Connection: add guard when updating name of currently open box during rename

lib/Connection.js

@@ -410,12 +410,6 @@ Connection.prototype.delBox = function(name, cb) {
 };
 
 Connection.prototype.renameBox = function(oldname, newname, cb) {
-  var destname = newname;
-  if (this._box
-      && oldname === this._box.name
-      && oldname.toUpperCase() !== 'INBOX')
-    destname = ''+oldname;
-
   var encoldname = escape(utf7.encode(''+oldname)),
       encnewname = escape(utf7.encode(''+newname)),
       self = this;
@@ -424,8 +418,14 @@ Connection.prototype.renameBox = function(oldname, newname, cb) {
     function(err) {
       if (err)
         return cb(err);
-      self._box.name = destname;
-      cb(err, self._box);
+
+      if (self._box
+          && self._box.name === oldname
+          && oldname.toUpperCase() !== 'INBOX') {
+        self._box.name = newname;
+        cb(err, self._box);
+      } else
+        cb();
     }
   );
 };