Player can climb powder snow without leather boots

Bug Description

 The player can climb out of Powder Snow by holding the jump button, where as in Java the top of the block acts as a solid (unless the player is wearing leather boots)

Steps to reproduce

 - Place a tower of Powder Snow

 - Enter it and hold jump

What was expected

 The player would hit their head on the top of the block and be trapped inside the tower

What was observed

 The player climbs out of the tower