From e80b7e9ddefd6ec66ba736ef8ae2be312b0e16d3 Mon Sep 17 00:00:00 2001
From: Jeff Squyres <jsquyres@cisco.com>
Date: Wed, 25 Jul 2007 01:00:30 +0000
Subject: [PATCH] If MPI_ALLOC_MEM is invoked with a 0 sized request, return
 NULL.  If MPI_FREE_MEM is invoked with NULL, return success.

Fixes trac:1101.

This commit was SVN r15593.

The following Trac tickets were found above:
  Ticket 1101 --> https://svn.open-mpi.org/trac/ompi/ticket/1101
---
 ompi/mpi/c/alloc_mem.c | 14 ++++++++++++++
 ompi/mpi/c/free_mem.c  | 16 ++++++++--------
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/ompi/mpi/c/alloc_mem.c b/ompi/mpi/c/alloc_mem.c
index 4bb07ae852..8980b417cf 100644
--- a/ompi/mpi/c/alloc_mem.c
+++ b/ompi/mpi/c/alloc_mem.c
@@ -9,6 +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      Cisco, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -52,6 +53,19 @@ int MPI_Alloc_mem(MPI_Aint size, MPI_Info info, void *baseptr)
         }
     }
     
+    /* Per these threads:
+
+         http://www.open-mpi.org/community/lists/devel/2007/07/1977.php 
+         http://www.open-mpi.org/community/lists/devel/2007/07/1979.php         
+
+       If you call MPI_ALLOC_MEM with a size of 0, you get NULL
+       back .*/
+    if (0 == size) {
+        *((void **) baseptr) = NULL;
+        printf("0 size mem_alloc\n");
+        return MPI_SUCCESS;
+    }
+    
     *((void **) baseptr) = mca_mpool_base_alloc((size_t) size, info);
     if (NULL == *((void **) baseptr)) {
         return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_NO_MEM, 
diff --git a/ompi/mpi/c/free_mem.c b/ompi/mpi/c/free_mem.c
index 44b01f9d10..abb569bf46 100644
--- a/ompi/mpi/c/free_mem.c
+++ b/ompi/mpi/c/free_mem.c
@@ -9,6 +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      Cisco, Inc.  All rights reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -39,15 +40,14 @@ int MPI_Free_mem(void *baseptr)
 {
     OPAL_CR_TEST_CHECKPOINT_READY();
 
-    if (MPI_PARAM_CHECK) {
-        if (NULL == baseptr) {
-            return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_ARG,
-                                          FUNC_NAME);
-        }
-    }
+    /* Per these threads:
 
-    if(OMPI_SUCCESS != mca_mpool_base_free(baseptr))
-    {
+         http://www.open-mpi.org/community/lists/devel/2007/07/1977.php 
+         http://www.open-mpi.org/community/lists/devel/2007/07/1979.php         
+
+       If you call MPI_ALLOC_MEM with a size of 0, you get NULL
+       back.  So don't consider a NULL==baseptr an error. */
+    if (NULL != baseptr && OMPI_SUCCESS != mca_mpool_base_free(baseptr)) {
         return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_NO_MEM, FUNC_NAME);
     }