[SQLObject] Comparison with None fails with DBMConnection

[Chris A. <ch...@at...>]

This code:
from SQLObject import *

conn = DBMConnection(".")

class TestMe(SQLObject):
    _connection = conn
    testCol = StringCol(default = None)

TestMe.dropTable(ifExists = True)
TestMe.createTable(ifNotExists = True)

t = TestMe.new()

print list(TestMe.select(TestMe.q.testCol == None))

fails with this error:
Traceback (most recent call last):
  File "test.py", line 14, in ?
    print list(TestMe.select(TestMe.q.testCol == None))
  File "/usr/lib/python2.3/site-packages/SQLObject/DBConnection.py",
line 1216, in next
    if SQLBuilder.execute(self.select.clause, self):
  File "/usr/lib/python2.3/site-packages/SQLObject/SQLBuilder.py", line
81, in execute
    return expr.execute(executor)
  File "/usr/lib/python2.3/site-packages/SQLObject/SQLBuilder.py", line
243, in execute
    return operatorMap[self.op.upper()](execute(self.expr1, executor),
KeyError: 'IS'

I found that by adding '"IS": operator.eq' to operatorMap in
SQLBuilder.py fixed this error, but I don't know if this will impact
other DB connection types.

Cheers,
Chris
-- 
Chris AtLee <ch...@at...>