+ /*
+ * Like close_nointr() but cannot fail. Guarantees errno is
+ * unchanged. Is a NOP with negative fds passed, and returns
+ * -1, so that it can be used in this syntax:
+ *
+ * fd = safe_close(fd);
+ */
+
+ if (fd >= 0) {
+ PROTECT_ERRNO;
+
+ /* The kernel might return pretty much any error code
+ * via close(), but the fd will be closed anyway. The
+ * only condition we want to check for here is whether
+ * the fd was invalid at all... */
+
+ assert_se(close_nointr(fd) != -EBADF);
+ }