Import Contribution - Match on Contact ID Fails

For Contribution Import (as well as Membership, Activity and Event) - users should be able to map a "Contact ID (Match to Contact)" column - and if so, Name/Email is not required for matching imports. This is now broken on trunk (works in 1.6). With the attached file, you get the following error:

"Missing required contact matching fields. (Should be First AND Last Name or Primary Email or First Name, Last Name AND Primary Email.)"