The Bug:

With block that can be destroyed instantly on hand,face to a top  of a block.Left click and right click at same time,keeping for seconds.When stop to obsever,you can see the crack on block don't disappear instantly but exist several seconds.If you Left click and right click too long,long enough to destory the block ,the block don't destory instantly.It delays several seconds to break.

Steps to Reproduce:

1.Obtain several block that can be destroyed instantly like tall_grass,tnt and so on.

2.Face to a face of block that can't be destroyed instantly like grass_block's top.{}

3.Left click and right click at same time,keeping for seconds{}

4(1).Stop before block breaks.

5(1)The Crack on block don't disappear instantly but exist several seconds

4(2)Don't Stop until block breaks.{}

5(2)The block don't destory instantly.It delays about 1 second to break.

Observed Behavior:

The Crack on block don't disappear instantly but exist several seconds

4(2)Don't Stop until block breaks or The block don't destory instantly.It delays about 1 second to break.{}

Expected Behavior:

The Crack on block disappears instantly when I stop Left clicking and right clicking.{}