Fix a potential null dereference.
Fix a potential null dereference.

The bug was discovered by running runarray1 test in runtime_cxxmodules mode.

root-mirror/cling,root-mirror/cling,karies/cling,root-mirror/cling,karies/cling,karies/cling,karies/cling,root-mirror/cling,root-mirror/cling,root-mirror/cling,karies/cling,karies/cling