Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.Web/ModelBinding/ValueProviderUtil.cs

@@ -0,0 +1,19 @@
+namespace System.Web.ModelBinding {
+    using System;
+
+    internal static class ValueProviderUtil {
+
+        public static string CreateSubPropertyName(string prefix, string propertyName) {
+            if (String.IsNullOrEmpty(prefix)) {
+                return propertyName;
+            }
+            else if (String.IsNullOrEmpty(propertyName)) {
+                return prefix;
+            }
+            else {
+                return prefix + "." + propertyName;
+            }
+        }
+
+    }
+}