-
- /* Test results with out-of-range errnum and enough room. */
-
- buf[0] = '^';
- ret = strerror_r (0, buf, sizeof (buf));
- ASSERT (ret == 0 || ret == EINVAL);
- if (ret == 0)
- ASSERT (buf[0] != '^');
-
+ ASSERT (errno == 0);
+ ASSERT (strlen (buf) < sizeof buf);
+
+ /* POSIX requires strerror (0) to succeed. Reject use of "Unknown
+ error", but allow "Success", "No error", or even Solaris' "Error
+ 0" which are distinct patterns from true out-of-range strings.
+ http://austingroupbugs.net/view.php?id=382 */
+ errno = 0;
+ buf[0] = '\0';
+ ret = strerror_r (0, buf, sizeof buf);
+ ASSERT (ret == 0);
+ ASSERT (buf[0]);
+ ASSERT (errno == 0);
+ ASSERT (strstr (buf, "nknown") == NULL);
+ ASSERT (strstr (buf, "ndefined") == NULL);
+
+ /* Test results with out-of-range errnum and enough room. POSIX
+ allows an empty string on success, and allows an unchanged buf on
+ error, but these are not useful, so we guarantee contents. */
+ errno = 0;