Merge branch 'main-maszyman-metdata-roottree-dev2' into 'main'

make ROOTTREE default storage for metadata instead of ROOTTREEINDEX

See merge request atlas/athena!67972

Control/AthenaConfiguration/python/AllConfigFlags.py

@@ -258,7 +258,7 @@ def initConfigFlags():
 
     acf.addFlag('Output.TreeAutoFlush', {})  # {} = automatic for all streams, otherwise {'STREAM': 123}
     acf.addFlag('Output.StorageTechnology.EventData', 'ROOTTREEINDEX')  # Set the underlying POOL storage technology for event data
-    acf.addFlag('Output.StorageTechnology.MetaData', 'ROOTTREEINDEX')  # Set the underlying POOL storage technology for metadata
+    acf.addFlag('Output.StorageTechnology.MetaData', 'ROOTTREE')  # Set the underlying POOL storage technology for metadata
 
     # Might move this elsewhere in the future.
     # Some flags from https://gitlab.cern.ch/atlas/athena/blob/master/Tracking/TrkDetDescr/TrkDetDescrSvc/python/TrkDetDescrJobProperties.py

Control/xAODRootAccess/Root/Utils.cxx

@@ -320,7 +320,7 @@ namespace xAOD {
          const TObjArray * pBranches = tree->GetListOfBranches();
          const std::regex pattern( ".*" + pre + ".*" );
 
-         for( int i = 0; i < pBranches->GetLast() ; ++i ) {
+         for( int i = 0, nLast = pBranches->GetLast(); i <= nLast; ++i ) {
             const std::string name = pBranches->At(i)->GetName();
 
             if( std::regex_match( name, pattern ) )