NSNull vs. EONull
From EOFWiki
How MulleEOAccess deals with NSNull
MulleEOSQL can deal with values being NSNull but will always substitute them with EONull if encountered.
MulleEOAdaptor is supposed to be NSNull agnostic. Some adaptors may take NSNull as an EONull equivalent, but may never produce NSNull values on their own.
Problems in KVC
The original documentation of EOF for -[NSObject takeValuesFromDictionary:] specifies:
Sets properties of the receiver with values from aDictionary, using its keys to identify the properties. NSObject's implementation invokes takeValue:forKey: for each key-value pair, substituting nil for EONull values in aDictionary.
but this is now a method in Foundation, and therefore will actually use NSNull. (This is not a problem for MulleEOF itself)
Future
In a later version, EONull and NSNull will probably by unified at the expense of EONull.
