tree ea7ef25d5174cb14c495d555500fae8896ab599d
parent d4adce5cc5a2337beddc2b24cde6b27cd9c459e3
author Alexander Afanasyev <alexander.afanasyev@ucla.edu> 1331672444 -0700
committer Alexander Afanasyev <alexander.afanasyev@ucla.edu> 1331672444 -0700

Before add ing a new state to diff log, trying to remove one that has the same hash.

Note that all pointers to next diff state will be preserved as it is
(thanks to shared_ptr).

There is a need for next pointer optimizations, but we can postpone it
until we implement diff log flattening functionality.