Hadd merge of files with different structures

Is it possible to merge several root files that have slightly different structures. That is, each is missing maybe 10% of the branches as compared to the other files.

I’d like to
-merge branches between import and export files
-create branches that do not yet exist in the export file so that it may be merged with other files that might contain this branch. Hadd doesn’t seem to have this functionality as I get:

[quote]Error in : The export branch and the import branch do not have the same number of branches (1168 vs 1230)

Is there any other way to accomplish this besides recreating the root files with empty branches?


By default hadd use a faster technique that require an exact match in structure. However you can change the default to the regular technique (read, unzip and unstream all the data and then stream it back, zip it and write) that can handle more cases by selecting a different compression level: