Minecraft wiki entry for Development_versions, associated text: MC-10946 – 2 hoppers funneling unstackable items into a 3rd hopper at the same time cause the 3rd hopper to not funnel items into a container.
MC-10948 – Dispensers continually shoot/use certain items like water buckets and flint&steel.
MC-10950 – Comparators still giving off power when hopper inventory is empty.
MC-10995 – Message "THIS TOO" in console.
MC-10997 – Powered dispensers and droppers update when a normal chest is opened or closed within 2 blocks.
MC-11019 – Full hoppers feeding into full hoppers causes the forward hopper to stall.