null hitResult when no entity or block is in focus while looking through blocks without the ray trace intersecting the blocks themselves

Game Output

[16:57:52] [Client thread/ERROR]: Null returned as 'hitResult', this shouldn't happen!
[16:57:52] [Client thread/WARN]: Null returned as 'hitResult', this shouldn't happen!

How to reproduce

• Go to a wall which has at least 6 (+1 where you should stand) ladders below or above you
• Click the mouse
• Observe that the item in your hand is not swung, and that a warning is printed in the log

Affects all blocks that allow you to stand in them and punch without hitting them, including:

• Ladders
• Vines
• Iron bars
• Glass panes
• Portal blocks
• ...

Not restricted to only the vertical axis - can also happen when looking sideways.

Code analysis

Code analysis by Marcono1234 can be found in this comment.