Fix to the JsonStringifier in dart_json.dart to escape eols. The error messages that frog sends t...

frog/server/dart_json.dart

Index: frog/server/dart_json.dart
===================================================================
--- frog/server/dart_json.dart	(revision 3201)
+++ frog/server/dart_json.dart	(working copy)
@@ -496,7 +496,8 @@
 
   // TODO: add others.
   static bool _needsEscape(int charCode) {
-    return JsonTokenizer.QUOTE == charCode || JsonTokenizer.BACKSLASH == charCode;
+    return JsonTokenizer.QUOTE == charCode || JsonTokenizer.BACKSLASH == charCode
+      || JsonTokenizer.NEW_LINE == charCode || JsonTokenizer.LINE_FEED == charCode;
   }
 
   static void _escape(StringBuffer sb, String s) {
@@ -507,10 +508,16 @@
     bool needsEscape = false;
     final charCodes = new List<int>();
     for (int i = 0; i < length; i++) {
-      final int charCode = s.charCodeAt(i);
+      int charCode = s.charCodeAt(i);
       if (_needsEscape(charCode)) {
         charCodes.add(JsonTokenizer.BACKSLASH);
         needsEscape = true;
+
+        if (JsonTokenizer.NEW_LINE == charCode) {
+          charCode = 110; // 'n'
+        } else if (JsonTokenizer.LINE_FEED == charCode) {
+          charCode = 114; // 'r'
+        }
       }
       charCodes.add(charCode);
     }