When rename of folder fails, original folder is no more working correctly

In case of failure during rename, the original folder behaves incorrectly.

In particular, renaming a folder to the same name may throw an error depending on the imap server, causing the same problem.
This may esily happen by double clicking on a folder: the folder name enters edit mode - if you click elsewere to cancel edit, rename with the same name will be fired, ending up with the error and then the problem.