNode);
         }
 
         /// <summary>
@@ -359,11 +365,14 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             return validationInfo;
         }
 
-        internal void ProcessDto(ModelBindingContext bindingContext, ComplexModelDto dto)
+        // Internal for testing.
+        internal ModelValidationNode ProcessDto(
+            ModelBindingContext bindingContext,
+            ComplexModelDto dto,
+            ModelValidationNode validationNode)
         {
             var metadataProvider = bindingContext.OperationBindingContext.MetadataProvider;
             var modelExplorer = metadataProvider.GetModelExplorerForType(bindingContext.ModelType, bindingContext.Model);
-
             var validationInfo = GetPropertyValidationInfo(bindingContext);
 
             // Eliminate provided properties from requiredProperties; leaving just *missing* required properties.
@@ -415,8 +424,20 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                         out requiredValidator);
 
                     SetProperty(bindingContext, modelExplorer, propertyMetadata, dtoResult, requiredValidator);
+
+                    var dtoValidationNode = dtoResult.ValidationNode;
+                    if (dtoValidationNode == null)
+                    {
+                        // Make sure that irrespective of if the properties of the model were bound with a value,
+                        // create a validation node so that these get validated.
+                        dtoValidationNode = new ModelValidationNode(dtoResult.Key, entry.Key, dtoResult.Model);
+                    }
+
+                    validationNode.ChildNodes.Add(dtoValidationNode);
                 }
             }
+
+            return validationNode;
         }
 
         /// <summary>

src/Microsoft.AspNet.Mvc.Core/ModelBinding/ServicesModelBinder.cs

@@ -26,7 +26,17 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
         {
             var requestServices = bindingContext.OperationBindingContext.HttpContext.RequestServices;
             var model = requestServices.GetRequiredService(bindingContext.ModelType);
-            return Task.FromResult(new ModelBindingResult(model, bindingContext.ModelName, isModelSet: true));
+            var validationNode =
+                new ModelValidationNode(bindingContext.ModelName, bindingContext.ModelMetadata, model)
+                {
+                    SuppressValidation = true
+                };
+
+            return Task.FromResult(new ModelBindingResult(
+                    model,
+                    bindingContext.ModelName,
+                    isModelSet: true,
+                    validationNode: validationNode));
         }
     }
 }

src/Microsoft.AspNet.Mvc.Core/ModelBinding/TypeConverterModelBinder.cs

@@ -30,7 +30,12 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             {
                 newModel = valueProviderResult.ConvertTo(bindingContext.ModelType);
                 ModelBindingHelper.ReplaceEmptyStringWithNull(bindingContext.ModelMetadata, ref newModel);
-                return new ModelBindingResult(newModel, bindingContext.ModelName, isModelSet: true);
+
+                // We do not need to set an explict ModelValidationNode since CompositeModelBinder does that automatically.
+                return new ModelBindingResult(
+                    newModel,
+                    bindingContext.ModelName,
+                    isModelSet: true);
             }
             catch (Exception ex)
             {

src/Microsoft.AspNet.Mvc.Core/ModelBinding/TypeMatchModelBinder.cs

@@ -19,7 +19,12 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             bindingContext.ModelState.SetModelValue(bindingContext.ModelName, valueProviderResult);
             var model = valueProviderResult.RawValue;
             ModelBindingHelper.ReplaceEmptyStringWithNull(bindingContext.ModelMetadata, ref model);
-            return new ModelBindingResult(model, bindingContext.ModelName, isModelSet: true);
+
+            // We do not need to set an explict ModelValidationNode since CompositeModelBinder does that automatically.
+            return new ModelBindingResult(
+                model,
+                bindingContext.ModelName,
+                isModelSet: true);
         }
 
         internal static async Task<ValueProviderResult> GetCompatibleValueProviderResult(ModelBindingContext context)

src/Microsoft.AspNet.Mvc.Core/ModelBinding/Validation/DefaultObjectValidator.cs

@@ -35,16 +35,19 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
         }
 
         /// <inheritdoc />
-        public void Validate([NotNull] ModelValidationContext modelValidationContext)
+        public void Validate(
+            [NotNull] ModelValidationContext modelValidationContext,
+            [NotNull] ModelValidationNode validationNode)
         {
             var validationContext = new ValidationContext()
             {
                 ModelValidationContext = modelValidationContext,
                 Visited = new HashSet<object>(ReferenceEqualityComparer.Instance),
+                ValidationNode = validationNode
             };
 
             ValidateNonVisitedNodeAndChildren(
-                modelValidationContext.RootPrefix,
+                validationNode.Key,
                 validationContext,
                 validators: null);
         }
@@ -54,19 +57,16 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             ValidationContext validationContext,
             IList<IModelValidator> validators)
         {
-            var modelValidationContext = validationContext.ModelValidationContext;
-            var modelExplorer = modelValidationContext.ModelExplorer;
-
             // Recursion guard to avoid stack overflows
             RuntimeHelpers.EnsureSufficientExecutionStack();
 
+            var modelValidationContext = validationContext.ModelValidationContext;
+            var modelExplorer = modelValidationContext.ModelExplorer;
             var modelState = modelValidationContext.ModelState;
-
-            var bindingSource = modelValidationContext.BindingSource;
-            if (bindingSource != null && !bindingSource.IsFromRequest)
+            var currentValidationNode = validationContext.ValidationNode;
+            if (currentValidationNode.SuppressValidation)
             {
-                // Short circuit if the metadata represents something that was not bound using request data.
-                // For example model bound using [FromServices]. Treat such objects as skipped.
+                // Short circuit if the node is marked to be suppressed
                 var validationState = modelState.GetFieldValidationState(modelKey);
                 if (validationState == ModelValidationState.Unvalidated)
                 {
@@ -88,22 +88,18 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             {
                 // The validators are not null in the case of validating an array. Since the validators are
                 // the same for all the elements of the array, we do not do GetValidators for each element,
-                // instead we just pass them over. See ValidateElements function.
-                var validatorProvider = modelValidationContext.ValidatorProvider;
-                var validatorProviderContext = new ModelValidatorProviderContext(modelExplorer.Metadata);
-                validatorProvider.GetValidators(validatorProviderContext);
-
-                validators = validatorProviderContext.Validators;
+                // instead we just pass them over.
+                validators = GetValidators(modelValidationContext.ValidatorProvider, modelExplorer.Metadata);
             }
 
-            // We don't need to recursively traverse the graph for null values
-            if (modelExplorer.Model == null)
+            // We don't need to recursively traverse the graph if there are no child nodes.
+            if (currentValidationNode.ChildNodes.Count == 0 && !currentValidationNode.ValidateAllProperties)
             {
                 return ShallowValidate(modelKey, modelExplorer, validationContext, validators);
             }
 
             // We don't need to recursively traverse the graph for types that shouldn't be validated
-            var modelType = modelExplorer.Model.GetType();
+            var modelType = modelExplorer.ModelType;
             if (IsTypeExcludedFromValidation(_excludeFilters, modelType))
             {
                 var result = ShallowValidate(modelKey, modelExplorer, validationContext, validators);
@@ -112,24 +108,14 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             }
 
             // Check to avoid infinite recursion. This can happen with cycles in an object graph.
+            // Note that this is only applicable in case the model is pre-existing (like in case of TryUpdateModel).
             if (validationContext.Visited.Contains(modelExplorer.Model))
             {
                 return true;
             }
 
             validationContext.Visited.Add(modelExplorer.Model);
-
-            // Validate the children first - depth-first traversal
-            var enumerableModel = modelExplorer.Model as IEnumerable;
-            if (enumerableModel == null)
-            {
-                isValid = ValidateProperties(modelKey, modelExplorer, validationContext);
-            }
-            else
-            {
-                isValid = ValidateElements(modelKey, enumerableModel, validationContext);
-            }
-
+            isValid = ValidateChildNodes(modelKey, modelExplorer, validationContext);
             if (isValid)
             {
                 // Don't bother to validate this node if children failed.
@@ -166,32 +152,49 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             }
         }
 
-        private bool ValidateProperties(
+        private IList<IModelValidator> GetValidators(IModelValidatorProvider provider, ModelMetadata metadata)
+        {
+            var validatorProviderContext = new ModelValidatorProviderContext(metadata);
+            provider.GetValidators(validatorProviderContext);
+            return validatorProviderContext.Validators;
+        }
+
+        private bool ValidateChildNodes(
             string currentModelKey,
             ModelExplorer modelExplorer,
             ValidationContext validationContext)
         {
             var isValid = true;
+            ExpandValidationNode(validationContext, modelExplorer);
 
-            foreach (var property in modelExplorer.Metadata.Properties)
+            IList<IModelValidator> validators = null;
+            if (modelExplorer.Metadata.IsCollectionType && modelExplorer.Model != null)
             {
-                var propertyExplorer = modelExplorer.GetExplorerForProperty(property.PropertyName);
-                var propertyMetadata = propertyExplorer.Metadata;
+                var enumerableModel = (IEnumerable)modelExplorer.Model;
+                var elementType = GetElementType(enumerableModel.GetType());
+                var elementMetadata = _modelMetadataProvider.GetMetadataForType(elementType);
+                validators = GetValidators(validationContext.ModelValidationContext.ValidatorProvider, elementMetadata);
+            }
+
+            foreach (var childNode in validationContext.ValidationNode.ChildNodes)
+            {
+                var childModelExplorer = childNode.ModelMetadata.MetadataKind == Metadata.ModelMetadataKind.Type ?
+                    _modelMetadataProvider.GetModelExplorerForType(childNode.ModelMetadata.ModelType, childNode.Model) :
+                    modelExplorer.GetExplorerForProperty(childNode.ModelMetadata.PropertyName);
+
                 var propertyValidationContext = new ValidationContext()
                 {
                     ModelValidationContext = ModelValidationContext.GetChildValidationContext(
                         validationContext.ModelValidationContext,
-                        propertyExplorer),
-                    Visited = validationContext.Visited
+                        childModelExplorer),
+                    Visited = validationContext.Visited,
+                    ValidationNode = childNode
                 };
 
-                var propertyBindingName = propertyMetadata.BinderModelName ?? propertyMetadata.PropertyName;
-                var childKey = ModelNames.CreatePropertyModelName(currentModelKey, propertyBindingName);
-
                 if (!ValidateNonVisitedNodeAndChildren(
-                    childKey,
-                    propertyValidationContext,
-                    validators: null))
+                        childNode.Key,
+                        propertyValidationContext,
+                        validators))
                 {
                     isValid = false;
                 }
@@ -200,51 +203,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             return isValid;
         }
 
-        private bool ValidateElements(string currentKey, IEnumerable model, ValidationContext validationContext)
-        {
-            var elementType = GetElementType(model.GetType());
-            var elementMetadata = _modelMetadataProvider.GetMetadataForType(elementType);
-
-            var validatorProvider = validationContext.ModelValidationContext.ValidatorProvider;
-            var validatorProviderContext = new ModelValidatorProviderContext(elementMetadata);
-            validatorProvider.GetValidators(validatorProviderContext);
-
-            var validators = validatorProviderContext.Validators;
-
-            // If there are no validators or the object is null we bail out quickly
-            // when there are large arrays of null, this will save a significant amount of processing
-            // with minimal impact to other scenarios.
-            var anyValidatorsDefined = validators.Any();
-            var index = 0;
-            var isValid = true;
-            foreach (var element in model)
-            {
-                // If the element is non null, the recursive calls might find more validators.
-                // If it's null, then a shallow validation will be performed.
-                if (element != null || anyValidatorsDefined)
-                {
-                    var elementExplorer = new ModelExplorer(_modelMetadataProvider, elementMetadata, element);
-                    var elementKey = ModelNames.CreateIndexModelName(currentKey, index);
-                    var elementValidationContext = new ValidationContext()
-                    {
-                        ModelValidationContext = ModelValidationContext.GetChildValidationContext(
-                            validationContext.ModelValidationContext,
-                            elementExplorer),
-                        Visited = validationContext.Visited
-                    };
-
-                    if (!ValidateNonVisitedNodeAndChildren(elementKey, elementValidationContext, validators))
-                    {
-                        isValid = false;
-                    }
-                }
-
-                index++;
-            }
-
-            return isValid;
-        }
-
         // Validates a single node (not including children)
         // Returns true if validation passes successfully
         private static bool ShallowValidate(
@@ -312,6 +270,54 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             return filters.Any(filter => filter.IsTypeExcluded(type));
         }
 
+        private void ExpandValidationNode(ValidationContext context, ModelExplorer modelExplorer)
+        {
+            var validationNode = context.ValidationNode;
+            if (validationNode.ChildNodes.Count != 0 ||
+                !validationNode.ValidateAllProperties ||
+                validationNode.Model == null)
+            {
+                return;
+            }
+
+            if (!modelExplorer.Metadata.IsCollectionType)
+            {
+                foreach (var property in validationNode.ModelMetadata.Properties)
+                {
+                    var propertyExplorer = modelExplorer.GetExplorerForProperty(property.PropertyName);
+                    var propertyBindingName = property.BinderModelName ?? property.PropertyName;
+                    var childKey = ModelNames.CreatePropertyModelName(validationNode.Key, propertyBindingName);
+                    var childNode = new ModelValidationNode(childKey, property, propertyExplorer.Model)
+                    {
+                        ValidateAllProperties = true
+                    };
+                    validationNode.ChildNodes.Add(childNode);
+                }
+            }
+            else
+            {
+                var enumerableModel = (IEnumerable)modelExplorer.Model;
+                var elementType = GetElementType(enumerableModel.GetType());
+                var elementMetadata = _modelMetadataProvider.GetMetadataForType(elementType);
+
+                // An integer index is incorrect in scenarios where there is a custom index provided by the user.
+                // However those scenarios are supported by createing a ModelValidationNode with the right keys.
+                var index = 0;
+                foreach (var element in enumerableModel)
+                {
+                    var elementExplorer = new ModelExplorer(_modelMetadataProvider, elementMetadata, element);
+                    var elementKey = ModelNames.CreateIndexModelName(validationNode.Key, index);
+                    var childNode = new ModelValidationNode(elementKey, elementMetadata, elementExplorer.Model)
+                    {
+                        ValidateAllProperties = true
+                    };
+
+                    validationNode.ChildNodes.Add(childNode);
+                    index++;
+                }
+            }
+        }
+
         private static Type GetElementType(Type type)
         {
             Debug.Assert(typeof(IEnumerable).GetTypeInfo().IsAssignableFrom(type.GetTypeInfo()));
@@ -337,6 +343,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             public ModelValidationContext ModelValidationContext { get; set; }
 
             public HashSet<object> Visited { get; set; }
+
+            public ModelValidationNode ValidationNode { get; set; }
         }
     }
 }

src/Microsoft.AspNet.Mvc.Core/ModelBinding/Validation/IObjectModelValidator.cs

@@ -13,6 +13,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
         /// </summary>
         /// <param name="validationContext">The <see cref="ModelValidationContext"/> associated with the current call.
         /// </param>
-        void Validate(ModelValidationContext validationContext);
+        /// <param name="validationNode">The <see cref="ModelValidationNode"/> for the model which gets validated.
+        /// </param>
+        void Validate(ModelValidationContext validationContext, ModelValidationNode validationNode);
     }
 }

src/Microsoft.AspNet.Mvc.Core/ParameterBinding/ModelBindingHelper.cs

@@ -312,8 +312,12 @@ namespace Microsoft.AspNet.Mvc
             {
                 var modelExplorer = new ModelExplorer(metadataProvider, modelMetadata, modelBindingResult.Model);
                 var modelValidationContext = new ModelValidationContext(modelBindingContext, modelExplorer);
-                modelValidationContext.RootPrefix = prefix;
-                objectModelValidator.Validate(modelValidationContext);
+                objectModelValidator.Validate(
+                    modelValidationContext,
+                    new ModelValidationNode(prefix, modelBindingContext.ModelMetadata, modelBindingResult.Model)
+                    {
+                        ValidateAllProperties = true
+                    });
                 return modelState.IsValid;
             }
 

src/Microsoft.AspNet.Mvc.WebApiCompatShim/ApiController.cs

@@ -417,13 +417,17 @@ namespace System.Web.Http
             var modelExplorer = MetadataProvider.GetModelExplorerForType(typeof(TEntity), entity);
 
             var modelValidationContext = new ModelValidationContext(
-                keyPrefix,
                 bindingSource: null,
                 validatorProvider: BindingContext.ValidatorProvider,
                 modelState: ModelState,
                 modelExplorer: modelExplorer);
 
-            ObjectValidator.Validate(modelValidationContext);
+            ObjectValidator.Validate(
+                modelValidationContext,
+                new ModelValidationNode(keyPrefix, modelExplorer.Metadata, entity)
+                {
+                    ValidateAllProperties = true
+                });
         }
 
         protected virtual void Dispose(bool disposing)

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/BinderTypeBasedModelBinderModelBinderTest.cs

@@ -51,7 +51,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             var bindingContext = GetBindingContext(typeof(Person), binderType: typeof(TrueModelBinder));
 
             var model = new Person();
-            var innerModelBinder = new TrueModelBinder();
             var serviceProvider = new ServiceCollection()
                 .AddSingleton(typeof(IModelBinder))
                 .BuildServiceProvider();
@@ -67,6 +66,9 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             var p = (Person)binderResult.Model;
             Assert.Equal(model.Age, p.Age);
             Assert.Equal(model.Name, p.Name);
+            Assert.NotNull(binderResult.ValidationNode);
+            Assert.Equal(bindingContext.ModelName, binderResult.ValidationNode.Key);
+            Assert.Same(binderResult.Model, binderResult.ValidationNode.Model);
         }
 
         [Fact]
@@ -138,7 +140,9 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
 
             public Task<ModelBindingResult> BindModelAsync(ModelBindingContext bindingContext)
             {
-                return Task.FromResult(new ModelBindingResult(_model, bindingContext.ModelName, true));
+                var validationNode =
+                    new ModelValidationNode(bindingContext.ModelName, bindingContext.ModelMetadata, _model);
+                return Task.FromResult(new ModelBindingResult(_model, bindingContext.ModelName, true, validationNode));
             }
         }
     }

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/BodyModelBinderTests.cs

@@ -50,6 +50,13 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             mockInputFormatter.Verify(v => v.ReadAsync(It.IsAny<InputFormatterContext>()), Times.Once);
             Assert.NotNull(binderResult);
             Assert.True(binderResult.IsModelSet);
+            Assert.NotNull(binderResult.ValidationNode);
+            Assert.True(binderResult.ValidationNode.ValidateAllProperties);
+            Assert.False(binderResult.ValidationNode.SuppressValidation);
+            Assert.Empty(binderResult.ValidationNode.ChildNodes);
+            Assert.Equal(binderResult.Key, binderResult.ValidationNode.Key);
+            Assert.Equal(bindingContext.ModelMetadata, binderResult.ValidationNode.ModelMetadata);
+            Assert.Same(binderResult.Model, binderResult.ValidationNode.Model);
         }
 
         [Fact]
@@ -71,6 +78,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             // Returns true because it understands the metadata type.
             Assert.NotNull(binderResult);
             Assert.False(binderResult.IsModelSet);
+            Assert.Null(binderResult.ValidationNode);
             Assert.Null(binderResult.Model);
             Assert.True(bindingContext.ModelState.ContainsKey("someName"));
         }
@@ -92,6 +100,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             // Assert
             Assert.NotNull(binderResult);
             Assert.False(binderResult.IsModelSet);
+            Assert.Null(binderResult.ValidationNode);
         }
 
         [Fact]
@@ -159,6 +168,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             // Returns true because it understands the metadata type.
             Assert.NotNull(binderResult);
             Assert.False(binderResult.IsModelSet);
+            Assert.Null(binderResult.ValidationNode);
             Assert.Null(binderResult.Model);
             Assert.True(bindingContext.ModelState.ContainsKey("someName"));
             var errorMessage = bindingContext.ModelState["someName"].Errors[0].Exception.Message;
@@ -192,6 +202,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             Assert.NotNull(binderResult);
             Assert.False(binderResult.IsModelSet);
             Assert.Null(binderResult.Model);
+            Assert.Null(binderResult.ValidationNode);
             Assert.True(bindingContext.ModelState.ContainsKey("someName"));
             var errorMessage = bindingContext.ModelState["someName"].Errors[0].ErrorMessage;
             Assert.Equal("Unsupported content type 'text/xyz'.", errorMessage);

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/CollectionModelBinderTest.cs

@@ -33,7 +33,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             var boundCollection = await binder.BindComplexCollectionFromIndexes(bindingContext, new[] { "foo", "bar", "baz" });
 
             // Assert
-            Assert.Equal(new[] { 42, 0, 200 }, boundCollection.ToArray());
+            Assert.Equal(new[] { 42, 0, 200 }, boundCollection.Model.ToArray());
+            Assert.Equal(
+                new[] { "someName[foo]", "someName[baz]" },
+                boundCollection.ValidationNode.ChildNodes.Select(o => o.Key).ToArray());
         }
 
         [Fact]
@@ -53,7 +56,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             var boundCollection = await binder.BindComplexCollectionFromIndexes(bindingContext, indexNames: null);
 
             // Assert
-            Assert.Equal(new[] { 42, 100 }, boundCollection.ToArray());
+            Assert.Equal(new[] { 42, 100 }, boundCollection.Model.ToArray());
+            Assert.Equal(
+                new[] { "someName[0]", "someName[1]" },
+                boundCollection.ValidationNode.ChildNodes.Select(o => o.Key).ToArray());
         }
 
         [Theory]
@@ -193,8 +199,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             var boundCollection = await binder.BindSimpleCollection(context, rawValue: new object[0], culture: null);
 
             // Assert
-            Assert.NotNull(boundCollection);
-            Assert.Empty(boundCollection);
+            Assert.NotNull(boundCollection.Model);
+            Assert.Empty(boundCollection.Model);
         }
 
         [Fact]
@@ -217,13 +223,14 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             // Arrange
             var culture = new CultureInfo("fr-FR");
             var bindingContext = GetModelBindingContext(new SimpleHttpValueProvider());
-
+            ModelValidationNode childValidationNode = null;
             Mock.Get<IModelBinder>(bindingContext.OperationBindingContext.ModelBinder)
                 .Setup(o => o.BindModelAsync(It.IsAny<ModelBindingContext>()))
                 .Returns((ModelBindingContext mbc) =>
                 {
                     Assert.Equal("someName", mbc.ModelName);
-                    return Task.FromResult(new ModelBindingResult(42, mbc.ModelName, true));
+                    childValidationNode = new ModelValidationNode("someName", mbc.ModelMetadata, mbc.Model);
+                    return Task.FromResult(new ModelBindingResult(42, mbc.ModelName, true, childValidationNode));
                 });
             var modelBinder = new CollectionModelBinder<int>();
 
@@ -231,7 +238,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             var boundCollection = await modelBinder.BindSimpleCollection(bindingContext, new int[1], culture);
 
             // Assert
-            Assert.Equal(new[] { 42 }, boundCollection.ToArray());
+            Assert.Equal(new[] { 42 }, boundCollection.Model.ToArray());
+            Assert.Equal(new[] { childValidationNode }, boundCollection.ValidationNode.ChildNodes.ToArray());
         }
 
         private static ModelBindingContext GetModelBindingContext(
@@ -267,7 +275,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
                     if (value != null)
                     {
                         var model = value.ConvertTo(mbc.ModelType);
-                        return new ModelBindingResult(model, mbc.ModelName, true);
+                        var modelValidationNode = new ModelValidationNode(mbc.ModelName, mbc.ModelMetadata, model);
+                        return new ModelBindingResult(model, mbc.ModelName, true, modelValidationNode);
                     }
 
                     return null;

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/CompositeModelBinderTest.cs

@@ -374,6 +374,26 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             var model = Assert.IsType<SimplePropertiesModel>(result.Model);
             Assert.Equal("firstName-value", model.FirstName);
             Assert.Equal("lastName-value", model.LastName);
+
+            Assert.NotNull(result.ValidationNode);
+            Assert.Equal(2, result.ValidationNode.ChildNodes.Count);
+            Assert.Equal("", result.ValidationNode.Key);
+            Assert.Equal(bindingContext.ModelMetadata, result.ValidationNode.ModelMetadata);
+            model = Assert.IsType<SimplePropertiesModel>(result.ValidationNode.Model);
+            Assert.Equal("firstName-value", model.FirstName);
+            Assert.Equal("lastName-value", model.LastName);
+
+            Assert.Equal(2, result.ValidationNode.ChildNodes.Count);
+
+            var validationNode = result.ValidationNode.ChildNodes[0];
+            Assert.Equal("FirstName", validationNode.Key);
+            Assert.Equal("firstName-value", validationNode.Model);
+            Assert.Empty(validationNode.ChildNodes);
+
+            validationNode = result.ValidationNode.ChildNodes[1];
+            Assert.Equal("LastName", validationNode.Key);
+            Assert.Equal("lastName-value", validationNode.Model);
+            Assert.Empty(validationNode.ChildNodes);
         }
 
         [Fact]
@@ -414,6 +434,79 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             Assert.Equal(new byte[] { 227, 233, 133, 121, 58, 119, 180, 241 }, model.Resume);
         }
 
+        [Fact]
+        public async Task BindModel_DoesNotAddAValidationNode_IfModelIsNotSet()
+        {
+            // Arrange
+            var valueProvider = new SimpleHttpValueProvider();
+            var mockBinder = new Mock<IModelBinder>();
+            mockBinder
+                .Setup(o => o.BindModelAsync(It.IsAny<ModelBindingContext>()))
+                .Returns(
+                    delegate (ModelBindingContext context)
+                    {
+                        return Task.FromResult(
+                            new ModelBindingResult(model: 42, key: "someName", isModelSet: false));
+                    });
+            var binder = CreateCompositeBinder(mockBinder.Object);
+            var bindingContext = CreateBindingContext(binder, valueProvider, typeof(SimplePropertiesModel));
+
+            // Act
+            var result = await binder.BindModelAsync(bindingContext);
+
+            // Assert
+            // The result is null because of issue #2473
+            Assert.Null(result);
+        }
+
+        [Fact]
+        public async Task BindModel_DoesNotAddAValidationNode_IfModelBindingResultIsNull()
+        {
+            // Arrange
+            var mockBinder = new Mock<IModelBinder>();
+            mockBinder
+                .Setup(o => o.BindModelAsync(It.IsAny<ModelBindingContext>()))
+                .Returns(Task.FromResult<ModelBindingResult>(null));
+            var binder = CreateCompositeBinder(mockBinder.Object);
+            var valueProvider = new SimpleHttpValueProvider();
+            var bindingContext = CreateBindingContext(binder, valueProvider, typeof(SimplePropertiesModel));
+
+            // Act
+            var result = await binder.BindModelAsync(bindingContext);
+
+            // Assert
+            Assert.Null(result);
+        }
+
+        [Fact]
+        public async Task BindModel_UsesTheValidationNodeOnModelBindingResult_IfPresent()
+        {
+            // Arrange
+            var valueProvider = new SimpleHttpValueProvider();
+            ModelValidationNode validationNode = null;
+
+            var mockBinder = new Mock<IModelBinder>();
+            mockBinder
+                .Setup(o => o.BindModelAsync(It.IsAny<ModelBindingContext>()))
+                .Returns(
+                    delegate (ModelBindingContext context)
+                    {
+                        validationNode = new ModelValidationNode("someName", context.ModelMetadata, 42);
+                        return Task.FromResult(
+                            new ModelBindingResult(42, "someName", isModelSet: true, validationNode: validationNode));
+                    });
+            var binder = CreateCompositeBinder(mockBinder.Object);
+            var bindingContext = CreateBindingContext(binder, valueProvider, typeof(SimplePropertiesModel));
+
+            // Act
+            var result = await binder.BindModelAsync(bindingContext);
+
+            // Assert
+            Assert.NotNull(result);
+            Assert.True(result.IsModelSet);
+            Assert.Same(validationNode, result.ValidationNode);
+        }
+
         private static ModelBindingContext CreateBindingContext(IModelBinder binder,
                                                                 IValueProvider valueProvider,
                                                                 Type type,

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/KeyValuePairModelBinderTest.cs

@@ -31,6 +31,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             Assert.NotNull(result);
             Assert.Null(result.Model);
             Assert.False(bindingContext.ModelState.IsValid);
+            Assert.Null(result.ValidationNode);
             Assert.Equal("someName", bindingContext.ModelName);
             var error = Assert.Single(bindingContext.ModelState["someName.Key"].Errors);
             Assert.Equal("A value is required.", error.ErrorMessage);
@@ -53,6 +54,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             Assert.NotNull(result);
             Assert.Null(result.Model);
             Assert.False(bindingContext.ModelState.IsValid);
+            Assert.Null(result.ValidationNode);
             Assert.Equal("someName", bindingContext.ModelName);
             Assert.Equal(bindingContext.ModelState["someName.Value"].Errors.First().ErrorMessage, "A value is required.");
         }
@@ -97,17 +99,31 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             // Assert
             Assert.NotNull(result);
             Assert.Equal(new KeyValuePair<int, string>(42, "some-value"), result.Model);
+            Assert.NotNull(result.ValidationNode);
+            Assert.Equal(new KeyValuePair<int, string>(42, "some-value"), result.ValidationNode.Model);
+            Assert.Equal("someName", result.ValidationNode.Key);
+
+            var validationNode = result.ValidationNode.ChildNodes[0];
+            Assert.Equal("someName.Key", validationNode.Key);
+            Assert.Equal(42, validationNode.Model);
+            Assert.Empty(validationNode.ChildNodes);
+
+            validationNode = result.ValidationNode.ChildNodes[1];
+            Assert.Equal("someName.Value", validationNode.Key);
+            Assert.Equal("some-value", validationNode.Model);
+            Assert.Empty(validationNode.ChildNodes);
         }
 
         [Fact]
         public async Task TryBindStrongModel_BinderExists_BinderReturnsCorrectlyTypedObject_ReturnsTrue()
         {
             // Arrange
-            ModelBindingContext bindingContext = GetBindingContext(new SimpleHttpValueProvider());
+            var bindingContext = GetBindingContext(new SimpleHttpValueProvider());
             var binder = new KeyValuePairModelBinder<int, string>();
+            var modelValidationNodeList = new List<ModelValidationNode>();
 
             // Act
-            var result = await binder.TryBindStrongModel<int>(bindingContext, "key");
+            var result = await binder.TryBindStrongModel<int>(bindingContext, "key", modelValidationNodeList);
 
             // Assert
             Assert.True(result.IsModelSet);
@@ -131,9 +147,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
 
 
             var binder = new KeyValuePairModelBinder<int, string>();
+            var modelValidationNodeList = new List<ModelValidationNode>();
 
             // Act
-            var result = await binder.TryBindStrongModel<int>(bindingContext, "key");
+            var result = await binder.TryBindStrongModel<int>(bindingContext, "key", modelValidationNodeList);
 
             // Assert
             Assert.True(result.IsModelSet);

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/MutableObjectModelBinderTest.cs

@@ -776,11 +776,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 "John Doe",
                 isModelSet: true,
                 key: "");
-
+            var modelValidationNode = new ModelValidationNode(string.Empty, containerMetadata, model);
             var testableBinder = new TestableMutableObjectModelBinder();
 
             // Act
-            testableBinder.ProcessDto(bindingContext, dto);
+            testableBinder.ProcessDto(bindingContext, dto, modelValidationNode);
 
             // Assert
             var modelStateDictionary = bindingContext.ModelState;
@@ -827,10 +827,11 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 isModelSet: true,
                 key: "");
 
+            var modelValidationNode = new ModelValidationNode(string.Empty, containerMetadata, model);
             var testableBinder = new TestableMutableObjectModelBinder();
 
             // Act
-            testableBinder.ProcessDto(bindingContext, dto);
+            testableBinder.ProcessDto(bindingContext, dto, modelValidationNode);
 
             // Assert
             var modelStateDictionary = bindingContext.ModelState;
@@ -888,8 +889,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 isModelSet: true,
                 key: "theModel.Age");
 
+            var modelValidationNode = new ModelValidationNode(string.Empty, containerMetadata, model);
+
             // Act
-            testableBinder.ProcessDto(bindingContext, dto);
+            testableBinder.ProcessDto(bindingContext, dto, modelValidationNode);
 
             // Assert
             var modelStateDictionary = bindingContext.ModelState;
@@ -920,9 +923,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             // Set no properties though Age (a non-Nullable struct) and City (a class) properties are required.
             var dto = new ComplexModelDto(containerMetadata, containerMetadata.Properties);
             var testableBinder = new TestableMutableObjectModelBinder();
+            var modelValidationNode = new ModelValidationNode(string.Empty, containerMetadata, model);
 
             // Act
-            testableBinder.ProcessDto(bindingContext, dto);
+            testableBinder.ProcessDto(bindingContext, dto, modelValidationNode);
 
             // Assert
             var modelStateDictionary = bindingContext.ModelState;
@@ -973,9 +977,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 null,
                 isModelSet: true,
                 key: "theModel.City");
+            var modelValidationNode = new ModelValidationNode(string.Empty, containerMetadata, model);
 
             // Act
-            testableBinder.ProcessDto(bindingContext, dto);
+            testableBinder.ProcessDto(bindingContext, dto, modelValidationNode);
 
             // Assert
             var modelStateDictionary = bindingContext.ModelState;
@@ -1004,9 +1009,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
             // Set no properties though ValueTypeRequired (a non-Nullable struct) property is required.
             var dto = new ComplexModelDto(containerMetadata, containerMetadata.Properties);
             var testableBinder = new TestableMutableObjectModelBinder();
+            var modelValidationNode = new ModelValidationNode(string.Empty, containerMetadata, model);
 
             // Act
-            testableBinder.ProcessDto(bindingContext, dto);
+            testableBinder.ProcessDto(bindingContext, dto, modelValidationNode);
 
             // Assert
             var modelStateDictionary = bindingContext.ModelState;
@@ -1074,9 +1080,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 model: null,
                 isModelSet: isModelSet,
                 key: "theModel." + nameof(Person.ValueTypeRequiredWithDefaultValue));
+            var modelValidationNode = new ModelValidationNode(string.Empty, containerMetadata, model);
 
             // Act
-            testableBinder.ProcessDto(bindingContext, dto);
+            testableBinder.ProcessDto(bindingContext, dto, modelValidationNode);
 
             // Assert
             Assert.False(modelStateDictionary.IsValid);
@@ -1149,9 +1156,10 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 model: null,
                 isModelSet: false,
                 key: "theModel." + nameof(Person.PropertyWithDefaultValue));
+            var modelValidationNode = new ModelValidationNode(string.Empty, containerMetadata, model);
 
             // Act
-            testableBinder.ProcessDto(bindingContext, dto);
+            testableBinder.ProcessDto(bindingContext, dto, modelValidationNode);
 
             // Assert
             Assert.True(modelStateDictionary.IsValid);
@@ -1191,17 +1199,30 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
             var dobProperty = dto.PropertyMetadata.Single(o => o.PropertyName == "DateOfBirth");
             dto.Results[dobProperty] = null;
+            var modelValidationNode = new ModelValidationNode(string.Empty, containerMetadata, model);
 
             var testableBinder = new TestableMutableObjectModelBinder();
 
             // Act
-            testableBinder.ProcessDto(bindingContext, dto);
+            testableBinder.ProcessDto(bindingContext, dto, modelValidationNode);
 
             // Assert
             Assert.Equal("John", model.FirstName);
             Assert.Equal("Doe", model.LastName);
             Assert.Equal(dob, model.DateOfBirth);
             Assert.True(bindingContext.ModelState.IsValid);
+
+            // Ensure that we add child nodes for all the nodes which have a result (irrespective of if they 
+            // are bound or not).
+            Assert.Equal(2, modelValidationNode.ChildNodes.Count());
+
+            var validationNode = modelValidationNode.ChildNodes[0];
+            Assert.Equal("", validationNode.Key);
+            Assert.Equal("John", validationNode.Model);
+
+            validationNode = modelValidationNode.ChildNodes[1];
+            Assert.Equal("", validationNode.Key);
+            Assert.Equal("Doe", validationNode.Model);
         }
 
         [Fact]

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/Validation/DataAnnotationsModelValidatorTest.cs

@@ -231,7 +231,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
         private static ModelValidationContext CreateValidationContext(ModelExplorer modelExplorer)
         {
             return new ModelValidationContext(
-                rootPrefix: null,
                 bindingSource: null,
                 modelState: null,
                 validatorProvider: null,

test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/Validation/DefaultObjectValidatorTests.cs

@@ -212,9 +212,14 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var context = GetModelValidationContext(model, type);
 
             var validator = new DefaultObjectValidator(context.ExcludeFilters, context.ModelMetadataProvider);
+            var topLevelValidationNode =
+                new ModelValidationNode(string.Empty, context.ModelValidationContext.ModelExplorer.Metadata, model)
+                {
+                    ValidateAllProperties = true
+                };
 
             // Act
-            validator.Validate(context.ModelValidationContext);
+            validator.Validate(context.ModelValidationContext, topLevelValidationNode);
 
             // Assert
             var actualErrors = new Dictionary<string, string>();
@@ -240,6 +245,14 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
         {
             // Arrange
             var testValidationContext = GetModelValidationContext(new Uri("/api/values", UriKind.Relative), typeof(Uri));
+            var topLevelValidationNode =
+                new ModelValidationNode(
+                    string.Empty,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Metadata,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Model)
+                {
+                    ValidateAllProperties = true
+                };
 
             // Act & Assert
             Assert.Throws(
@@ -249,7 +262,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
                     new DefaultObjectValidator(
                         testValidationContext.ExcludeFilters,
                         testValidationContext.ModelMetadataProvider)
-                        .Validate(testValidationContext.ModelValidationContext);
+                        .Validate(testValidationContext.ModelValidationContext, topLevelValidationNode);
                 });
         }
 
@@ -265,7 +278,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
                 yield return new object[] { new Dictionary<string, Uri> {
                     { "values",  new Uri("/api/values", UriKind.Relative) },
                     { "hello",  new Uri("/api/hello", UriKind.Relative) }
-                }, typeof(Uri), new List<Type>() { typeof(Uri) } };
+                }, typeof(Dictionary<string, Uri>), new List<Type>() { typeof(Uri) } };
             }
         }
 
@@ -276,13 +289,21 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             object input, Type type, List<Type> excludedTypes)
         {
             // Arrange
-            var testValidationContext = GetModelValidationContext(input, type, string.Empty, excludedTypes);
+            var testValidationContext = GetModelValidationContext(input, type, excludedTypes);
+            var topLevelValidationNode =
+                new ModelValidationNode(
+                    string.Empty,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Metadata,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Model)
+                {
+                    ValidateAllProperties = true
+                };
 
             // Act & Assert (does not throw)
             new DefaultObjectValidator(
                 testValidationContext.ExcludeFilters,
                 testValidationContext.ModelMetadataProvider)
-                .Validate(testValidationContext.ModelValidationContext);
+                .Validate(testValidationContext.ModelValidationContext, topLevelValidationNode);
             Assert.True(testValidationContext.ModelValidationContext.ModelState.IsValid);
         }
 
@@ -294,6 +315,14 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var testValidationContext = GetModelValidationContext(
                 new Uri("/api/values", UriKind.Relative), typeof(Uri));
             var validationContext = testValidationContext.ModelValidationContext;
+            var topLevelValidationNode =
+                new ModelValidationNode(
+                    string.Empty,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Metadata,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Model)
+                {
+                    ValidateAllProperties = true
+                };
 
             // Act & Assert
             Assert.Throws<InvalidOperationException>(
@@ -302,7 +331,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
                     new DefaultObjectValidator(
                         testValidationContext.ExcludeFilters,
                         testValidationContext.ModelMetadataProvider)
-                        .Validate(validationContext);
+                        .Validate(validationContext, topLevelValidationNode);
                 });
             Assert.True(validationContext.ModelState.IsValid);
         }
@@ -315,12 +344,20 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var model = new Address() { Street = "Microsoft Way" };
             var testValidationContext = GetModelValidationContext(model, model.GetType());
             var validationContext = testValidationContext.ModelValidationContext;
+            var topLevelValidationNode =
+                new ModelValidationNode(
+                    string.Empty,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Metadata,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Model)
+                {
+                    ValidateAllProperties = true
+                };
 
             // Act (does not throw)
             new DefaultObjectValidator(
                 testValidationContext.ExcludeFilters,
                 testValidationContext.ModelMetadataProvider)
-                .Validate(validationContext);
+                .Validate(validationContext, topLevelValidationNode);
 
             // Assert
             Assert.Contains("Street", validationContext.ModelState.Keys);
@@ -340,12 +377,20 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
                     new TypeThatOverridesEquals { Funny = "hehe" }
                 };
             var testValidationContext = GetModelValidationContext(instance, typeof(TypeThatOverridesEquals[]));
+            var topLevelValidationNode =
+                new ModelValidationNode(
+                    string.Empty,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Metadata,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Model)
+                {
+                    ValidateAllProperties = true
+                };
 
             // Act & Assert (does not throw)
             new DefaultObjectValidator(
                 testValidationContext.ExcludeFilters,
                 testValidationContext.ModelMetadataProvider)
-                .Validate(testValidationContext.ModelValidationContext);
+                .Validate(testValidationContext.ModelValidationContext, topLevelValidationNode);
         }
 
         [Fact]
@@ -361,7 +406,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var testValidationContext = GetModelValidationContext(
                 user,
                 typeof(User),
-                "user",
                 new List<Type> { typeof(string) });
 
             var validationContext = testValidationContext.ModelValidationContext;
@@ -370,9 +414,17 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var validator = new DefaultObjectValidator(
                 testValidationContext.ExcludeFilters,
                 testValidationContext.ModelMetadataProvider);
+            var topLevelValidationNode =
+                new ModelValidationNode(
+                    "user",
+                    testValidationContext.ModelValidationContext.ModelExplorer.Metadata,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Model)
+                {
+                    ValidateAllProperties = true
+                };
 
             // Act
-            validator.Validate(validationContext);
+            validator.Validate(validationContext, topLevelValidationNode);
 
             // Assert
             Assert.Equal(new[] { "key1", "user.Password", "", "user.ConfirmPassword" },
@@ -380,7 +432,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var modelState = validationContext.ModelState["user.ConfirmPassword"];
             Assert.Empty(modelState.Errors);
             Assert.Equal(modelState.ValidationState, ModelValidationState.Skipped);
-            
+
             var error = Assert.Single(validationContext.ModelState[""].Errors);
             Assert.IsType<TooManyModelErrorsException>(error.Exception);
         }
@@ -398,15 +450,22 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var testValidationContext = GetModelValidationContext(
                 user,
                 typeof(User),
-                "user",
                 new List<Type> { typeof(User) });
             var validationContext = testValidationContext.ModelValidationContext;
             var validator = new DefaultObjectValidator(
                 testValidationContext.ExcludeFilters,
                 testValidationContext.ModelMetadataProvider);
+            var topLevelValidationNode =
+                new ModelValidationNode(
+                    "user",
+                    testValidationContext.ModelValidationContext.ModelExplorer.Metadata,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Model)
+                {
+                    ValidateAllProperties = true
+                };
 
             // Act
-            validator.Validate(validationContext);
+            validator.Validate(validationContext, topLevelValidationNode);
 
             // Assert
             Assert.False(validationContext.ModelState.ContainsKey("user.Password"));
@@ -429,7 +488,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var testValidationContext = GetModelValidationContext(
                 user,
                 typeof(User),
-                "user",
                 new List<Type> { typeof(User) });
             var validationContext = testValidationContext.ModelValidationContext;
 
@@ -440,9 +498,17 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var validator = new DefaultObjectValidator(
                 testValidationContext.ExcludeFilters,
                 testValidationContext.ModelMetadataProvider);
+            var topLevelValidationNode =
+                new ModelValidationNode(
+                    "user",
+                    testValidationContext.ModelValidationContext.ModelExplorer.Metadata,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Model)
+                {
+                    ValidateAllProperties = true
+                };
 
             // Act
-            validator.Validate(validationContext);
+            validator.Validate(validationContext, topLevelValidationNode);
 
             // Assert
             var modelState = validationContext.ModelState["user.Password"];
@@ -455,21 +521,36 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
         }
 
         [Fact]
-        public void NonRequestBoundModel_MarkedAsSkipped()
+        public void Validate_IfSuppressIsSet_MarkedAsSkipped()
         {
             // Arrange
             var testValidationContext = GetModelValidationContext(
                 new TestServiceProvider(),
-                typeof(TestServiceProvider),
-                "serviceProvider");
+                typeof(TestServiceProvider));
 
             var validationContext = testValidationContext.ModelValidationContext;
             var validator = new DefaultObjectValidator(
                 testValidationContext.ExcludeFilters, 
                 testValidationContext.ModelMetadataProvider);
+            var modelExplorer = testValidationContext.ModelValidationContext.ModelExplorer;
+            var topLevelValidationNode = new ModelValidationNode(
+                "serviceProvider",
+                modelExplorer.Metadata,
+                modelExplorer.Model);
+
+            var propertyExplorer = modelExplorer.GetExplorerForProperty("TestService");
+            var childNode = new ModelValidationNode(
+                "serviceProvider.TestService",
+                propertyExplorer.Metadata,
+                propertyExplorer.Model)
+            {
+                SuppressValidation = true
+            };
+
+            topLevelValidationNode.ChildNodes.Add(childNode);
 
             // Act
-            validator.Validate(validationContext);
+            validator.Validate(validationContext, topLevelValidationNode);
 
             // Assert
             Assert.True(validationContext.ModelState.IsValid);
@@ -496,7 +577,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var testValidationContext = GetModelValidationContext(
                 model,
                 type,
-                "items",
                 excludedTypes: null,
                 modelStateDictionary: modelStateDictionary);
 
@@ -509,9 +589,17 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var validator = new DefaultObjectValidator(
                 testValidationContext.ExcludeFilters,
                 testValidationContext.ModelMetadataProvider);
+            var topLevelValidationNode =
+                new ModelValidationNode(
+                    "items",
+                    testValidationContext.ModelValidationContext.ModelExplorer.Metadata,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Model)
+                {
+                    ValidateAllProperties = true
+                };
 
             // Act
-            validator.Validate(validationContext);
+            validator.Validate(validationContext, topLevelValidationNode);
 
             // Assert
             Assert.True(validationContext.ModelState.IsValid);
@@ -538,7 +626,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             var testValidationContext = GetModelValidationContext(
                 model,
                 typeof(Dictionary<string, string>),
-                "items",
                 excludedTypes: null,
                 modelStateDictionary: modelStateDictionary);
 
@@ -552,8 +639,17 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
                 testValidationContext.ExcludeFilters,
                 testValidationContext.ModelMetadataProvider);
 
+            var topLevelValidationNode =
+                new ModelValidationNode(
+                    "items",
+                    testValidationContext.ModelValidationContext.ModelExplorer.Metadata,
+                    testValidationContext.ModelValidationContext.ModelExplorer.Model)
+                {
+                    ValidateAllProperties = true
+                };
+
             // Act
-            validator.Validate(validationContext);
+            validator.Validate(validationContext, topLevelValidationNode);
 
             // Assert
             Assert.True(validationContext.ModelState.IsValid);
@@ -569,19 +665,88 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             Assert.Equal(modelState.ValidationState, ModelValidationState.Skipped);
         }
 
-        private TestModelValidationContext GetModelValidationContext(
-            object model,
-            Type type,
-            string key = "",
-            List<Type> excludedTypes = null)
+        [Fact]
+        public void Validator_IfValidateAllPropertiesIsNotSet_DoesNotAutoExpand()
         {
-            return GetModelValidationContext(model, type, key, excludedTypes, new ModelStateDictionary());
+            // Arrange
+            var testValidationContext = GetModelValidationContext(
+                LonelyPerson,
+                typeof(Person));
+
+            var validationContext = testValidationContext.ModelValidationContext;
+            var validator = new DefaultObjectValidator(
+                testValidationContext.ExcludeFilters,
+                testValidationContext.ModelMetadataProvider);
+            var modelExplorer = testValidationContext.ModelValidationContext.ModelExplorer;
+
+            // No ChildNode added
+            var topLevelValidationNode = new ModelValidationNode(
+                "person",
+                modelExplorer.Metadata,
+                modelExplorer.Model);
+
+            // Act
+            validator.Validate(validationContext, topLevelValidationNode);
+
+            // Assert
+            Assert.True(validationContext.ModelState.IsValid);
+            var key = Assert.Single(validationContext.ModelState.Keys);
+            Assert.Equal("person", key);
+        }
+
+        [Fact]
+        public void Validator_IfValidateAllPropertiesSet_WithChildNodes_DoesNotAutoExpand()
+        {
+            // Arrange
+            var testValidationContext = GetModelValidationContext(
+                LonelyPerson,
+                typeof(Person));
+
+            var validationContext = testValidationContext.ModelValidationContext;
+            var validator = new DefaultObjectValidator(
+                testValidationContext.ExcludeFilters,
+                testValidationContext.ModelMetadataProvider);
+            var modelExplorer = testValidationContext.ModelValidationContext.ModelExplorer;
+
+            var topLevelValidationNode = new ModelValidationNode(
+                "person",
+                modelExplorer.Metadata,
+                modelExplorer.Model)
+            {
+                ValidateAllProperties = true
+            };
+
+            var propertyExplorer = modelExplorer.GetExplorerForProperty("Profession");
+            var childNode = new ModelValidationNode(
+                "person.Profession",
+                propertyExplorer.Metadata,
+                propertyExplorer.Model);
+
+            topLevelValidationNode.ChildNodes.Add(childNode);
+
+            // Act
+            validator.Validate(validationContext, topLevelValidationNode);
+
+            // Assert
+            var modelState = validationContext.ModelState;
+            Assert.False(modelState.IsValid);
+
+            // Since the model is invalid at property level there is no entry in the model state for top level node.
+            Assert.Single(modelState.Keys, k => k == "person.Profession");
+            Assert.Equal(1, modelState.Count);
+        }
+
+        private TestModelValidationContext GetModelValidationContext(
+            object model,
+            Type type,
+            List<Type> excludedTypes = null)
+        {
+            return GetModelValidationContext(model, type, excludedTypes, new ModelStateDictionary());
         }
 
         private TestModelValidationContext GetModelValidationContext(
             object model,
             Type type,
-            string key,
             List<Type> excludedTypes,
             ModelStateDictionary modelStateDictionary)
         {
@@ -603,7 +768,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Validation
             return new TestModelValidationContext
             {
                 ModelValidationContext = new ModelValidationContext(
-                    key,
                     null,
                     TestModelValidatorProvider.CreateDefaultProvider(),
                     modelStateDictionary,

test/Microsoft.AspNet.Mvc.Core.Test/ParameterBinding/ControllerActionArgumentBinderTests.cs

@@ -154,7 +154,7 @@ namespace Microsoft.AspNet.Mvc.Core.Test
 
             var mockValidatorProvider = new Mock<IObjectModelValidator>(MockBehavior.Strict);
             mockValidatorProvider
-                .Setup(o => o.Validate(It.IsAny<ModelValidationContext>()))
+                .Setup(o => o.Validate(It.IsAny<ModelValidationContext>(), It.IsAny<ModelValidationNode>()))
                 .Verifiable();
             var argumentBinder = GetArgumentBinder(mockValidatorProvider.Object);
 
@@ -164,7 +164,7 @@ namespace Microsoft.AspNet.Mvc.Core.Test
 
             // Assert
             mockValidatorProvider.Verify(
-                o => o.Validate(It.IsAny<ModelValidationContext>()), Times.Once());
+                o => o.Validate(It.IsAny<ModelValidationContext>(), It.IsAny<ModelValidationNode>()), Times.Once());
         }
 
         [Fact]
@@ -197,8 +197,9 @@ namespace Microsoft.AspNet.Mvc.Core.Test
             };
 
             var mockValidatorProvider = new Mock<IObjectModelValidator>(MockBehavior.Strict);
-            mockValidatorProvider.Setup(o => o.Validate(It.IsAny<ModelValidationContext>()))
-                                 .Verifiable();
+            mockValidatorProvider
+                .Setup(o => o.Validate(It.IsAny<ModelValidationContext>(), It.IsAny<ModelValidationNode>()))
+                .Verifiable();
             var argumentBinder = GetArgumentBinder(mockValidatorProvider.Object);
 
             // Act
@@ -206,7 +207,9 @@ namespace Microsoft.AspNet.Mvc.Core.Test
                 .BindActionArgumentsAsync(actionContext, actionBindingContext, new TestController());
 
             // Assert
-            mockValidatorProvider.Verify(o => o.Validate(It.IsAny<ModelValidationContext>()), Times.Never());
+            mockValidatorProvider.Verify(
+                o => o.Validate(It.IsAny<ModelValidationContext>(), It.IsAny<ModelValidationNode>()),
+                Times.Never());
         }
 
         [Fact]
@@ -226,7 +229,7 @@ namespace Microsoft.AspNet.Mvc.Core.Test
 
             var mockValidatorProvider = new Mock<IObjectModelValidator>(MockBehavior.Strict);
             mockValidatorProvider
-                .Setup(o => o.Validate(It.IsAny<ModelValidationContext>()))
+                .Setup(o => o.Validate(It.IsAny<ModelValidationContext>(), It.IsAny<ModelValidationNode>()))
                 .Verifiable();
             var argumentBinder = GetArgumentBinder(mockValidatorProvider.Object);
 
@@ -236,7 +239,7 @@ namespace Microsoft.AspNet.Mvc.Core.Test
 
             // Assert
             mockValidatorProvider.Verify(
-                o => o.Validate(It.IsAny<ModelValidationContext>()), Times.Once());
+                o => o.Validate(It.IsAny<ModelValidationContext>(), It.IsAny<ModelValidationNode>()), Times.Once());
         }
 
         [Fact]
@@ -268,8 +271,10 @@ namespace Microsoft.AspNet.Mvc.Core.Test
             };
 
             var mockValidatorProvider = new Mock<IObjectModelValidator>(MockBehavior.Strict);
-            mockValidatorProvider.Setup(o => o.Validate(It.IsAny<ModelValidationContext>()))
-                                 .Verifiable();
+            mockValidatorProvider
+                .Setup(o => o.Validate(It.IsAny<ModelValidationContext>(), It.IsAny<ModelValidationNode>()))
+                .Verifiable();
+
             var argumentBinder = GetArgumentBinder(mockValidatorProvider.Object);
 
             // Act
@@ -277,7 +282,9 @@ namespace Microsoft.AspNet.Mvc.Core.Test
                 .BindActionArgumentsAsync(actionContext, actionBindingContext, new TestController());
 
             // Assert
-            mockValidatorProvider.Verify(o => o.Validate(It.IsAny<ModelValidationContext>()), Times.Never());
+            mockValidatorProvider.Verify(
+                o => o.Validate(It.IsAny<ModelValidationContext>(), It.IsAny<ModelValidationNode>()),
+                Times.Never());
         }
 
         [Fact]
@@ -596,7 +603,8 @@ namespace Microsoft.AspNet.Mvc.Core.Test
             if (validator == null)
             {
                 var mockValidator = new Mock<IObjectModelValidator>(MockBehavior.Strict);
-                mockValidator.Setup(o => o.Validate(It.IsAny<ModelValidationContext>()));
+                mockValidator.Setup(
+                    o => o.Validate(It.IsAny<ModelValidationContext>(), It.IsAny<ModelValidationNode>()));
                 validator = mockValidator.Object;
             }
 

test/Microsoft.AspNet.Mvc.IntegrationTests/BinderTypeBasedModelBinderIntegrationTest.cs

@@ -281,7 +281,12 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
         {
             public Task<ModelBindingResult> BindModelAsync(ModelBindingContext bindingContext)
             {
-                return Task.FromResult(new ModelBindingResult("Success", bindingContext.ModelName, true));
+                var model = "Success";
+                var modelValidationNode = new ModelValidationNode(
+                    bindingContext.ModelName,
+                    bindingContext.ModelMetadata,
+                    model);
+                return Task.FromResult(new ModelBindingResult(model, bindingContext.ModelName, true, modelValidationNode));
             }
         }
 

test/Microsoft.AspNet.Mvc.IntegrationTests/CollectionModelBinderIntegrationTest.cs

@@ -2,8 +2,11 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Collections.Generic;
+using System.IO;
+using System.Text;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Http;
+using Microsoft.AspNet.Http.Internal;
 using Microsoft.AspNet.Mvc.ModelBinding;
 using Xunit;
 
@@ -536,5 +539,63 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
             Assert.Equal(0, modelState.ErrorCount);
             Assert.True(modelState.IsValid);
         }
+
+        private class Person4
+        {
+            public IList<Address4> Addresses { get; set; }
+        }
+
+        private class Address4
+        {
+            public int Zip { get; set; }
+
+            public string Street { get; set; }
+        }
+
+        [Fact(Skip = "Extra ModelState key because of #2446")]
+        public async Task CollectionModelBinder_UsesCustomIndexes()
+        {
+            // Arrange
+            var argumentBinder = ModelBindingTestHelper.GetArgumentBinder();
+            var parameter = new ParameterDescriptor()
+            {
+                Name = "parameter",
+                ParameterType = typeof(Person4)
+            };
+
+            var operationContext = ModelBindingTestHelper.GetOperationBindingContext(request =>
+            {
+                var formCollection = new FormCollection(new Dictionary<string, string[]>()
+                {
+                    { "Addresses.index", new [] { "Key1", "Key2" } },
+                    { "Addresses[Key1].Street", new [] { "Street1" } },
+                    { "Addresses[Key2].Street", new [] { "Street2" } },
+                });
+
+                request.Form = formCollection;
+                request.ContentType = "application/x-www-form-urlencoded";
+            });
+
+            var modelState = new ModelStateDictionary();
+
+            // Act
+            var modelBindingResult = await argumentBinder.BindModelAsync(parameter, modelState, operationContext);
+
+            // Assert
+            Assert.NotNull(modelBindingResult);
+            Assert.True(modelBindingResult.IsModelSet);
+            Assert.IsType<Person4>(modelBindingResult.Model);
+
+            Assert.Equal(2, modelState.Count);
+            Assert.Equal(0, modelState.ErrorCount);
+            Assert.True(modelState.IsValid);
+            var entry = Assert.Single(modelState, kvp => kvp.Key == "Addresses[Key1].Street").Value;
+            Assert.Equal("Street1", entry.Value.AttemptedValue);
+            Assert.Equal("Street1", entry.Value.RawValue);
+
+            entry = Assert.Single(modelState, kvp => kvp.Key == "Addresses[Key2].Street").Value;
+            Assert.Equal("Street2", entry.Value.AttemptedValue);
+            Assert.Equal("Street2", entry.Value.RawValue);
+        }
     }
 }