bug#28873: 26.0.60; error while restoring frameset

[martin rudalics]

> While using the frameset--restore-frame function, it may happen that
> the modify-frame-parameters be called with a border-width which
> is not the default one for the current emacs. In this case,
> x_set_border_width errors because it can't change it.

'border-width' is in ‘frameset--initial-params’ and should be filtered
appropriately.  Can you provide a backtrace with a breakpoint in

  if (FRAME_X_WINDOW (f) != 0)
    error ("Cannot change the border width of a frame");

martin