Water source block gets destroyed when water flows on top of it

Still happening in 18w20a.

Also, a water source block is only destroyed if it wouldn't be replaced by standard infinite conditions. Oceans still count as an infinite source here, despite the current bug of making holes in oceans with buckets and whatnot, so you're not gonna drill a hole in the ocean with a waterfall or anything. Of course, it could just be that the water source is still actually being destroyed but then instantly getting replaced by a new water source. Either way, water sources shouldn't be getting destroyed when water flows into it from above. Key word is "into" - a water source won't be destroyed by water directly on top of it until that water actually flows down into the source, so waterfalls are literally destroying water source blocks.

Confirmed in 18w20c

Confirmed in 18w21a

Confirmed in 18w22c

 * Dig a 2 block hole.

 * Put water with a bukket in bottom

 * Put water with a bukket in top

 * Remove top water with a bukket

 * Bottom water has disappeared

Still happening in 1.13-pre1, which mostly follows the same conditions I wrote about in my previous comment here.

Basically, if a water source is directly above another water source (one that isn't infinite), the below source gets destroyed by the top one due to directly flowing into it. The only difference between the way the bug worked previously is that two water sources have to be directly on top of each other now instead of just having any ol' waterfall pour down into one.

Confirmed to still happen as above in 1.13-pre2.