1.2.4 breaks queryset.extra(select={'__double_underscore_field': ...})

[Craig de Stigter]

In 1.2.3 this worked fine:

qs = qs.extra(select={'__foo': "1"}).order_by('__foo')

Now in 1.2.4 I get:

FieldError at /test/
Cannot resolve keyword '' into field. Choices are [...]

I believe the solution is to change ​django/db/models/sql/compiler.py#L371

pieces = name.split(LOOKUP_SEP)

to

pieces = filter(None, name.split(LOOKUP_SEP))

[Craig de Stigter]

Actually.. that solution is munted since it strips off the underscores :(

Perhaps a regex fix?

We've already worked around this with s/foo/_foo/ ...

[Russell Keith-Magee]

I can't reproduce this problem on 1.2.3, 1.2.4 or trunk. If you can provide a more complete example that fails, feel free to reopen.