[389-devel] single valued attribute update resolution

[Ludwig Krispenz]

There are still scenarios where replication can lead to inconsistent 
states for single valued attributes, which I think has two reasons:
- for single valued attributes there are scenarios where modifications 
applied concurrently cannot be simply resolved without violating the schema
- the code to handle single valued attribute resolution is quite complex 
and has always been extended to resolve reported issues, not making it 
simpler

I tried to specify all potential scenarios which should be handled and 
what the expected consistent state should be. In parallel writing a test 
suite based on lib389 test framework to provide testcases for all 
scenarios and then test the current implementation. The doc and test 
suite can be used as a reference for a potential rework of the update 
resolution code.

Please have a look at: 
http://port389.org/wiki/Update_resolution_for_single_valued_attributes

comments, corrections, additonal requirements are welcome - the doc is 
not final :-)

Thanks,
Ludwig