Here's an easy bug to fix!

When I use 'pick block' on a Command Block, it doesn't save the 'conditional/unconditional' state of the block being copied.

How to duplicate:

1) Put a Command Block in the game world.

2) Right-click the Command Block and make it 'conditional' (arrow texture on trailing edge has a divot in it). Put some code into the Command Block.

3) Hold 'ctrl' and middle-click the block to 'pick block' it.

4) Put the 'pick block' copy of the Command Block into your world.

5) The 'pick block' copy has all the code in it, but its state has been reverted to the default 'unconditional' state (arrow texture on trailing edge is flat).

That's about it... Pick Block a 'conditional' Command Block, and it isn't a 'conditional' Command Block anymore when you place it. Hope you can get this fixed quick, because it's a pain to have to reset the conditional state of a lot of copied Command Blocks after they're placed.