Prevent integer overflow in datatype creation. Patch based on

Gilles Gouaillardet solution attached to ticket #4145.

Closes trac:4145.
cmr=v1.7.4:reviewer=ompi-rm1.7
cmr=v1.6.6:reviewer=ompi-rm1.6

This commit was SVN r30342.

The following Trac tickets were found above:
  Ticket 4145 --> https://svn.open-mpi.org/trac/ompi/ticket/4145

ompi/datatype/ompi_datatype_create_darray.c

@@ -3,7 +3,7 @@
  * Copyright (c) 2004-2006 The Trustees of Indiana University and Indiana
  *                         University Research and Technology
  *                         Corporation.  All rights reserved.
- * Copyright (c) 2004-2013 The University of Tennessee and The University
+ * Copyright (c) 2004-2014 The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
  * Copyright (c) 2004-2006 High Performance Computing Center Stuttgart,
@@ -160,7 +160,7 @@ int32_t ompi_datatype_create_darray(int size,
                                     int const* gsize_array,
                                     int const* distrib_array,
                                     int const* darg_array,
-                                    int const* psize_array, 
+                                    int const* psize_array,
                                     int order,
                                     const ompi_datatype_t* oldtype,
                                     ompi_datatype_t** newtype)
@@ -250,9 +250,9 @@ int32_t ompi_datatype_create_darray(int size,
     /* set displacement and UB correctly. Use struct instead of
        resized for same reason as subarray */
     {
-        ptrdiff_t displs[3];
+        ptrdiff_t displs[3], tmp_size;
         ompi_datatype_t *types[3];
-        int tmp_size, blength[3] = { 1, 1, 1};
+        int blength[3] = { 1, 1, 1};
 
         displs[1] = st_offsets[start_loop];
         tmp_size = 1;

ompi/datatype/ompi_datatype_create_subarray.c

@@ -3,7 +3,7 @@
  * Copyright (c) 2004-2006 The Trustees of Indiana University and Indiana
  *                         University Research and Technology
  *                         Corporation.  All rights reserved.
- * Copyright (c) 2004-2013 The University of Tennessee and The University
+ * Copyright (c) 2004-2014 The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
  * Copyright (c) 2004-2006 High Performance Computing Center Stuttgart,
@@ -13,6 +13,8 @@
  * Copyright (c) 2009      Sun Microsystems, Inc. All rights reserved.
  * Copyright (c) 2009      Oak Ridge National Labs.  All rights reserved.
  * Copyright (c) 2010      Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2014      Research Organization for Information Science
+ *                         and Technology (RIST). All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -34,7 +36,7 @@ int32_t ompi_datatype_create_subarray(int ndims,
                                       const ompi_datatype_t* oldtype,
                                       ompi_datatype_t** newtype)
 {
-    MPI_Datatype last_type; 
+    MPI_Datatype last_type;
     int32_t i, step, end_loop;
     MPI_Aint size, displ, extent;
 
@@ -70,8 +72,8 @@ int32_t ompi_datatype_create_subarray(int ndims,
                                  oldtype, newtype );
 
     last_type = *newtype;
-    size = size_array[i] * size_array[i+step];
+    size = (MPI_Aint)size_array[i] * (MPI_Aint)size_array[i+step];
-    displ = start_array[i] + start_array[i+step] * size_array[i];
+    displ = (MPI_Aint)start_array[i] + (MPI_Aint)start_array[i+step] * (MPI_Aint)size_array[i];
     for( i += 2 * step; i != end_loop; i += step ) {
         ompi_datatype_create_hvector( subsize_array[i], 1, size * extent,
                                       last_type, newtype );
@@ -81,7 +83,7 @@ int32_t ompi_datatype_create_subarray(int ndims,
         last_type = *newtype;
     }
 
- replace_subarray_type:    
+ replace_subarray_type:
     /**
      * We cannot use resized here. Resized will only set the soft lb and ub markers
      * without moving the real data inside. What we need is to force the displacement