-Added ICloneable and DeepClone to JToken

-Changed DeepEquals to take into account possible floating point errors

Src/Newtonsoft.Json.Tests/Linq/JTokenTests.cs

@@ -646,5 +646,81 @@ namespace Newtonsoft.Json.Tests.Linq
       Assert.AreEqual("secondlastpie", (string)a[5]);
       Assert.AreEqual(7, a.Count());
     }
+
+    [Test]
+    public void DeepClone()
+    {
+      JArray a =
+        new JArray(
+          5,
+          new JArray(1),
+          new JArray(1, 2),
+          new JArray(1, 2, 3),
+          new JObject(
+            new JProperty("First", new JValue(Encoding.UTF8.GetBytes("Hi"))),
+            new JProperty("Second", 1),
+            new JProperty("Third", null),
+            new JProperty("Fourth", new JConstructor("Date", 12345)),
+            new JProperty("Fifth", double.PositiveInfinity),
+            new JProperty("Sixth", double.NaN)
+            )
+        );
+
+      JArray a2 = (JArray)a.DeepClone();
+
+      Console.WriteLine(a2.ToString(Formatting.Indented));
+
+      Assert.IsTrue(a.DeepEquals(a2));
+    }
+
+#if !SILVERLIGHT
+    [Test]
+    public void Clone()
+    {
+      JArray a =
+        new JArray(
+          5,
+          new JArray(1),
+          new JArray(1, 2),
+          new JArray(1, 2, 3),
+          new JObject(
+            new JProperty("First", new JValue(Encoding.UTF8.GetBytes("Hi"))),
+            new JProperty("Second", 1),
+            new JProperty("Third", null),
+            new JProperty("Fourth", new JConstructor("Date", 12345)),
+            new JProperty("Fifth", double.PositiveInfinity),
+            new JProperty("Sixth", double.NaN)
+            )
+        );
+
+      ICloneable c = a;
+
+      JArray a2 = (JArray) c.Clone();
+
+      Assert.IsTrue(a.DeepEquals(a2));
+    }
+#endif
+
+    [Test]
+    public void DoubleDeepEquals()
+    {
+      JArray a =
+        new JArray(
+          double.NaN,
+          double.PositiveInfinity,
+          double.NegativeInfinity
+        );
+
+      JArray a2 = (JArray)a.DeepClone();
+
+      Assert.IsTrue(a.DeepEquals(a2));
+
+      double d = 1 + 0.1 + 0.1 + 0.1;
+
+      JValue v1 = new JValue(d);
+      JValue v2 = new JValue(1.3);
+
+      Assert.IsTrue(v1.DeepEquals(v2));
+    }
   }
 }

Src/Newtonsoft.Json/Linq/JToken.cs

@@ -43,10 +43,13 @@ namespace Newtonsoft.Json.Linq
   /// Represents an abstract JSON token.
   /// </summary>
   public abstract class JToken : IJEnumerable<JToken>, IJsonLineInfo
-#if !(NET35 || NET20 || SILVERLIGHT)
-    , IDynamicMetaObjectProvider
+#if !SILVERLIGHT
+, ICloneable
 #endif
-    {
+#if !(NET35 || NET20 || SILVERLIGHT)
+, IDynamicMetaObjectProvider
+#endif
+  {
     private JContainer _parent;
     internal JToken _next;
     private static JTokenEqualityComparer _equalityComparer;
@@ -1298,5 +1301,21 @@ namespace Newtonsoft.Json.Linq
       return GetMetaObject(parameter);
     }
 #endif
+
+#if !SILVERLIGHT
+    object ICloneable.Clone()
+    {
+      return DeepClone();
+    }
+#endif
+
+    /// <summary>
+    /// Creates a new instance of the <see cref="JToken"/>. All child tokens are recursively cloned.
+    /// </summary>
+    /// <returns>A new instance of the <see cref="JToken"/>.</returns>
+    public JToken DeepClone()
+    {
+      return CloneToken();
+    }
   }
 }

Src/Newtonsoft.Json/Linq/JValue.cs

@@ -159,7 +159,13 @@ namespace Newtonsoft.Json.Linq
           else
             return Convert.ToInt64(objA, CultureInfo.InvariantCulture).Equals(Convert.ToInt64(objB, CultureInfo.InvariantCulture));
         case JTokenType.Float:
-          return Convert.ToDouble(objA, CultureInfo.InvariantCulture).Equals(Convert.ToDouble(objB, CultureInfo.InvariantCulture));
+          double d1 = Convert.ToDouble(objA, CultureInfo.InvariantCulture);
+          double d2 = Convert.ToDouble(objB, CultureInfo.InvariantCulture);
+          if (d1.Equals(d2))
+            return true;
+
+          // take into account possible floating point errors
+          return MathUtils.ApproxEquals(d1, d2);
         case JTokenType.Comment:
         case JTokenType.String:
         case JTokenType.Boolean:

Src/Newtonsoft.Json/Utilities/MathUtils.cs

@@ -124,5 +124,11 @@ namespace Newtonsoft.Json.Utilities
 
       return Math.Max(val1.Value, val2.Value);
     }
+
+    public static bool ApproxEquals(double d1, double d2)
+    {
+      // are values equal to within 12 (or so) digits of precision?
+      return Math.Abs(d1 - d2) < (Math.Abs(d1) * 1e-12);
+    }
   }
 }