"Crawling" underneath glass/grass paths/other transparent blocks causes bugs

When exiting swimming mode in a one-block high dry space, the player will remain in a swimming/crawling state, a hopefully intentional feature. This continues fine provided the block above the player is a solid non-transparent cube. However, if this is not the case, some closely-linked glitchy effects can be noted:

• The player will appear to be standing up, instead of being in a crawling state. In third-person mode, the knees will be treated as the player's eyes.
• The player will no longer be able to walk underneath solid non-transparent blocks (they can still move between transparent cubes by walking). It is possible to sprint back into them, but the player will still appear standing.