Silence a warning.


git-svn-id: https://root.cern.ch/svn/root/trunk@49312 27541ba8-7e3a-0410-8455-c3a389f83636
Imporve the printout of Transactions.


git-svn-id: https://root.cern.ch/svn/root/trunk@49313 27541ba8-7e3a-0410-8455-c3a389f83636
Don't be too harsh if somebody asks for the last nested transaction.


git-svn-id: https://root.cern.ch/svn/root/trunk@49314 27541ba8-7e3a-0410-8455-c3a389f83636
Check whether the begun transaction is the one being committed.


git-svn-id: https://root.cern.ch/svn/root/trunk@49315 27541ba8-7e3a-0410-8455-c3a389f83636
Add test.


git-svn-id: https://root.cern.ch/svn/root/trunk@49316 27541ba8-7e3a-0410-8455-c3a389f83636