On the 'move-tracking-2' branch: Refactoring of branch state and branch transaction objects to allow implementing different subclasses with different private data.
Make generic class constructors that subclasses can re-use.
* subversion/include/private/svn_branch.h, subversion/libsvn_delta/branch.c (svn_branch_txn_create, svn_branch_state_create): Turn this into a 'base class' contructor. (branch_txn_create, branch_state_create): Let this be the constructor for the specific implementation. Adjust all callers.