3 bugs from latest snapshot

3 bugs

1. i somehow duplicated a diamond pickaxe by switching items with F and blocking with my sword , i couldnt redo it it just happend once

2. when you put a placeable block in your left hand and then place and break the block , the block will not be added back to the offhand stack but instead in the main item bar

3. when placing a block with your left hand the right hand is swinging