message: Fix smcup/rmcup toggle bug
  Resolves
diff: @@ -1736,7 +1736,9 @@ impl ansi::Handler for Term {
  match mode {
  ansi::Mode::SwapScreenAndSetRestoreCursor => {
  self.save_cursor_position();
  + if !self.alt {
  self.swap_alt();
  + }
  self.save_cursor_position();
  },
  ansi::Mode::ShowCursor => self.mode.insert(mode::SHOW_CURSOR),
  @@ -1763,7 +1765,9 @@ impl ansi::Handler for Term {
  match mode {
  ansi::Mode::SwapScreenAndSetRestoreCursor => {
  self.restore_cursor_position();
  + if self.alt {
  self.swap_alt();
  + }
  self.restore_cursor_position();
  },
  ansi::Mode::ShowCursor => self.mode.remove(mode::SHOW_CURSOR),
  