Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/class/System.Web.Mvc3/Mvc/HttpFileCollectionValueProvider.cs

@@ -0,0 +1,40 @@
+namespace System.Web.Mvc {
+    using System;
+    using System.Collections.Generic;
+    using System.Globalization;
+    using System.Linq;
+
+    public sealed class HttpFileCollectionValueProvider : DictionaryValueProvider<HttpPostedFileBase[]> {
+
+        private static readonly Dictionary<string, HttpPostedFileBase[]> _emptyDictionary = new Dictionary<string, HttpPostedFileBase[]>();
+
+        public HttpFileCollectionValueProvider(ControllerContext controllerContext)
+            : base(GetHttpPostedFileDictionary(controllerContext), CultureInfo.InvariantCulture) {
+        }
+
+        private static Dictionary<string, HttpPostedFileBase[]> GetHttpPostedFileDictionary(ControllerContext controllerContext) {
+            HttpFileCollectionBase files = controllerContext.HttpContext.Request.Files;
+
+            // fast-track common case of no files
+            if (files.Count == 0) {
+                return _emptyDictionary;
+            }
+
+            // build up the 1:many file mapping
+            List<KeyValuePair<string, HttpPostedFileBase>> mapping = new List<KeyValuePair<string, HttpPostedFileBase>>();
+            string[] allKeys = files.AllKeys;
+            for (int i = 0; i < files.Count; i++) {
+                string key = allKeys[i];
+                if (key != null) {
+                    HttpPostedFileBase file = HttpPostedFileBaseModelBinder.ChooseFileOrNull(files[i]);
+                    mapping.Add(new KeyValuePair<string, HttpPostedFileBase>(key, file));
+                }
+            }
+
+            // turn the mapping into a 1:many dictionary
+            var grouped = mapping.GroupBy(el => el.Key, el => el.Value, StringComparer.OrdinalIgnoreCase);
+            return grouped.ToDictionary(g => g.Key, g => g.ToArray(), StringComparer.OrdinalIgnoreCase);
+        }
+
+    }
+}