[rdiff-backup-users] [bug] Excluding hidden files the wrong way doesn't result in an error

[Ilario]

Excluding a hidden file without full path doesn't rise an error (as
happens with non hidden files) and copies it anyway; e.g.

mkdir temp
cd temp
mkdir .one
mkdir .two
mkdir three
mkdir four
rdiff-backup --exclude .one --exclude ./.two --exclude ./three . ../backup
ls -a ../backup
.  ..  four  .one  rdiff-backup-data

copies also the .one file and gives no warning.
Does the dot have a special meaning there?
Thanks,
Ilario