rem: if (dry_run) return -1;
add: if (flags != O_RDONLY) { if (dry_run) return -1; CHECK_RO }
context: int do_open(char *pathname, int flags, mode_t mode){	if (dry_run) return -1;#ifdef O_BINARY	/* for Windows */	flags |= O_BINARY;#endif	CHECK_RO	return open(pathname, flags, mode);}