ecryptfs-recover-private mounts successfully in /tmp/ecryptfs.XXXXXX but does not decrypt

I am here reopening the bug report about ecryptfs-recover-private command(see bug 1028532).That patch written by Dustin has fixed the issue that if mount command fails, user should be prompted (see r823: http://bazaar.launchpad.net/~ecryptfs/ecryptfs/trunk/revision/823).

I think user should be prompted that the file may not be decrypted successfully though user can mount it to /tmp/ecryptfs.XXXXXX because the manner of recovery is like that of "sudo mount -t ecryptfs <secure> <raw>" command, that is to say, we can mount with different passphrases but only the right passphrase can decrypt files.