Correctly moves the pointers around on big data.

This commit was SVN r26259.

ompi/datatype/ompi_datatype.h

@@ -285,15 +285,17 @@ ompi_datatype_copy_content_same_ddt( const ompi_datatype_t* type, size_t count,
                                      char* pDestBuf, char* pSrcBuf )
 {
     int32_t length, rc;
+    OPAL_PTRDIFF_TYPE extent;
 
+    ompi_datatype_type_extent( type, &extent );
     while( 0 != count ) {
         length = INT_MAX;
         if( ((size_t)length) > count ) length = (int32_t)count;
         rc = opal_datatype_copy_content_same_ddt( &type->super, length,
                                                   pDestBuf, pSrcBuf );
         if( 0 != rc ) return rc;
-        pDestBuf += (ptrdiff_t)length;
-        pSrcBuf  += (ptrdiff_t)length;
+        pDestBuf += ((ptrdiff_t)length) * extent;
+        pSrcBuf  += ((ptrdiff_t)length) * extent;
         count -= (size_t)length;
     }
     return 0;