Follow-up to r26499.
Follow-up to r26499.

* subversion/tests/cmdline/merge_tests.py
  (merge_to_sparse_directories): Make merges to test '--dry-run' too.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion