Merge pull request #300 from pyhrus/fix_jsonp_newline_escape

JSONP transport fails when sending JSON stringified message

lib/transports/polling-jsonp.js

@@ -17,6 +17,7 @@ module.exports = JSONPPolling;
  */
 
 var rNewline = /\n/g;
+var rEscapedNewline = /\\n/g;
 
 /**
  * Global JSONP callbacks.
@@ -211,6 +212,8 @@ JSONPPolling.prototype.doWrite = function (data, fn) {
   initIframe();
 
   // escape \n to prevent it from being converted into \r\n by some UAs
+  // double escaping is required for escaped new lines because unescaping of new lines can be done safely on server-side
+  data = data.replace(rEscapedNewline, '\\\n');
   this.area.value = data.replace(rNewline, '\\n');
 
   try {