Comment 18 for bug 1078697

This commit should prevent apt-ftparchive to generate Checksum-listings which just includes the dsc file and nothing else (General mode of operation: It copies the Checksum-listings from the dsc file and adds the dsc file to it). So that would explain the diveintopython example (if diveintopython.dsc really has no SHA1/SHA256 checksums included), but not cvstrac as cvstrac.dsc seems to include checksums apt-ftparchive copied but "forgot" to add checksums for the dsc file.