file.c:1494
static char *
strrdirsep(path)
    const char *path;
{
    char *last = NULL;
    while (*path) {
	if (isdirsep(*path)) {
	    const char *tmp = path++;
	    while (isdirsep(*path)) path++;
	    if (!*path) break;
	    last = (char *)tmp;
	}
	else {
	    path = CharNext(path);
	}
    }
    return last;
}
