+ msg = strerror (n);
+
+ /* Our strerror_r implementation might use the system's strerror
+ buffer, so all other clients of strerror have to see the error
+ copied into a buffer that we manage. This is not thread-safe,
+ even if the system strerror is, but portable programs shouldn't
+ be using strerror if they care about thread-safety. */
+ if (!msg || !*msg)