Import LDIF by pasting into textfield

I was looking for a replacement of the phpldapadmin Import tool, where you can paste LDIF formatted text into a text field and import it.

@MCMic on IRC suggested to try to change line 113 in addons/ldapmanager/class_ldapmanager.inc by replacing FileAttribute into FileTextAreaAttribute. After doing that, I did get a text field, but whatever I wrote in there was not imported at all...