xcb tripping on unix sockets filename as hostname

gistfile1.txt

/* 
   Testing if "private/tmp/com.apple.launchd.EauNyeZmg1/org.macosforge.xquartz" is a valid display name

   For more information see:
   - http://www.x.org/releases/current/doc/libX11/libX11/libX11.html#XOpenDisplay
   - http://cgit.freedesktop.org/~chr/libxcb/tree/src/xcb_util.c
*/

#include <stdio.h>
#include <xcb/xcbext.h>

int
main(argv, argc) {
  char *display_name = "private/tmp/com.apple.launchd.EauNyeZmg1/org.macosforge.xquartz";
  char *host;
  int n = 0;
  int *screenp = NULL;
  // screenp
  xcb_parse_display(display_name, &host, &n, screenp);
  printf("display_name: %s\n", display_name);
  printf("host: %s\n", host);
}