Minecraft wiki entry for Development_versions, associated text: MC-116950 – Cannot place buttons, levers, torches... on barrier blocks
MC-116953 – A single horse is considered tamed multiple times in a row
MC-116974 – Can place block-dependent blocks on glassy blocks or leaves
MC-116976 – Shulker box duplication when placed below lever
MC-116985 – Buttons and levers can't be placed on the sides of corner stairs