Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/Util/HttpEncoderUtility.cs

@@ -0,0 +1,62 @@
+//------------------------------------------------------------------------------
+// <copyright file="HttpEncoderUtility.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+/*
+ * Helper class for common encoding routines
+ *
+ * Copyright (c) 2009 Microsoft Corporation
+ */
+
+namespace System.Web.Util {
+    using System;
+    using System.Web;
+
+    internal static class HttpEncoderUtility {
+
+        public static int HexToInt(char h) {
+            return (h >= '0' && h <= '9') ? h - '0' :
+            (h >= 'a' && h <= 'f') ? h - 'a' + 10 :
+            (h >= 'A' && h <= 'F') ? h - 'A' + 10 :
+            -1;
+        }
+
+        public static char IntToHex(int n) {
+            Debug.Assert(n < 0x10);
+
+            if (n <= 9)
+                return (char)(n + (int)'0');
+            else
+                return (char)(n - 10 + (int)'a');
+        }
+
+        // Set of safe chars, from RFC 1738.4 minus '+'
+        public static bool IsUrlSafeChar(char ch) {
+            if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || (ch >= '0' && ch <= '9'))
+                return true;
+
+            switch (ch) {
+                case '-':
+                case '_':
+                case '.':
+                case '!':
+                case '*':
+                case '(':
+                case ')':
+                    return true;
+            }
+
+            return false;
+        }
+
+        //  Helper to encode spaces only
+        internal static String UrlEncodeSpaces(string str) {
+            if (str != null && str.IndexOf(' ') >= 0)
+                str = str.Replace(" ", "%20");
+            return str;
+        }
+
+    }
+}