Using python to read a dumbdbm db created with jython
on Windows, the index got erased.  The load failed with
an exception due to the python os.linesep being "\n",
while the jython version created the db with "\r\n".  

On exit, the python dumbdbm module committed the empty
index it had read, destroying the db.  commit (or sync)
is implicitly being called on exit from python.

dumbdbm ignores the flag it was opened with and commits
even if it was opened with 'r'.  jython doesn't seem to
support any other standard dbm implementation, so I'm
stuck with dumbdbm.

The problem can be worked around by setting os.linesep
manually to enforce consistency.