Interpreter segfaults trying to access instance variable

[ysbaddaden]

While trying out the interpreter I ran into a segfault that only happens with when interpreted. This is the furthest that I could reduce it.

abstract struct View
  @__io__ = uninitialized IO # also segfaults with IO|Nil

  def render(io : IO, &block) : Nil
    @__io__ = io
    template(&block)
  end

  def render(view : View, &block) : Nil
    view.render(@__io__, &block)
  end

  def will_segfault(&) : Nil
    p @__io__ # NOTE: segfault: invalid reference to @__io__
  end
end

struct Component < View
  def template(&)
    will_segfault {}
  end
end

struct Example < View
  def template(&)
    render(Component.new) do
      render(Component.new) {} # NOTE: removing this line prevents the segfault
    end
  end
end

Example.new.render(IO::Memory.new) {}