A bucket of water can be placed on top/beside of a waterloggable block, if said block is already waterlogged.
Replicate:
1) Place down any kind of waterloggable block; For example: any kind of slab (bug cannot be replicated with ladders/sign while standing, works only on sign when crouching)
2) Place water via bucket in the slab: slab will become waterlogged
3) Place water once again in the (now waterlogged) slab: water will be placed on to/beside of the waterlogged slab
Video: https://www.youtube.com/watch?v=VMt4vkNlrtE&feature=youtu.be
Comments 4
It's a possibility, however, buckets of water can be emptied in normal water sources / flowing water. Of course only when an adjacent block has a hitbox. If waterplacing in waterlogged blocks does follow this game mechanic, then indeed it is intended that the bucket would be poured out beside a waterlogged block.
Resolve as a duplicate of MC-127110.
I think this is intended behavior. Otherwise you would get that, what you see in MC-126906.