[svn-r17306] Description:

	Stabilize file format changes for layout object header message and add
new "storage" object header message.  This version of the layout message
(& future ones) will contain the constant information for a dataset's layout
and the new storage message will contain information that can change over the
course of a dataset's lifetime.

Tested on:
        FreeBSD/32 6.3 (duty) in debug mode
        FreeBSD/64 6.3 (liberty) w/C++ & FORTRAN, in debug mode
        Linux/32 2.6 (jam) w/PGI compilers, w/C++ & FORTRAN, w/threadsafe,
                                in debug mode
        Linux/64-amd64 2.6 (smirom) w/Intel compilers w/default API=1.6.x,
                                w/C++ & FORTRAN, in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                                w/szip filter, in production mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                                in production mode
        Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in debug mode
        Linux/64-amd64 2.6 (abe) w/parallel, w/FORTRAN, in production mode
        Mac OS X/32 10.5.7 (amazon) in debug mode
        Mac OS X/32 10.5.7 (amazon) w/C++ & FORTRAN, w/threadsafe,
                                in production mode

1 files changed, 13 insertions, 0 deletions

diff --git a/src/H5Doh.c b/src/H5Doh.c
index d2649f7..e1d9827 100644
--- a/src/H5Doh.c
+++ b/src/H5Doh.c
@@ -155,6 +155,10 @@ H5O_dset_free_copy_file_udata(void *_udata)
     if(udata->src_pline)
         H5O_msg_free(H5O_PLINE_ID, udata->src_pline);
 
+    /* Release copy of dataset's layout, if it was set */
+    if(udata->src_layout)
+        H5O_msg_free(H5O_LAYOUT_ID, udata->src_layout);
+
     /* Release space for 'copy file' user data */
     (void)H5FL_FREE(H5D_copy_file_ud_t, udata);
 
@@ -375,6 +379,15 @@ H5O_dset_bh_info(H5F_t *f, hid_t dxpl_id, H5O_t *oh, H5_ih_info_t *bh_info)
     if(NULL == H5O_msg_read_oh(f, dxpl_id, oh, H5O_LAYOUT_ID, &layout))
 	HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't find layout message")
 
+    /* Check for newer version of the layout message, which indicates that some
+     * information is stored in the 'storage' message.
+     */
+    if(layout.version >= H5O_LAYOUT_VERSION_4) {
+        /* Retrieve the storage information */
+        if(NULL == H5O_msg_read_oh(f, dxpl_id, oh, H5O_STORAGE_ID, &(layout.storage)))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "unable to read data storage message")
+    } /* end if */
+
     /* Check for chunked dataset storage */
     if(layout.type == H5D_CHUNKED && H5D_chunk_is_space_alloc(&layout.storage)) {
         H5O_pline_t pline;              /* I/O pipeline message */