-Bug fix

Src/Newtonsoft.Json.Tests/JsonConvertTest.cs

@@ -580,6 +580,21 @@ namespace Newtonsoft.Json.Tests
             Assert.AreEqual(@"""It's a good day\r\n\""sunshine\""""", json);
         }
 
+        [Test]
+        public void ToStringStringEscapeHandling()
+        {
+            string v = "<b>hi " + '\u20AC' + "</b>";
+
+            string json = JsonConvert.ToString(v, '"');
+            Assert.AreEqual(@"""<b>hi " + '\u20AC' + @"</b>""", json);
+
+            json = JsonConvert.ToString(v, '"', StringEscapeHandling.EscapeHtml);
+            Assert.AreEqual(@"""\u003cb\u003ehi " + '\u20AC' + @"\u003c/b\u003e""", json);
+
+            json = JsonConvert.ToString(v, '"', StringEscapeHandling.EscapeNonAscii);
+            Assert.AreEqual(@"""<b>hi \u20ac</b>""", json);
+        }
+
         [Test]
         public void WriteDateTime()
         {

Src/Newtonsoft.Json.Tests/PerformanceTests.cs

@@ -182,7 +182,7 @@ namespace Newtonsoft.Json.Tests
         [Test]
         public void DeserializeLargeJson()
         {
-            for (int i = 0; i < 100; i++)
+            for (int i = 0; i < 5; i++)
             {
                 using (var fs = System.IO.File.OpenText("large.json"))
                 using (JsonTextReader jsonTextReader = new JsonTextReader(fs))

Src/Newtonsoft.Json/JsonConvert.cs

@@ -409,11 +409,6 @@ namespace Newtonsoft.Json
             return ToString(value, '"');
         }
 
-        public static string ToString(string value, StringEscapeHandling stringEscapeHandling)
-        {
-            return ToString(value, '"', stringEscapeHandling);
-        }
-
         /// <summary>
         /// Converts the <see cref="String"/> to its JSON string representation.
         /// </summary>
@@ -425,6 +420,13 @@ namespace Newtonsoft.Json
             return ToString(value, delimiter, StringEscapeHandling.Default);
         }
 
+        /// <summary>
+        /// Converts the <see cref="String"/> to its JSON string representation.
+        /// </summary>
+        /// <param name="value">The value to convert.</param>
+        /// <param name="delimiter">The string delimiter character.</param>
+        /// <param name="stringEscapeHandling">The string escape handling.</param>
+        /// <returns>A JSON string representation of the <see cref="String"/>.</returns>
         public static string ToString(string value, char delimiter, StringEscapeHandling stringEscapeHandling)
         {
             if (delimiter != '"' && delimiter != '\'')

Src/Newtonsoft.Json/JsonTextWriter.cs

@@ -253,12 +253,7 @@ namespace Newtonsoft.Json
 
         private void UpdateCharEscapeFlags()
         {
-            if (StringEscapeHandling == StringEscapeHandling.EscapeHtml)
-                _charEscapeFlags = JavaScriptUtils.HtmlCharEscapeFlags;
-            else if (_quoteChar == '"')
-                _charEscapeFlags = JavaScriptUtils.DoubleQuoteCharEscapeFlags;
-            else
-                _charEscapeFlags = JavaScriptUtils.SingleQuoteCharEscapeFlags;
+            _charEscapeFlags = JavaScriptUtils.GetCharEscapeFlags(StringEscapeHandling, _quoteChar);
         }
 
         /// <summary>

Src/Newtonsoft.Json/Utilities/JavaScriptUtils.cs

@@ -72,6 +72,17 @@ namespace Newtonsoft.Json.Utilities
 
         private const string EscapedUnicodeText = "!";
 
+        public static bool[] GetCharEscapeFlags(StringEscapeHandling stringEscapeHandling, char quoteChar)
+        {
+            if (stringEscapeHandling == StringEscapeHandling.EscapeHtml)
+                return HtmlCharEscapeFlags;
+
+            if (quoteChar == '"')
+                return DoubleQuoteCharEscapeFlags;
+
+            return SingleQuoteCharEscapeFlags;
+        }
+
         public static bool ShouldEscapeJavaScriptString(string s, bool[] charEscapeFlags)
         {
             if (s == null)
@@ -230,10 +241,12 @@ namespace Newtonsoft.Json.Utilities
 
         public static string ToEscapedJavaScriptString(string value, char delimiter, bool appendDelimiters, StringEscapeHandling stringEscapeHandling)
         {
+            bool[] charEscapeFlags = GetCharEscapeFlags(stringEscapeHandling, delimiter);
+
             using (StringWriter w = StringUtils.CreateStringWriter(StringUtils.GetLength(value) ?? 16))
             {
                 char[] buffer = null;
-                WriteEscapedJavaScriptString(w, value, delimiter, appendDelimiters, (delimiter == '"') ? DoubleQuoteCharEscapeFlags : SingleQuoteCharEscapeFlags, stringEscapeHandling, ref buffer);
+                WriteEscapedJavaScriptString(w, value, delimiter, appendDelimiters, charEscapeFlags, stringEscapeHandling, ref buffer);
                 return w.ToString();
             }
         }