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+emptyds Overlay README
+
+DESCRIPTION
+    This package contains an OpenLDAP overlay called "emptyds" (empty
+    directory string) that eliminates empty values of type directory string
+    (OID 1.3.6.1.4.1.1466.115.121.1.15) from the list of the values in the
+    following manner:
+    
+    - add: All empty attribute values will be removed before the add request
+      is executed
+    - mod-replace: A replace with empty values will be modified to a replace
+      without values. As result the attribute will be deleted
+    - mod-add: All empty attribute values will be removed before the mod-add
+      request is executed
+    - mod-delete: All empty attribute values will be removed before the
+      mod-delete request is executed
+    
+    If removing all empty values from a modification makes it a no-op, that
+    modification is removed from the list.
+    
+    At module load time the emptyds overlay manipulates the syntax checking
+    so that it intercepts the syntax check and allows empty values for
+    attributes of type directory string only. Non-empty values continue to
+    go through the normal check routines. It is therefore very important to
+    configure the overlays in a way that ensures that the emptyds overlay gets
+    the control over the operation before any other overlay. Otherwise it
+    could come to the situation with empty attribute values in the data base.
+    
+    David Hawes' addpartial overlay has been used as starting point for this
+    overlay.
+     
+BUILDING
+    A Makefile is included, please set your LDAP_SRC directory properly.
+
+INSTALLATION
+    After compiling the emptyds overlay, add the following to your
+    slapd.conf:
+
+    ### slapd.conf
+    ...
+    moduleload emptyds.la
+    ...
+    overlay emptyds
+    ...
+    # before database directive...
+    # this overlay must be the last overlay in the config file to ensure that
+    # requests are modified before other overlays get them.
+    ...
+    ### end slapd.conf
+
+CAVEATS
+    - In order to ensure that emptyds does what it needs to do, it must be
+      the last overlay configured so it will run before the other overlays.
+
+---
+Copyright 2014-2022 The OpenLDAP Foundation.
+Portions Copyright (C) DAASI International GmbH, Tamim Ziai.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted only as authorized by the OpenLDAP
+Public License.
+
+A copy of this license is available in file LICENSE in the
+top-level directory of the distribution or, alternatively, at
+http://www.OpenLDAP.org/license.html.