end
function test_pagedown_often_shows_start_of_wrapping_line()
  -- draw a few lines ending in part of a wrapping line
  App.screen.init{width=50, height=60}
  Editor_state = edit.initialize_test_state()
  Editor_state.lines = load_array{'abc', 'def ghi jkl', 'mno'}
  Text.redraw_all(Editor_state)
  Editor_state.cursor1 = {line=1, pos=1}
  Editor_state.screen_top1 = {line=1, pos=1}
  Editor_state.screen_bottom1 = {}
  edit.draw(Editor_state, Text_color)
  local y = Editor_state.top
  App.screen.check(y, 'abc', 'baseline/screen:1')
  y = y + Editor_state.line_height
  App.screen.check(y, 'def ', 'baseline/screen:2')
  y = y + Editor_state.line_height
  App.screen.check(y, 'ghi ', 'baseline/screen:3')
  -- after pagedown we start drawing from the bottom _line_ (multiple screen lines)
  edit.run_after_keychord(Editor_state, 'pagedown')
  check_eq(Editor_state.screen_top1.line, 2, 'screen_top:line')
  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
  y = Editor_state.top
  App.screen.check(y, 'def ', 'screen:1')
  y = y + Editor_state.line_height
  App.screen.check(y, 'ghi ', 'screen:2')
  y = y + Editor_state.line_height
  App.screen.check(y, 'jkl', 'screen:3')

  -- If a line/paragraph gets to a page boundary, I often want to scroll
  -- before I get to the bottom.
  -- However, only do this if it makes forward progress.
  local bot2 = Text.to2(State, State.screen_bottom1)
  if bot2.screen_line > 1 then
    bot2.screen_line = math.max(bot2.screen_line-10, 1)
  end
  local new_top1 = Text.to1(State, bot2)
  if Text.lt1(State.screen_top1, new_top1) then
    State.screen_top1 = new_top1
  else
    State.screen_top1 = {line=State.screen_bottom1.line, pos=State.screen_bottom1.pos}
  end

  State.screen_top1 = {line=State.screen_bottom1.line, pos=State.screen_bottom1.pos}