Aquatic mobs can pathfind through solid waterlogged blocks

*Partner Rank:*

4

*Partner Team Reporting:*

Everbloom Studios

*Verification builds:*

beta 1.11.0.10 (Release_2012206) and beta 1.12.0.5 (Release_2199655) on Windows 10

*Summary:*

Mobs with underwater pathfinding can create paths that go through solid waterlogged blocks, even when they can't go through them.

*Impact:*

Aquatic mobs, custom or not, may not appear to move in their available space since they stay so fixated on waters they cannot reach. This is more likely to be noticed in player-built environments.

*Repro Steps:*

1. Join a world, find an ocean, lake, river or make a large pool of water.
2. Pick a spot in the water pool and make a box around it, using solid waterloggable blocks such as stairs and/or barriers. These walls should extend all the way from the bottom of the pool to the surface, and shouldn't let fish exit the box.
3. Recommended but not necessary: Enable path drawing either via the Debug menu or the /paths command.
4. Spawn some fish inside the box

*Observed Results:*

The fish start making paths through the blocks and ultimately failing to get to their destination.

*Expected Results:*

The paths made by the fish should be contained entirely within the box they are trapped in.

*Screenshots/Videos attached: Yes/No*

Yes

*Regression Builds:*

Unknown