Ticket #47367 - (phase 1) ldapdelete returns non-leaf entry error while trying to remove a leaf entry
    
    Bug description: Replication conflict confuses the numsubordinate
    count, which leaves an entry that cannot be deleted even its
    subordinate entries are all removed.
    
    Fix description:
    [urp.c] get_dn_plus_uniqueid: a logic to create a conflict DN
      had a bug.  It used to call slapi_sdn_get_rdn to get the rdn.
      The function slapi_sdn_get_rdn blindly returned the "dn" field
      without checking whether the field is NULL or not.  Instead,
      this patch changes the interface of the helper function get_
      dn_plus_uniqueid and use the original Slapi_DN with slapi_
      sdn_get_dn, then generates the conflict DN "nsuniqueid=...+
      <RDN>,<PARENT>".
    [ldbm_delete.c] There is a case a parent of a delete-candidate
      entry runs into a conflict and multiple parent entries exist.
      Once it occurs, a parent entry found by the parent dn string
      may not be the entry which manages the numsubordinate count
      the delete-candidate entry belonging to.  It confuses the
      numsubordinate counts and leaves an entry which cannot be
      deleted due to the numsubordinate count mismatch. This patch
      retrieves parent entry by parent id if it is available.
    [ldbm_entryrdn.c] When traversing the DIT, a special treatment
      is needed for a tombstone entry. I.e, 2 RDNs (nsuniqueid=...,
      <RDN>) is treated as one RDN.  It should decrement the index
      (rdnidx) one more to point to the right position of the RDN
      array in Slapi_RDN.
    [ldbm_search.c] When checking the scope of an entry in ldbm_
      back_next_search_entry_ext, a tombstone entry was not properly
      examined.  This patch introduces a new slapi api slapi_sdn_
      scope_test_ext.
    [dn.c] In slapi_sdn_get_rdn, use slapi_sdn_get_dn to get the
      dn value of Slapi_DN.  It was one cause of the problem in
      get_dn_plus_uniqueid (urp.c).
      This patch adds slapi_sdn_scope_test_ext, which takes flags
      to indicates the first argument dn is a tombstone sdn.
      Also, this patch replaces "malloc + strcpy + strcat" with
      slapi_ch_smprintf to improve the readability of the code.
    [rdn.c] This patch replaces "malloc + strcpy + strcat" with
      slapi_create_dn_string to normalize the newly added rdn and
      improve the readability of the code.
    
    Reviewed by Rich (Thank you!!)
    
    https://fedorahosted.org/389/ticket/47367