Air can be used in custom recipes, causing a crash

The bug

You can use minecraft:air as recipe input and output; using it as output then clicking on this recipe will crash the game.

How to reproduce

Create a recipe using air (as input or output).

Examples:

{
  "type": "crafting_shapeless",
  "ingredients": [
    {
     "item": "air"
    }
  ],
  "result": {
    "item": "diamond"
  }
}

Recipe for crafting diamond out of 1 air

{
  "type": "crafting_shapeless",
  "ingredients": [
    {
     "item": "diamond"
    }
  ],
  "result": {
    "item": "air"
  }
}

Recipe for crafting air out of 1 diamond.