if(!(ret = platform_get_x_display()))
if((ret = platform_get_x_display())==0)
char *x11_display(const char *display) {    char *ret;    if(!display || !*display) {	/* try to find platform-specific local display */	if(!(ret = platform_get_x_display()))	    /* plausible default for all platforms */	    ret = dupstr(":0");    } else	ret = dupstr(display);    if(ret[0] == ':') {	/* no transport specified, use whatever we think is best */	char *s = dupcat(platform_x11_best_transport, ret, (char *)0);	sfree(ret);	return s;    } else	return ret;}