Walking towards a wall while in water half a block high causes you to jump

When you are standing on a slab submerged in water and walking towards a wall, the character starts jumping repeatedly on his own (automatic jump is disabled).

Steps to Reproduce:

• Put a slab.
• Put water on the slab.
• Build a wall next to the slab.
• Get on the submerged slab and walk to the wall. 

Observed Results:

Once the character hits the wall, he will start jumping repeatedly for no reason.

Expected Results:

The character should only run into the wall without jumping.