Bug#25344 Segmentation violation when try to run the perror utility

 - strerror might return NULL on some platforms


extra/perror.c:
  Backport fix from 5.0

extra/perror.c

@@ -217,8 +217,11 @@ int main(int argc,char *argv[])
       On some system, like NETWARE, strerror(unknown_error) returns a
       string 'Unknown Error'.  To avoid printing it we try to find the
       error string by asking for an impossible big error message.
+
+      On Solaris 2.8 it might return NULL
     */
-    msg= strerror(10000);
+    if ((msg= strerror(10000)) == NULL)
+      msg= "Unknown Error";
 
     /*
       Allocate a buffer for unknown_error since strerror always returns