Sort sale line per parcel key fails
It fails with: TypeError: unorderable types: NoneType() < NoneType()
See: https://groups.google.com/d/msgid/tryton/4CD16F9A-49E1-4E41-9F0C-C1443E8B27B8%40symetrie.com
It fails with: TypeError: unorderable types: NoneType() < NoneType()
See: https://groups.google.com/d/msgid/tryton/4CD16F9A-49E1-4E41-9F0C-C1443E8B27B8%40symetrie.com