Add range check for inferring JavaScript number

Author: mythz

src/ServiceStack.Text/Json/JsonUtils.cs

@@ -8,6 +8,9 @@ namespace ServiceStack.Text.Json
 {
 	public static class JsonUtils
 	{
+        public static long MaxInteger = 9007199254740992;
+        public static long MinInteger = -9007199254740992;
+
 		public const char EscapeChar = '\\';
 		public const char QuoteChar = '"';
 		public const string Null = "null";

src/ServiceStack.Text/JsonObject.cs

@@ -133,15 +133,35 @@ public static void WriteValue(TextWriter writer, object value)
                     || (firstChar == JsWriter.ListStartChar && lastChar == JsWriter.ListEndChar) 
                     || JsonUtils.True == strValue
                     || JsonUtils.False == strValue
-                    || NumberRegEx.IsMatch(strValue))
+                    || (NumberRegEx.IsMatch(strValue) && IsJavaScriptNumber(strValue)))
                 {
                     writer.Write(strValue);
                     return;
                 }
             }
             JsonUtils.WriteString(writer, strValue);
         }
-    }
+
+	    private static bool IsJavaScriptNumber(string strValue)
+	    {
+	        if (!strValue.Contains("."))
+	        {
+	            long longValue; 
+	            if (long.TryParse(strValue, out longValue))
+	            {
+	                return longValue < JsonUtils.MaxInteger && longValue > JsonUtils.MinInteger;
+	            }
+	            return false;
+	        }
+	        
+            double doubleValue;
+	        if (double.TryParse(strValue, out doubleValue))
+	        {
+	            return doubleValue < JsonUtils.MaxInteger && doubleValue > JsonUtils.MinInteger;
+	        }
+	        return false;
+	    }
+	}
 
 	public class JsonArrayObjects : List<JsonObject>
 	{