Blocky and fully bright areas appearing underwater

Looking at this, I think the bug I found is a reproduction of this, though as I said, it's not exactly consistent.

Can confirm in 18w16a. (see pic)

Confirmed in 18w19b. 

seed: -8300275442758179407

xyz: 276 69 -289

So the weird light areas disappear if you do the following:

1. find the edge and place a block on the dark side

2. break the block

3. the light will now return to it's proper faded gradient

   [media]

Confirmed for 18w20a.

Also occuring in 18w20c, and only in old chunks (see attached screenshots of old and new chunks). I am convinced that this issue is somehow related to MC-129725, because there the lighting issue seems to occur in exactly the same way except with caves (and you know, the fact that light is going through solid blocks). I even re-did the pumpkin thing above with a weirdly-lit mineshaft and the same thing happened- although it should be noted that after the pumpkin is removed, either in the ocean or in a cave, it is still an issue because the light area stays "lit" without a light source present, only the edges smooth to blend with the dark area. 

Old chunks (Ignore air pockets, that's unrelated issue MC-129625): 

New Ocean:

Pumpkin Test in mineshaft: 

Confirmed for 18w22b.

This bug occurs whenever blocks, other than the default generation of the world, are present above water. I made a world in the current snapshot, 18w22b, and placing blocks manually, using /setblock, or using /fill maxes out the light level in the chunk tested in, but only in the water. If too big of an area is used with the /fill command, the light between the fill area and the water will remain at the following places: 

1. The corners of each chunk just under the fill area (basically at the corner of a chunk in the area the /fill command was used, the sky light level will always remain at 14. It's just easier to see the light under the fill area since there isn't light down there). Placing a block five blocks under the light will remove it.

2. At the water's surface and one block under it.

After the player leaves the area and comes back to it, the light at the surface of the water will be 13 and will increase to 15 two blocks down. The light level will remain at its maximum until one block below the ocean floor. I don't know if this should be classified as another bug, but it's very closely related if so.

Could someone please add the info in this comment by @unknown into the bugpost description?

It's easily reproducable by setblock'ing a block above water, see:

Confirmed for 1.13-pre1.

Confirmed for 1.13-pre2.

This issue relates to MC-129236 and MC-126138 because the water is acting like air. When air doesn't have any blocks above it, its sky light level is based purely on the day-night cycle and rain/storms. The same happens to water with this bug, but the water ignores blocks and rain/storms (is only affected by the day-night cycle). However when it is night, the sky light level of the whole body of water is at 4 instead of 0 further down.

Going back to the bug report, the game thinks the water is supposed to be at the same sky light level air is at based on the day-night cycle. So when the area above the water is updated by any means (except F3 + A), the light is "corrected".

Confirmed for 1.13 pre-3

Issue still persisting on my 1.13 Pre-4 World. The transparent block will go away when replaced, but will persist after restarting the world, possible fixes for this?

Yeah it is still broken for me too.