Add some comments to reinforce the fact that MPI applications should not be using the non-public members of ompi_status_public_t. Refs trac:2241.

This commit was SVN r23471.

The following Trac tickets were found above:
  Ticket 2241 --> https://svn.open-mpi.org/trac/ompi/ticket/2241

ompi/include/mpi.h.in

@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2007-2009 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2007-2010 Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2008-2009 Sun Microsystems, Inc.  All rights reserved.
  * Copyright (c) 2009      Oak Ridge National Labs.  All rights reserved.
  * $COPYRIGHT$
@@ -320,11 +320,17 @@ typedef struct ompi_win_t *MPI_Win;
  * MPI_Status
  */
 struct ompi_status_public_t {
-  int MPI_SOURCE;
-  int MPI_TAG;
-  int MPI_ERROR;
-  int _cancelled;
-  size_t _ucount;  /* This field has to be correctly aligned */
+    /* These fields are publicly defined in the MPI specification.
+       User applications may freely read from these fields. */
+    int MPI_SOURCE;
+    int MPI_TAG;
+    int MPI_ERROR;
+    /* The following two fields are internal to the Open MPI
+       implementation and should not be accessed by MPI applications.
+       They are subject to change at any time.  These are not the
+       droids you're looking for. */
+    int _cancelled;
+    size_t _ucount;
 };
 typedef struct ompi_status_public_t ompi_status_public_t;