In the previous snapshot, a trapped chest placed next to a normal chest would function perfectly fine and save space. After the update, all of the trapped chests I had placed were missing, along with the items inside. The item frames that were on them dropped as well.
Was this functionally removed?
Or is this a bug?
1.4.7 doesn't include stuff from 1.5 snapshots. It merely an bugfix release for those who uses stable versions only.