simplify encodeURI using HttpUtility

Author: Jeroen Haegebaert

csharp/DiffMatchPatch.cs

@@ -21,6 +21,7 @@
 using System.Linq;
 using System.Text;
 using System.Text.RegularExpressions;
+using System.Web;
 
 namespace DiffMatchPatch {
  internal static class CompatibilityExtensions {
@@ -1473,7 +1474,7 @@ public List<Diff> diff_fromDelta(string text1, string delta) {
  // decode would change all "+" to " "
  param = param.Replace("+", "%2b");
 
- param = Uri.UnescapeDataString(param);
+ param = HttpUtility.UrlDecode(param);
  //} catch (UnsupportedEncodingException e) {
  // // Not likely on modern system.
  // throw new Error("This system does not support UTF-8.", e);
@@ -2248,7 +2249,7 @@ Regex patchHeader
  }
  line = text[textPointer].Substring(1);
  line = line.Replace("+", "%2b");
- line = Uri.UnescapeDataString(line);
+ line = HttpUtility.UrlDecode(line);
  if (sign == '-') {
  // Deletion.
  patch.diffs.Add(new Diff(Operation.DELETE, line));
@@ -2272,8 +2273,6 @@ Regex patchHeader
  return patches;
  }
 
- private static Regex HEXCODE = new Regex("%[0-9A-F][0-9A-F]");
-
  /**
  * Encodes a string with URI-style % escaping.
  * Compatible with JavaScript's encodeURI function.
@@ -2282,29 +2281,16 @@ Regex patchHeader
  * @return The encoded string.
  */
  public static string encodeURI(string str) {
- int MAX_LENGTH = 65520 - 1;
- // C# throws a System.UriFormatException if string is too long.
- // Split the string into 64kb chunks.
- StringBuilder sb = new StringBuilder();
- while (str.Length > MAX_LENGTH) {
- sb.Append(Uri.EscapeDataString(str.Substring(0, MAX_LENGTH)));
- str = str.Substring(MAX_LENGTH);
- }
- sb.Append(Uri.EscapeDataString(str));
- str = sb.ToString();
- // C# is overzealous in the replacements. Walk back on a few.
- str = str.Replace("+", " ").Replace("%20", " ").Replace("%21", "!")
- .Replace("%2A", "*").Replace("%27", "'").Replace("%28", "(")
- .Replace("%29", ")").Replace("%3B", ";").Replace("%2F", "/")
- .Replace("%3F", "?").Replace("%3A", ":").Replace("%40", "@")
- .Replace("%26", "&").Replace("%3D", "=").Replace("%2B", "+")
- .Replace("%24", "$").Replace("%2C", ",").Replace("%23", "#");
- // C# uses uppercase hex codes, JavaScript uses lowercase.
- return HEXCODE.Replace(str, new MatchEvaluator(lowerHex));
- }
-
- private static string lowerHex(Match m) {
- return m.ToString().ToLower();
+ // C# is overzealous in the replacements. Walk back on a few.
+ return new StringBuilder(HttpUtility.UrlEncode(str))
+ .Replace('+', ' ').Replace("%20", " ").Replace("%21", "!")
+ .Replace("%2a", "*").Replace("%27", "'").Replace("%28", "(")
+ .Replace("%29", ")").Replace("%3b", ";").Replace("%2f", "/")
+ .Replace("%3f", "?").Replace("%3a", ":").Replace("%40", "@")
+ .Replace("%26", "&").Replace("%3d", "=").Replace("%2b", "+")
+ .Replace("%24", "$").Replace("%2c", ",").Replace("%23", "#")
+ .Replace("%7e", "~")
+ .ToString();
  }
  }
 }