Lexer: export default and child braces sometimes trigger “unexpected indentation”

[GeoffreyBooth]

Minimal case:

export default
  a: {
    b: 1
  }
  c: 2

[stdin]:5:1: error: unexpected indentation
  c: 2
^^

Interestingly, if export default is replaced with return, it compiles as expected.

If braces are added around the entire exported object (export default {...}), it also compiles; so that can be the workaround for anyone dealing with this right now. I stumbled across it because of trying to use an object spread in the object:

export default
  a: {
    b...
  }
  c: 2

Which requires braces around the b....