[cairo] Copying of clip not working for PS surface

[Fred Kiefer]

Is anybody able to explain why the following short program gives the
output "Cairo status 'clip region not representable in desired format'
in copy clip"?

The same operations work fine when applied to an image surface.

Thank you
Fred

#include <stddef.h>
#include <cairo.h>
#include <cairo-ps.h>

int
main (int argc, const char *argv[])
{
  cairo_status_t status;
  cairo_t *ct;
  cairo_surface_t *surface;
  cairo_rectangle_list_t *clip_rects;

  surface = cairo_ps_surface_create("test.ps", 100, 100);
  status = cairo_surface_status(surface);
  if (status != CAIRO_STATUS_SUCCESS)
    {
      printf("Cairo status '%s' for surface\n",
cairo_status_to_string(status));
      return 0;
    }

  ct = cairo_create(surface);
  status = cairo_status(ct);
  if (status != CAIRO_STATUS_SUCCESS)
    {
      printf("Cairo status '%s' for context\n",
cairo_status_to_string(status));
      return 0;
    }

  cairo_rectangle(ct, 10, 10, 80, 80);
  cairo_clip(ct);
  clip_rects = cairo_copy_clip_rectangle_list(ct);
  status = clip_rects->status;
  if (status != CAIRO_STATUS_SUCCESS)
    {
      printf("Cairo status '%s' in copy clip\n",
cairo_status_to_string(status));
    }

  cairo_destroy(ct);
  cairo_surface_destroy(surface);
}