Again "Failed to remove backlin of memberOf when deleting" with debug info

[Andrej Gessel]

Hello list,

I'm testing new Samba version 4.8.0rc4 as an RODC with Windows server 
2008R2 as RWDC.

1) join is done with following command:

samba-tool domain join SAMDOM.LOCAL RODC --domain-critical-only 
--configfile /path/smb.conf --username admin --dns-backend 
SAMBA_INTERNAL --server RWDC --site NewSite

2) After RODC was joined and samba was started i saw following error in log:

Failed to apply records: 
../source4/dsdb/samdb/ldb_modules/repl_meta_data.c:4373: Failed to 
remove backlink of memberOf when deleting 
CN=_User.Name\0ADEL:4cab6805-fd33-4edb-9bb2-702f7dce1210,CN=Deleted 
Objects,DC=samdom,DC=local: Attribute member doesn't exist for target 
GUID 4cab6805-fd33-4edb-9bb2-702f7dce1210: Operations error
Failed to commit objects: 
WERR_GEN_FAILURE/NT_STATUS_INVALID_NETWORK_RESPONSE
dreplsrv_op_pull_source(WERR_BAD_NET_RESP) for DC=samdom,DC=local

3) ldbsearch -H /path/DC=SAMDOM,DC=LOCAL.ldb 
'(distinguishedname=CN=_User.Name\0ADEL:4cab6805-fd33-4edb-9bb2-702f7dce1210,CN=Deleted 
Objects,DC=samdom,DC=local)' memberof
# record 1
dn: ...
memberof: <GUID=...>;<SID=...>;CN=GROUP,OU=GROUPSX,DC=SAMDOM,DC=LOCAL

4) ldbsearch -H /path/DC=SAMDOM,DC=LOCAL.ldb 
'(distinguishedname=CN=GROUP,OU=GROUPSX,DC=SAMDOM,DC=LOCAL)' member
# record 1
dn: ...
member: ...
member: 
<GUID=4cab6805-fd33-4edb-9bb2-702f7dce1210>;<RMD_ADDTIME=0>;<RMD_CHANG
  ETIME=0>;<RMD_FLAGS=0>;<RMD_INVOCID=...>;<RMD_LOCAL_USN=1>;<RMD_ORIGINATING_
USN=1>;<RMD_VERSION=1>;<SID=...>;CN=_User.Name\0ADEL:4cab6805-fd33-4edb-9bb
  2-702f7dce1210,CN=Deleted Objects,DC=samdom,DC=local

5) I think that the problem is in the 
"comparison_fn"(la_guid_compare_with_trusted_dn) that is ONLY used in 
BINARY_ARRAY_SEARCH_GTE 
(https://github.com/samba-team/samba/blob/60c7969e20ddc72d1d2a9dd1bd116d47df07ab02/source4/dsdb/common/util_links.c#L203) 
. I replaced this macro with simple for-loop and it works again.

ldb_index.c:

The array is assumed to be sorted by the same comparison_fn as the
search (with, for example, qsort)

I do not have fix for it now, so i hope, that you can help me to find 
the best solution.


Andrej