I/O

Fix the order of creation of the TStreamerInfo during the opening of a ROOT file to insure that the CollectionProxy are properly setup.
Fix problem: "recover warning when opening an empty file created with TXNetFile" which was due to a bad check in TFile::Recover (line TFile.cxx:1561) where the inheritance from TFile should be checked instead of requiring the name to be TFile.
In TBranch::File, in the case of importing the data directly from an external TBuffer, remove 80 char limit on reading the class name
Re-enable support for the rootrc configuration Root.ZipMode.

Data Model Evolution

First step in the implemantation of the infrastructure for the new Data Model Evolution Scheme.
This Data Model Evolution is brought to your courtesy of BNL/STAR/ATLAS/Fermi/Cern

Current Capabilities

Assign values to transient data members
Rename classes
Rename data members
Change the shape of the data structures or convert one class
structure to another
Change the meaning of data members
Ability to access the TBuffer directly when needed
Ensure that the objects in collections are handled in the same way as the ones stored separately
Supported in object-wise, member-wise and split modes.

Coming soon

Make things operational also in bare ROOT mode
Ability to transform data before writing
Support for changing the class type of nested object in a split branch
Support for access to onfile version of nested objects from within the parent rule

LinkDef rule syntax

Setting a transient member:

  #pragma read sourceClass="ACache" targetClass="ACache" source=""
  version="[1-]" target="zcalc" \
  code="{ zcalc = false; }"

Setting a new member from 2 removed members:

  #pragma read sourceClass="ACache" targetClass="ACache"
  source="int x; int y; char c" version="[8]" target="z" \
  code="{ z = onfile.x*1000 + onfile.y*10; }"

Renaming a class:

   #pragma read sourceClass="ACache" version="[8]"
   targetClass="Axis" \
   source="int x; int y;" target="z" \
   code="{ z = onfile.x*1000 + onfile.y*
   #pragma read sourceClass="ACache" version="[9]"
   targetClass="Axis";

See the long form documentation

Selection XML syntax