I was testing offline updates today with the new libhif-based PackageKit 0.9.3, and ended up with an empty Packages= line again.
After a debugging session, it turned out that this time too (similar to https://bugs.freedesktop.org/show_bug.cgi?id=79791) PK thought all those packages were in the CLEANUP state, and because of that didn't write them out to the offline-update-competed file.
The root cause turned out to be an enum mixup in libhif. I've got 2 libhif patches and a PK patch; I'm attaching them all here to make it easier to review them at one place.
Created attachment 101983 [details] [review]
Fix a mixup of HifStateAction and HifPackageInfo
Created attachment 101984 [details] [review]
Improve rpm callback handling for packages in the cleanup state
Created attachment 101985 [details] [review]
hif: Fix up a signature mismatch with a libhif signal handler
Pushed after IRC review.