From Bertrand and Philippe: Avoid segmentation fault (and other potential problems) when attaching a non ROOT file to a TFile (for example by doing a file open) by marking the file as non-writable.
From Bertrand and Philippe:
Avoid segmentation fault (and other potential problems) when attaching a non ROOT file
to a TFile (for example by doing a file open) by marking the file as non-writable.


git-svn-id: ecbadac9c76e8cf640a0bca86f6bd796c98521e3@39048 27541ba8-7e3a-0410-8455-c3a389f83636

dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root,dawehner/root