Dear ROOT Experts,
I am converting column-wise-ntuples from HBOOK files to ROOT with h2root. If worked fine with older versions of ROOT, then with 5.34/25 h2root was crashing (on several Ubuntu/Debian machines) - probably due to this issue:
sft.its.cern.ch/jira/si/jira.is … -6937.html
Indeed, in ROOT version 5.34/26 h2root does not crash anymore. However, the produced root tree is not correct. All tree branches whose type after conversion is UChar_t contain only zeros. The original ntuples contain correct values and they were converted correctly with h2root from older ROOT versions (for instance, 5.32/04).
The original columns of the ntuples are all of INTEGER type, but after conversion with h2root some of them are made UChar_t and some Int_t. The problem seems to concern all columns which were converted to UChar_t, but also some of those which became Int_t.
I believe this problem must be related to the change to ‘exchange mode’ described in the above link. Do you know what may be the reason for this behavior? Also, for a possible workaround it would be useful to know what are the rules for converting an integer ntuple column to either UChar_t or Int_t type. Is this described somewhere?
Thank you in advance!