Minecraft wiki entry for Development_versions, associated text: MC-138530 – Crash when clicking on 'Minecraft Realms' button.
MC-138547 – Opening a 1.12.2 world in 18w44a or newer causes terrain to regenerate.
MC-139018 – Scaffolding doesn't stack from the bottom under water.
MC-139975 – Hover/click events in books are vertically misaligned by about a third of a row of text.
MC-140591 – Placing sweet berry bushes doesn't play sound/destroying sweet berry bushes plays stone break sound.
MC-141036 – Game crashes when shift-clicking a newly named item out of an anvil.
MC-141080 – Scaffolding does not replace vines when attempting to stack from the bottom.
MC-141730 – /data remove-ing multiple elements from a list skips every other match in sub-sequence.
MC-141814 – /data modify can create corrupt NBT lists (crashes).
MC-141815 – Using /data modify to replace all list values with a different type wipes the list.