Non-idempotence with Haddock comment before deriving clause

[amesgen]

This snippet (minimized from here) is non-idempotent:

data A = A
  -- | B
  deriving (Eq)

to

data A = A
  deriving (-- | B
            Eq)

to

data A = A
  deriving
    ( -- | B
      Eq
    )

Expected behavior Formatting should be idempotent, but this case is tricky as the comment is an "accidental" Haddock comment (a constructor variant is commented out).

Environment Ormolu 0.2.0.0