[svn-r13240] Description:

	More cleanups on the object header message handling code, to make it
easier to work with and move forward on the creation order coding.

	Various other minor cleanups & warning fixes.

Tested on:
	FreeBSD/32 6.2 (duty)

36 files changed, 306 insertions, 399 deletions

diff --git a/src/H5Adense.c b/src/H5Adense.c
index b630166..f227730 100644
--- a/src/H5Adense.c
+++ b/src/H5Adense.c
@@ -1091,7 +1091,7 @@ H5A_dense_remove_bt2_cb(const void *_record, void *_bt2_udata)
     else {
         /* Perform the deletion action on the attribute */
         /* (takes care of shared & committed datatype/dataspace components) */
-        if(H5O_attr_delete(bt2_udata->f, bt2_udata->dxpl_id, *(H5A_t **)bt2_udata->found_op_data, TRUE) < 0)
+        if(H5O_attr_delete(bt2_udata->f, bt2_udata->dxpl_id, *(H5A_t **)bt2_udata->found_op_data) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
         /* Remove record from fractal heap */
@@ -1327,7 +1327,7 @@ H5A_dense_delete_bt2_cb(const void *_record, void *_bt2_udata)
     else {
         /* Perform the deletion action on the attribute */
         /* (takes care of shared/committed datatype & dataspace components) */
-        if(H5O_attr_delete(bt2_udata->f, bt2_udata->dxpl_id, fh_udata.attr, TRUE) < 0)
+        if(H5O_attr_delete(bt2_udata->f, bt2_udata->dxpl_id, fh_udata.attr) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
     } /* end else */
 
diff --git a/src/H5Apkg.h b/src/H5Apkg.h
index 9ac95cb..7f95a70 100644
--- a/src/H5Apkg.h
+++ b/src/H5Apkg.h
@@ -193,7 +193,7 @@ H5_DLL herr_t H5A_attr_release_table(H5A_attr_table_t *atable);
 
 /* Attribute object header routines */
 H5_DLL herr_t H5O_attr_reset(void *_mesg);
-H5_DLL herr_t H5O_attr_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link);
+H5_DLL herr_t H5O_attr_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg);
 H5_DLL herr_t H5O_attr_link(H5F_t *f, hid_t dxpl_id, const void *_mesg);
 
 /* Attribute operations */
diff --git a/src/H5D.c b/src/H5D.c
index b49d88a..fa7b19c 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -1761,7 +1761,7 @@ H5D_open_oid(H5D_t *dataset, hid_t dxpl_id)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTOPENOBJ, FAIL, "unable to open")
 
     /* Get the type and space */
-    if(NULL == (dataset->shared->type = H5O_msg_read(&(dataset->oloc), H5O_DTYPE_ID, 0, NULL, dxpl_id)))
+    if(NULL == (dataset->shared->type = H5O_msg_read(&(dataset->oloc), H5O_DTYPE_ID, NULL, dxpl_id)))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to load type info from dataset header")
     if(NULL == (dataset->shared->space = H5S_read(&(dataset->oloc), dxpl_id)))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to load space info from dataset header")
@@ -1776,7 +1776,7 @@ H5D_open_oid(H5D_t *dataset, hid_t dxpl_id)
 
     /* Get the optional filters message */
     pline = &dataset->shared->dcpl_cache.pline;
-    if(NULL != H5O_msg_read(&(dataset->oloc), H5O_PLINE_ID, 0, pline, dxpl_id)) {
+    if(NULL != H5O_msg_read(&(dataset->oloc), H5O_PLINE_ID, pline, dxpl_id)) {
         if(H5P_set(plist, H5D_CRT_DATA_PIPELINE_NAME, pline) < 0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set pipeline")
     } /* end if */
@@ -1789,7 +1789,7 @@ H5D_open_oid(H5D_t *dataset, hid_t dxpl_id)
      * values are copied to the dataset create plist so the user can query
      * them.
      */
-    if(NULL == H5O_msg_read(&(dataset->oloc), H5O_LAYOUT_ID, 0, &(dataset->shared->layout), dxpl_id))
+    if(NULL == H5O_msg_read(&(dataset->oloc), H5O_LAYOUT_ID, &(dataset->shared->layout), dxpl_id))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to read data layout message")
     if(H5P_set(plist, H5D_CRT_LAYOUT_NAME, &dataset->shared->layout.type) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set layout")
@@ -1854,11 +1854,11 @@ H5D_open_oid(H5D_t *dataset, hid_t dxpl_id)
     fill_prop = &dataset->shared->dcpl_cache.fill;
 
     /* Try to get the new fill value message from the object header */
-    if(NULL == H5O_msg_read(&(dataset->oloc), H5O_FILL_NEW_ID, 0, fill_prop, dxpl_id)) {
+    if(NULL == H5O_msg_read(&(dataset->oloc), H5O_FILL_NEW_ID, fill_prop, dxpl_id)) {
         H5E_clear_stack(NULL);
 
 	/* For backward compatibility, try to retrieve the old fill value message */
-        if(NULL == H5O_msg_read(&(dataset->oloc), H5O_FILL_ID, 0, fill_prop, dxpl_id)) {
+        if(NULL == H5O_msg_read(&(dataset->oloc), H5O_FILL_ID, fill_prop, dxpl_id)) {
             H5E_clear_stack(NULL);
 
             /* Set the space allocation time appropriately, based on the type of dataset storage */
@@ -1902,7 +1902,7 @@ H5D_open_oid(H5D_t *dataset, hid_t dxpl_id)
      * also undefined when space allocate time is H5D_ALLOC_TIME_LATE. */
     if((dataset->shared->layout.type == H5D_CONTIGUOUS && !H5F_addr_defined(dataset->shared->layout.u.contig.addr))
             || (dataset->shared->layout.type == H5D_CHUNKED && !H5F_addr_defined(dataset->shared->layout.u.chunk.addr))) {
-        if(NULL != H5O_msg_read(&(dataset->oloc), H5O_EFL_ID, 0, &dataset->shared->dcpl_cache.efl, dxpl_id)) {
+        if(NULL != H5O_msg_read(&(dataset->oloc), H5O_EFL_ID, &dataset->shared->dcpl_cache.efl, dxpl_id)) {
             if(H5P_set(plist, H5D_CRT_EXT_FILE_LIST_NAME, &dataset->shared->dcpl_cache.efl) < 0)
             	HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set external file list")
 
@@ -2012,7 +2012,7 @@ H5D_close(H5D_t *dataset)
             case H5D_COMPACT:
                 /* Update header message of layout for compact dataset. */
                 if(dataset->shared->layout.u.compact.dirty) {
-                    if(H5O_msg_write(&(dataset->oloc), H5O_LAYOUT_ID, 0, 0, H5O_UPDATE_TIME, &(dataset->shared->layout), H5AC_dxpl_id) < 0)
+                    if(H5O_msg_write(&(dataset->oloc), H5O_LAYOUT_ID, 0, H5O_UPDATE_TIME, &(dataset->shared->layout), H5AC_dxpl_id) < 0)
                         HGOTO_ERROR(H5E_DATASET, H5E_CANTRELEASE, FAIL, "unable to update layout message")
                     dataset->shared->layout.u.compact.dirty = FALSE;
                 } /* end if */
@@ -2403,7 +2403,7 @@ H5D_alloc_storage(H5F_t *f, hid_t dxpl_id, H5D_t *dset/*in,out*/, H5D_time_alloc
          * set the address.  (this is improves forward compatibility).
          */
         if(time_alloc != H5D_ALLOC_CREATE && addr_set)
-            if(H5O_msg_write(&dset->oloc, H5O_LAYOUT_ID, 0, H5O_MSG_FLAG_CONSTANT, update_time, &dset->shared->layout, dxpl_id) < 0)
+            if(H5O_msg_write(&dset->oloc, H5O_LAYOUT_ID, H5O_MSG_FLAG_CONSTANT, update_time, &dset->shared->layout, dxpl_id) < 0)
                 HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update layout message")
     } /* end if */
 
@@ -3306,7 +3306,7 @@ H5D_flush(const H5F_t *f, hid_t dxpl_id, unsigned flags)
 
                 case H5D_COMPACT:
                     if(dataset->shared->layout.u.compact.dirty) {
-                        if(H5O_msg_write(&(dataset->oloc), H5O_LAYOUT_ID, 0, 0, H5O_UPDATE_TIME, &(dataset->shared->layout), dxpl_id) < 0)
+                        if(H5O_msg_write(&(dataset->oloc), H5O_LAYOUT_ID, 0, H5O_UPDATE_TIME, &(dataset->shared->layout), dxpl_id) < 0)
                             HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to update layout message")
                         dataset->shared->layout.u.compact.dirty = FALSE;
                     } /* end if */
diff --git a/src/H5Doh.c b/src/H5Doh.c
index 5c8797e..3cfc783 100644
--- a/src/H5Doh.c
+++ b/src/H5Doh.c
@@ -177,13 +177,13 @@ H5O_dset_isa(H5O_t *oh)
     HDassert(oh);
 
     /* Datatype */
-    if((exists = H5O_msg_exists_oh(oh, H5O_DTYPE_ID, 0)) < 0)
+    if((exists = H5O_msg_exists_oh(oh, H5O_DTYPE_ID)) < 0)
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to read object header")
     else if(!exists)
 	HGOTO_DONE(FALSE)
 
     /* Layout */
-    if((exists = H5O_msg_exists_oh(oh, H5O_SDSPACE_ID, 0)) < 0)
+    if((exists = H5O_msg_exists_oh(oh, H5O_SDSPACE_ID)) < 0)
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to read object header")
     else if(!exists)
 	HGOTO_DONE(FALSE)
diff --git a/src/H5FD.c b/src/H5FD.c
index a2e0cb1..97be6b9 100644
--- a/src/H5FD.c
+++ b/src/H5FD.c
@@ -2942,7 +2942,7 @@ H5FDset_eoa(H5FD_t *file, H5FD_mem_t type, haddr_t addr)
     if(!file || !file->cls)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid file pointer")
     if(type<H5FD_MEM_DEFAULT || type >= H5FD_MEM_NTYPES)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, HADDR_UNDEF, "invalid file type")
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid file type")
 
     if(!H5F_addr_defined(addr) || addr>file->maxaddr)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid end-of-address value")
diff --git a/src/H5G.c b/src/H5G.c
index 602db88..588e923 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -539,13 +539,13 @@ H5Gget_create_plist(hid_t group_id)
         HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't get object creation info")
 
     /* Check for the group having a group info message */
-    if((ginfo_exists = H5O_msg_exists(&(grp->oloc), H5O_GINFO_ID, 0, H5AC_ind_dxpl_id)) < 0)
+    if((ginfo_exists = H5O_msg_exists(&(grp->oloc), H5O_GINFO_ID, H5AC_ind_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(ginfo_exists) {
         H5O_ginfo_t ginfo;		/* Group info message            */
 
         /* Read the group info */
-        if(NULL == H5O_msg_read(&(grp->oloc), H5O_GINFO_ID, 0, &ginfo, H5AC_ind_dxpl_id))
+        if(NULL == H5O_msg_read(&(grp->oloc), H5O_GINFO_ID, &ginfo, H5AC_ind_dxpl_id))
             HGOTO_ERROR(H5E_SYM, H5E_BADMESG, FAIL, "can't get group info")
 
         /* Set the group info for the property list */
@@ -554,13 +554,13 @@ H5Gget_create_plist(hid_t group_id)
     } /* end if */
 
     /* Check for the group having a link info message */
-    if((linfo_exists = H5O_msg_exists(&(grp->oloc), H5O_LINFO_ID, 0, H5AC_ind_dxpl_id)) < 0)
+    if((linfo_exists = H5O_msg_exists(&(grp->oloc), H5O_LINFO_ID, H5AC_ind_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(linfo_exists) {
         H5O_linfo_t linfo;		/* Link info message            */
 
         /* Read the link info */
-        if(NULL == H5O_msg_read(&(grp->oloc), H5O_LINFO_ID, 0, &linfo, H5AC_ind_dxpl_id))
+        if(NULL == H5O_msg_read(&(grp->oloc), H5O_LINFO_ID, &linfo, H5AC_ind_dxpl_id))
             HGOTO_ERROR(H5E_SYM, H5E_BADMESG, FAIL, "can't get link info")
 
         /* Set the link info for the property list */
@@ -1285,8 +1285,8 @@ H5G_open_oid(H5G_t *grp, hid_t dxpl_id)
     obj_opened = TRUE;
 
     /* Check if this object has the right message(s) to be treated as a group */
-    if((H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, 0, dxpl_id) <= 0)
-            && (H5O_msg_exists(&(grp->oloc), H5O_LINFO_ID, 0, dxpl_id) <= 0))
+    if((H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, dxpl_id) <= 0)
+            && (H5O_msg_exists(&(grp->oloc), H5O_LINFO_ID, dxpl_id) <= 0))
         HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "not a group")
 
 done:
diff --git a/src/H5Gdense.c b/src/H5Gdense.c
index abc7fcc..4da0be4 100644
--- a/src/H5Gdense.c
+++ b/src/H5Gdense.c
@@ -118,7 +118,6 @@ typedef struct {
 typedef struct {
     /* downward */
     H5G_bt2_ud_common_t common;         /* Common info for B-tree user data (must be first) */
-    hbool_t     adj_link;               /* Whether to adjust link count on object */
     hbool_t     rem_from_fheap;         /* Whether to remove the link from the fractal heap */
     hbool_t     rem_from_corder_index;  /* Whether to remove the link from the creation order index */
     haddr_t     corder_bt2_addr;        /* Address of v2 B-tree indexing creation order */
@@ -134,7 +133,6 @@ typedef struct {
     /* downward */
     H5F_t       *f;                     /* Pointer to file that fractal heap is in */
     hid_t       dxpl_id;                /* DXPL for operation                */
-    hbool_t     adj_link;               /* Whether to adjust link count on object */
     hbool_t     rem_from_corder_index;  /* Whether to remove the link from the creation order index */
     haddr_t     corder_bt2_addr;        /* Address of v2 B-tree indexing creation order */
     H5RS_str_t *grp_full_path_r;        /* Full path of group where link is removed */
@@ -1367,9 +1365,9 @@ H5G_dense_remove_fh_cb(const void *obj, size_t UNUSED obj_len, void *_udata)
         if(H5G_link_name_replace(udata->f, udata->dxpl_id, udata->grp_full_path_r, lnk->name, lnk->type, lnk->u.hard.addr) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTRENAME, FAIL, "unable to rename open objects")
 
-    /* Perform the deletion action on the link */
+    /* Perform the deletion action on the link, if requested */
     /* (call message "delete" callback directly: *ick* - QAK) */
-    if(H5O_link_delete(udata->f, udata->dxpl_id, lnk, udata->adj_link) < 0)
+    if(H5O_link_delete(udata->f, udata->dxpl_id, lnk) < 0)
         HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to delete link")
 
 done:
@@ -1407,7 +1405,6 @@ H5G_dense_remove_bt2_cb(const void *_record, void *_bt2_udata)
     /* Set up the user data for fractal heap 'op' callback */
     fh_udata.f = bt2_udata->common.f;
     fh_udata.dxpl_id = bt2_udata->common.dxpl_id;
-    fh_udata.adj_link = bt2_udata->adj_link;
     fh_udata.rem_from_corder_index = bt2_udata->rem_from_corder_index;
     fh_udata.corder_bt2_addr = bt2_udata->corder_bt2_addr;
     fh_udata.grp_full_path_r = bt2_udata->grp_full_path_r;
@@ -1470,7 +1467,6 @@ H5G_dense_remove(H5F_t *f, hid_t dxpl_id, const H5O_linfo_t *linfo,
     udata.common.name_hash = H5_checksum_lookup3(name, HDstrlen(name), 0);
     udata.common.found_op = NULL;
     udata.common.found_op_data = NULL;
-    udata.adj_link = TRUE;
     udata.rem_from_fheap = TRUE;
     udata.rem_from_corder_index = H5F_addr_defined(linfo->corder_bt2_addr);
     udata.corder_bt2_addr = linfo->corder_bt2_addr;
@@ -1478,8 +1474,7 @@ H5G_dense_remove(H5F_t *f, hid_t dxpl_id, const H5O_linfo_t *linfo,
     udata.replace_names = TRUE;
 
     /* Remove the record from the name index v2 B-tree */
-    if(H5B2_remove(f, dxpl_id, H5G_BT2_NAME, linfo->name_bt2_addr,
-            &udata, H5G_dense_remove_bt2_cb, &udata) < 0)
+    if(H5B2_remove(f, dxpl_id, H5G_BT2_NAME, linfo->name_bt2_addr, &udata, H5G_dense_remove_bt2_cb, &udata) < 0)
         HGOTO_ERROR(H5E_SYM, H5E_CANTREMOVE, FAIL, "unable to remove link from name index v2 B-tree")
 
 done:
@@ -1616,7 +1611,7 @@ H5G_dense_remove_by_idx_bt2_cb(const void *_record, void *_bt2_udata)
 
     /* Perform the deletion action on the link */
     /* (call link message "delete" callback directly: *ick* - QAK) */
-    if(H5O_link_delete(bt2_udata->f, bt2_udata->dxpl_id, fh_udata.lnk, TRUE) < 0)
+    if(H5O_link_delete(bt2_udata->f, bt2_udata->dxpl_id, fh_udata.lnk) < 0)
         HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to delete link")
 
     /* Release the space allocated for the link */
@@ -1781,7 +1776,6 @@ H5G_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_linfo_t *linfo, hbool_t adj_link)
         udata.common.name_hash = 0;
         udata.common.found_op = NULL;
         udata.common.found_op_data = NULL;
-        udata.adj_link = TRUE;
         udata.rem_from_fheap = FALSE;           /* handled in "bulk" below by deleting entire heap */
         udata.rem_from_corder_index = FALSE;
         udata.grp_full_path_r = NULL;
diff --git a/src/H5Gdeprec.c b/src/H5Gdeprec.c
index 108e48c..8a6676b 100644
--- a/src/H5Gdeprec.c
+++ b/src/H5Gdeprec.c
@@ -670,7 +670,7 @@ H5G_get_comment(H5G_loc_t *loc, const char *name, size_t bufsize, char *buf, hid
 
     /* Get the message */
     comment.s = NULL;
-    if(NULL == H5O_msg_read(obj_loc.oloc, H5O_NAME_ID, 0, &comment, dxpl_id)) {
+    if(NULL == H5O_msg_read(obj_loc.oloc, H5O_NAME_ID, &comment, dxpl_id)) {
 	if(buf && bufsize > 0)
             buf[0] = '\0';
 	ret_value = 0;
diff --git a/src/H5Gnode.c b/src/H5Gnode.c
index 0c23524..ee22ef2 100644
--- a/src/H5Gnode.c
+++ b/src/H5Gnode.c
@@ -1276,8 +1276,8 @@ H5G_node_remove(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_lt_key/*in,out*/,
         if(H5G_link_name_replace(f, dxpl_id, udata->grp_full_path_r, s, lnk_type, lnk_addr) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "unable to get object type")
 
-        /* Decrement the ref. count for hard links, if requested */
-        if(lnk_type == H5L_TYPE_HARD && udata->adj_link) {
+        /* Decrement the ref. count for hard links */
+        if(lnk_type == H5L_TYPE_HARD) {
             H5O_loc_t tmp_oloc;             /* Temporary object location */
 
             /* Build temporary object location */
@@ -1359,14 +1359,12 @@ H5G_node_remove(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_lt_key/*in,out*/,
         /* Reduce the link count for all entries in this node */
         for(idx = 0; idx < sn->nsyms; idx++) {
             if(!(H5G_CACHED_SLINK == sn->entry[idx].type)) {
-                /* Decrement the reference count, if requested */
-                if(udata->adj_link) {
-                    HDassert(H5F_addr_defined(sn->entry[idx].header));
-                    tmp_oloc.addr = sn->entry[idx].header;
+                /* Decrement the reference count */
+                HDassert(H5F_addr_defined(sn->entry[idx].header));
+                tmp_oloc.addr = sn->entry[idx].header;
 
-                    if(H5O_link(&tmp_oloc, -1, dxpl_id) < 0)
-                        HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, H5B_INS_ERROR, "unable to decrement object link count")
-                } /* end if */
+                if(H5O_link(&tmp_oloc, -1, dxpl_id) < 0)
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, H5B_INS_ERROR, "unable to decrement object link count")
             } /* end if */
         } /* end for */
 
diff --git a/src/H5Gobj.c b/src/H5Gobj.c
index 189adf9..fe0f99e 100644
--- a/src/H5Gobj.c
+++ b/src/H5Gobj.c
@@ -413,14 +413,14 @@ H5G_obj_insert(H5O_loc_t *grp_oloc, const char *name, H5O_link_t *obj_lnk,
 
     /* Check if we have information about the number of objects in this group */
     /* (by attempting to get the link info message for this group) */
-    if(H5O_msg_read(grp_oloc, H5O_LINFO_ID, 0, &linfo, dxpl_id)) {
+    if(H5O_msg_read(grp_oloc, H5O_LINFO_ID, &linfo, dxpl_id)) {
         size_t link_msg_size;   /* Size of new link message in the file */
 
         /* Using the new format for groups */
         use_old_format = FALSE;
 
         /* Get the group info */
-        if(NULL == H5O_msg_read(grp_oloc, H5O_GINFO_ID, 0, &ginfo, dxpl_id))
+        if(NULL == H5O_msg_read(grp_oloc, H5O_GINFO_ID, &ginfo, dxpl_id))
             HGOTO_ERROR(H5E_SYM, H5E_BADMESG, FAIL, "can't get group info")
 
         /* Check for tracking creation order on this group's links */
@@ -541,7 +541,7 @@ H5G_obj_insert(H5O_loc_t *grp_oloc, const char *name, H5O_link_t *obj_lnk,
     /* Increment the number of objects in this group */
     if(!use_old_format) {
         linfo.nlinks++;
-        if(H5O_msg_write(grp_oloc, H5O_LINFO_ID, 0, 0, H5O_UPDATE_TIME, &linfo, dxpl_id) < 0)
+        if(H5O_msg_write(grp_oloc, H5O_LINFO_ID, 0, H5O_UPDATE_TIME, &linfo, dxpl_id) < 0)
             HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, FAIL, "can't update link info message")
     } /* end if */
 
@@ -606,7 +606,7 @@ H5G_obj_iterate(hid_t loc_id, const char *group_name,
         HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "bad group ID")
 
     /* Attempt to get the link info for this group */
-    if(H5O_msg_read(&(grp->oloc), H5O_LINFO_ID, 0, &linfo, dxpl_id)) {
+    if(H5O_msg_read(&(grp->oloc), H5O_LINFO_ID, &linfo, dxpl_id)) {
         /* Check for going out of bounds */
         if(skip > 0 && (size_t)skip >= linfo.nlinks)
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "index out of bound")
@@ -616,7 +616,7 @@ H5G_obj_iterate(hid_t loc_id, const char *group_name,
             H5O_ginfo_t ginfo;		        /* Group info message */
 
             /* Get group info message, to see if creation order is tracked for links in this group */
-            if(NULL == H5O_msg_read(&(grp->oloc), H5O_GINFO_ID, 0, &ginfo, dxpl_id))
+            if(NULL == H5O_msg_read(&(grp->oloc), H5O_GINFO_ID, &ginfo, dxpl_id))
                 HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info message for group")
 
             /* Check if creation order is tracked */
@@ -682,7 +682,7 @@ H5G_obj_info(H5O_loc_t *oloc, H5G_info_t *grp_info, hid_t dxpl_id)
     HDassert(grp_info);
 
     /* Attempt to get the link info for this group */
-    if(H5O_msg_read(oloc, H5O_LINFO_ID, 0, &linfo, dxpl_id)) {
+    if(H5O_msg_read(oloc, H5O_LINFO_ID, &linfo, dxpl_id)) {
         /* Retrieve the information about the links */
         grp_info->nlinks = linfo.nlinks;
         grp_info->min_corder = linfo.min_corder;
@@ -740,13 +740,13 @@ H5G_obj_get_name_by_idx(H5O_loc_t *oloc, H5_index_t idx_type,
     HDassert(oloc && oloc->file);
 
     /* Attempt to get the link info for this group */
-    if(H5O_msg_read(oloc, H5O_LINFO_ID, 0, &linfo, dxpl_id)) {
+    if(H5O_msg_read(oloc, H5O_LINFO_ID, &linfo, dxpl_id)) {
         /* Check for creation order tracking, if creation order index lookup requested */
         if(idx_type == H5_INDEX_CRT_ORDER) {
             H5O_ginfo_t ginfo;		        /* Group info message */
 
             /* Get group info message, to see if creation order is tracked for links in this group */
-            if(NULL == H5O_msg_read(oloc, H5O_GINFO_ID, 0, &ginfo, dxpl_id))
+            if(NULL == H5O_msg_read(oloc, H5O_GINFO_ID, &ginfo, dxpl_id))
                 HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info message for group")
 
             /* Check if creation order is tracked */
@@ -811,7 +811,7 @@ H5G_obj_get_type_by_idx(H5O_loc_t *oloc, hsize_t idx, hid_t dxpl_id)
     HDassert(oloc);
 
     /* Attempt to get the link info for this group */
-    if(H5O_msg_read(oloc, H5O_LINFO_ID, 0, &linfo, dxpl_id)) {
+    if(H5O_msg_read(oloc, H5O_LINFO_ID, &linfo, dxpl_id)) {
         if(H5F_addr_defined(linfo.link_fheap_addr)) {
             /* Get the object's name from the dense link storage */
             if((ret_value = H5G_dense_get_type_by_idx(oloc->file, dxpl_id, &linfo, idx)) < 0)
@@ -881,7 +881,7 @@ H5G_obj_remove_update_linfo(H5O_loc_t *oloc, H5O_linfo_t *linfo, hid_t dxpl_id)
             H5O_ginfo_t ginfo;		/* Group info message            */
 
             /* Get the group info */
-            if(NULL == H5O_msg_read(oloc, H5O_GINFO_ID, 0, &ginfo, dxpl_id))
+            if(NULL == H5O_msg_read(oloc, H5O_GINFO_ID, &ginfo, dxpl_id))
                 HGOTO_ERROR(H5E_SYM, H5E_BADMESG, FAIL, "can't get group info")
 
             /* Check if we should switch from dense storage back to link messages */
@@ -940,7 +940,7 @@ H5G_obj_remove_update_linfo(H5O_loc_t *oloc, H5O_linfo_t *linfo, hid_t dxpl_id)
     } /* end if */
 
     /* Update link info in the object header */
-    if(H5O_msg_write(oloc, H5O_LINFO_ID, 0, 0, H5O_UPDATE_TIME, linfo, dxpl_id) < 0)
+    if(H5O_msg_write(oloc, H5O_LINFO_ID, 0, H5O_UPDATE_TIME, linfo, dxpl_id) < 0)
         HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, FAIL, "can't update link info message")
 
 done:
@@ -975,7 +975,7 @@ H5G_obj_remove(H5O_loc_t *oloc, H5RS_str_t *grp_full_path_r, const char *name, h
     HDassert(name && *name);
 
     /* Attempt to get the link info for this group */
-    if(H5O_msg_read(oloc, H5O_LINFO_ID, 0, &linfo, dxpl_id)) {
+    if(H5O_msg_read(oloc, H5O_LINFO_ID, &linfo, dxpl_id)) {
         /* Using the new format for groups */
         use_old_format = FALSE;
 
@@ -1040,13 +1040,13 @@ H5G_obj_remove_by_idx(H5O_loc_t *grp_oloc, H5RS_str_t *grp_full_path_r,
     HDassert(grp_oloc && grp_oloc->file);
 
     /* Attempt to get the link info for this group */
-    if(H5O_msg_read(grp_oloc, H5O_LINFO_ID, 0, &linfo, dxpl_id)) {
+    if(H5O_msg_read(grp_oloc, H5O_LINFO_ID, &linfo, dxpl_id)) {
         /* Check for creation order tracking, if creation order index lookup requested */
         if(idx_type == H5_INDEX_CRT_ORDER) {
             H5O_ginfo_t ginfo;		        /* Group info message */
 
             /* Get group info message, to see if creation order is tracked for links in this group */
-            if(NULL == H5O_msg_read(grp_oloc, H5O_GINFO_ID, 0, &ginfo, dxpl_id))
+            if(NULL == H5O_msg_read(grp_oloc, H5O_GINFO_ID, &ginfo, dxpl_id))
                 HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info message for group")
 
             /* Check if creation order is tracked */
@@ -1123,7 +1123,7 @@ H5G_obj_lookup(H5O_loc_t *grp_oloc, const char *name, H5O_link_t *lnk,
     HDassert(name && *name);
 
     /* Attempt to get the link info message for this group */
-    if(H5O_msg_read(grp_oloc, H5O_LINFO_ID, 0, &linfo, dxpl_id)) {
+    if(H5O_msg_read(grp_oloc, H5O_LINFO_ID, &linfo, dxpl_id)) {
         /* Check for dense link storage */
         if(H5F_addr_defined(linfo.link_fheap_addr)) {
             /* Get the object's info from the dense link storage */
@@ -1177,13 +1177,13 @@ H5G_obj_lookup_by_idx(H5O_loc_t *grp_oloc, H5_index_t idx_type,
     HDassert(grp_oloc && grp_oloc->file);
 
     /* Attempt to get the link info message for this group */
-    if(H5O_msg_read(grp_oloc, H5O_LINFO_ID, 0, &linfo, dxpl_id)) {
+    if(H5O_msg_read(grp_oloc, H5O_LINFO_ID, &linfo, dxpl_id)) {
         /* Check for creation order tracking, if creation order index lookup requested */
         if(idx_type == H5_INDEX_CRT_ORDER) {
             H5O_ginfo_t ginfo;		        /* Group info message */
 
             /* Get group info message, to see if creation order is tracked for links in this group */
-            if(NULL == H5O_msg_read(grp_oloc, H5O_GINFO_ID, 0, &ginfo, dxpl_id))
+            if(NULL == H5O_msg_read(grp_oloc, H5O_GINFO_ID, &ginfo, dxpl_id))
                 HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve group info message for group")
 
             /* Check if creation order is tracked */
diff --git a/src/H5Goh.c b/src/H5Goh.c
index 2b51d0a..dc8c19b 100644
--- a/src/H5Goh.c
+++ b/src/H5Goh.c
@@ -99,9 +99,9 @@ H5O_group_isa(struct H5O_t *oh)
     HDassert(oh);
 
     /* Check for any of the messages that indicate a group */
-    if((stab_exists = H5O_msg_exists_oh(oh, H5O_STAB_ID, 0)) < 0)
+    if((stab_exists = H5O_msg_exists_oh(oh, H5O_STAB_ID)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
-    if((linfo_exists = H5O_msg_exists_oh(oh, H5O_LINFO_ID, 0)) < 0)
+    if((linfo_exists = H5O_msg_exists_oh(oh, H5O_LINFO_ID)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
 
     ret_value = (stab_exists > 0 || linfo_exists > 0);
diff --git a/src/H5Gpkg.h b/src/H5Gpkg.h
index fbf1b44..d21b15a 100644
--- a/src/H5Gpkg.h
+++ b/src/H5Gpkg.h
@@ -179,7 +179,6 @@ typedef struct H5G_bt_ins_t {
 typedef struct H5G_bt_rm_t {
     /* downward */
     H5G_bt_common_t common;          /* Common info for B-tree user data (must be first) */
-    hbool_t adj_link;                   /* Whether to adjust the link count on objects */
     H5RS_str_t *grp_full_path_r;        /* Full path of group where link is removed */
 } H5G_bt_rm_t;
 
@@ -380,7 +379,7 @@ H5_DLL herr_t H5G_stab_insert(H5O_loc_t *grp_oloc, const char *name,
     H5O_link_t *obj_lnk, hid_t dxpl_id);
 H5_DLL herr_t H5G_stab_insert_real(H5F_t *f, H5O_stab_t *stab, const char *name,
     H5O_link_t *obj_lnk, hid_t dxpl_id);
-H5_DLL herr_t H5G_stab_delete(H5F_t *f, hid_t dxpl_id, const H5O_stab_t *stab, hbool_t adj_link);
+H5_DLL herr_t H5G_stab_delete(H5F_t *f, hid_t dxpl_id, const H5O_stab_t *stab);
 H5_DLL herr_t H5G_stab_iterate(H5O_loc_t *oloc, hid_t dxpl_id,
     H5_iter_order_t order, hsize_t skip, hsize_t *last_lnk, hid_t gid,
     H5G_link_iterate_t *lnk_op, void *op_data);
diff --git a/src/H5Gstab.c b/src/H5Gstab.c
index 6079427..de39441 100644
--- a/src/H5Gstab.c
+++ b/src/H5Gstab.c
@@ -268,7 +268,7 @@ H5G_stab_insert(H5O_loc_t *grp_oloc, const char *name, H5O_link_t *obj_lnk,
     HDassert(obj_lnk);
 
     /* Retrieve symbol table message */
-    if(NULL == H5O_msg_read(grp_oloc, H5O_STAB_ID, 0, &stab, dxpl_id))
+    if(NULL == H5O_msg_read(grp_oloc, H5O_STAB_ID, &stab, dxpl_id))
         HGOTO_ERROR(H5E_SYM, H5E_BADMESG, FAIL, "not a symbol table")
 
     if(H5G_stab_insert_real(grp_oloc->file, &stab, name, obj_lnk, dxpl_id) < 0)
@@ -305,13 +305,12 @@ H5G_stab_remove(H5O_loc_t *loc, hid_t dxpl_id, H5RS_str_t *grp_full_path_r,
     HDassert(name && *name);
 
     /* Read in symbol table message */
-    if(NULL == H5O_msg_read(loc, H5O_STAB_ID, 0, &stab, dxpl_id))
+    if(NULL == H5O_msg_read(loc, H5O_STAB_ID, &stab, dxpl_id))
         HGOTO_ERROR(H5E_SYM, H5E_BADMESG, FAIL, "not a symbol table")
 
     /* Initialize data to pass through B-tree */
     udata.common.name = name;
     udata.common.heap_addr = stab.heap_addr;
-    udata.adj_link = TRUE;
     udata.grp_full_path_r = grp_full_path_r;
 
     /* Remove from symbol table */
@@ -355,13 +354,12 @@ H5G_stab_remove_by_idx(H5O_loc_t *grp_oloc, hid_t dxpl_id, H5RS_str_t *grp_full_
     lnk_copied = TRUE;
 
     /* Read in symbol table message */
-    if(NULL == H5O_msg_read(grp_oloc, H5O_STAB_ID, 0, &stab, dxpl_id))
+    if(NULL == H5O_msg_read(grp_oloc, H5O_STAB_ID, &stab, dxpl_id))
         HGOTO_ERROR(H5E_SYM, H5E_BADMESG, FAIL, "not a symbol table")
 
     /* Initialize data to pass through B-tree */
     udata.common.name = obj_lnk.name;
     udata.common.heap_addr = stab.heap_addr;
-    udata.adj_link = TRUE;
     udata.grp_full_path_r = grp_full_path_r;
 
     /* Remove link from symbol table */
@@ -392,33 +390,32 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5G_stab_delete(H5F_t *f, hid_t dxpl_id, const H5O_stab_t *stab, hbool_t adj_link)
+H5G_stab_delete(H5F_t *f, hid_t dxpl_id, const H5O_stab_t *stab)
 {
     H5G_bt_rm_t	udata;		/*data to pass through B-tree	*/
     herr_t  ret_value = SUCCEED;
 
-    FUNC_ENTER_NOAPI(H5G_stab_delete, FAIL);
+    FUNC_ENTER_NOAPI(H5G_stab_delete, FAIL)
 
-    assert(f);
-    assert(stab);
-    assert(H5F_addr_defined(stab->btree_addr));
-    assert(H5F_addr_defined(stab->heap_addr));
+    HDassert(f);
+    HDassert(stab);
+    HDassert(H5F_addr_defined(stab->btree_addr));
+    HDassert(H5F_addr_defined(stab->heap_addr));
 
     /* Set up user data for B-tree deletion */
     udata.common.name = NULL;
     udata.common.heap_addr = stab->heap_addr;
-    udata.adj_link = adj_link;
 
     /* Delete entire B-tree */
     if(H5B_delete(f, dxpl_id, H5B_SNODE, stab->btree_addr, &udata) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to delete symbol table B-tree");
+        HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to delete symbol table B-tree")
 
     /* Delete local heap for names */
     if(H5HL_delete(f, dxpl_id, stab->heap_addr) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to delete symbol table heap");
+        HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to delete symbol table heap")
 
 done:
-    FUNC_LEAVE_NOAPI(ret_value);
+    FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5G_stab_delete() */
 
 
@@ -450,7 +447,7 @@ H5G_stab_iterate(H5O_loc_t *oloc, hid_t dxpl_id, H5_iter_order_t order,
     HDassert(lnk_op && lnk_op->u.old_op);
 
     /* Get the B-tree info */
-    if(NULL == H5O_msg_read(oloc, H5O_STAB_ID, 0, &stab, dxpl_id))
+    if(NULL == H5O_msg_read(oloc, H5O_STAB_ID, &stab, dxpl_id))
 	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "unable to determine local heap address")
 
     /* Check on iteration order */
@@ -539,7 +536,7 @@ H5G_stab_count(H5O_loc_t *oloc, hsize_t *num_objs, hid_t dxpl_id)
     *num_objs = 0;
 
     /* Get the B-tree info */
-    if(NULL == H5O_msg_read(oloc, H5O_STAB_ID, 0, &stab, dxpl_id))
+    if(NULL == H5O_msg_read(oloc, H5O_STAB_ID, &stab, dxpl_id))
 	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "unable to determine local heap address")
 
     /* Iterate over the group members */
@@ -627,7 +624,7 @@ H5G_stab_get_name_by_idx(H5O_loc_t *oloc, H5_iter_order_t order, hsize_t n,
     HDassert(oloc);
 
     /* Get the B-tree & local heap info */
-    if(NULL == H5O_msg_read(oloc, H5O_STAB_ID, 0, &stab, dxpl_id))
+    if(NULL == H5O_msg_read(oloc, H5O_STAB_ID, &stab, dxpl_id))
 	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "unable to determine local heap address")
 
     /* Remap index for decreasing iteration order */
@@ -761,7 +758,7 @@ H5G_stab_get_type_by_idx(H5O_loc_t *oloc, hsize_t idx, hid_t dxpl_id)
     HDassert(oloc);
 
     /* Get the B-tree & local heap info */
-    if(NULL == H5O_msg_read(oloc, H5O_STAB_ID, 0, &stab, dxpl_id))
+    if(NULL == H5O_msg_read(oloc, H5O_STAB_ID, &stab, dxpl_id))
 	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, H5G_UNKNOWN, "unable to determine local heap address")
 
     /* Set iteration information */
@@ -859,7 +856,7 @@ H5G_stab_lookup(H5O_loc_t *grp_oloc, const char *name, H5O_link_t *lnk,
     udata.lnk = lnk;
 
     /* Set up the user data for actual B-tree find operation */
-    if(NULL == H5O_msg_read(grp_oloc, H5O_STAB_ID, 0, &stab, dxpl_id))
+    if(NULL == H5O_msg_read(grp_oloc, H5O_STAB_ID, &stab, dxpl_id))
         HGOTO_ERROR(H5E_SYM, H5E_BADMESG, FAIL, "can't read message")
     bt_udata.common.name = name;
     bt_udata.common.heap_addr = stab.heap_addr;
@@ -956,7 +953,7 @@ H5G_stab_lookup_by_idx(H5O_loc_t *grp_oloc, H5_iter_order_t order, hsize_t n,
     HDassert(lnk);
 
     /* Get the B-tree & local heap info */
-    if(NULL == H5O_msg_read(grp_oloc, H5O_STAB_ID, 0, &stab, dxpl_id))
+    if(NULL == H5O_msg_read(grp_oloc, H5O_STAB_ID, &stab, dxpl_id))
 	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "unable to determine local heap address")
 
     /* Remap index for decreasing iteration order */
diff --git a/src/H5Gtest.c b/src/H5Gtest.c
index 8852adf..a2286c2 100644
--- a/src/H5Gtest.c
+++ b/src/H5Gtest.c
@@ -107,11 +107,11 @@ H5G_is_empty_test(hid_t gid)
     /* "New format" checks */
 
     /* Check if the group has any link messages */
-    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_LINK_ID, 0, H5AC_dxpl_id)) < 0)
+    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_LINK_ID, H5AC_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(msg_exists > 0) {
         /* Sanity check that new group format shouldn't have old messages */
-        if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, 0, H5AC_dxpl_id)) < 0)
+        if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, H5AC_dxpl_id)) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
         if(msg_exists > 0)
             HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, FAIL, "both symbol table and link messages found")
@@ -120,19 +120,19 @@ H5G_is_empty_test(hid_t gid)
     } /* end if */
 
     /* Check for a link info message */
-    if((linfo_exists = H5O_msg_exists(&(grp->oloc), H5O_LINFO_ID, 0, H5AC_dxpl_id)) < 0)
+    if((linfo_exists = H5O_msg_exists(&(grp->oloc), H5O_LINFO_ID, H5AC_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(linfo_exists > 0) {
         H5O_linfo_t linfo;		/* Link info message */
 
         /* Sanity check that new group format shouldn't have old messages */
-        if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, 0, H5AC_dxpl_id)) < 0)
+        if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, H5AC_dxpl_id)) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
         if(msg_exists > 0)
             HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, FAIL, "both symbol table and link info messages found")
 
         /* Get the link info */
-        if(NULL == H5O_msg_read(&(grp->oloc), H5O_LINFO_ID, 0, &linfo, H5AC_dxpl_id))
+        if(NULL == H5O_msg_read(&(grp->oloc), H5O_LINFO_ID, &linfo, H5AC_dxpl_id))
             HGOTO_ERROR(H5E_SYM, H5E_BADMESG, FAIL, "can't get link info")
 
         /* Check for 'dense' link storage file addresses being defined */
@@ -151,7 +151,7 @@ H5G_is_empty_test(hid_t gid)
     /* "Old format" checks */
 
     /* Check if the group has a symbol table message */
-    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, 0, H5AC_dxpl_id)) < 0)
+    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, H5AC_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(msg_exists > 0) {
         H5O_stab_t stab;        /* Info about local heap & B-tree */
@@ -160,13 +160,13 @@ H5G_is_empty_test(hid_t gid)
         /* Sanity check that old group format shouldn't have new messages */
         if(linfo_exists > 0)
             HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, FAIL, "both symbol table and link info messages found")
-        if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_GINFO_ID, 0, H5AC_dxpl_id)) < 0)
+        if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_GINFO_ID, H5AC_dxpl_id)) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
         if(msg_exists > 0)
             HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, FAIL, "both symbol table and group info messages found")
 
         /* Get the B-tree & local heap info */
-        if(NULL == H5O_msg_read(&(grp->oloc), H5O_STAB_ID, 0, &stab, H5AC_dxpl_id))
+        if(NULL == H5O_msg_read(&(grp->oloc), H5O_STAB_ID, &stab, H5AC_dxpl_id))
             HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "unable to read symbol table message")
 
         /* Get the count of links in the group */
@@ -216,13 +216,13 @@ H5G_has_links_test(hid_t gid, unsigned *nmsgs)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group")
 
     /* Check if the group has any link messages */
-    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_LINK_ID, 0, H5AC_dxpl_id)) < 0)
+    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_LINK_ID, H5AC_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(msg_exists == 0)
         HGOTO_DONE(FALSE)
 
     /* Check if the group has a symbol table message */
-    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, 0, H5AC_dxpl_id)) < 0)
+    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, H5AC_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(msg_exists > 0)
 	HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, FAIL, "both symbol table and link messages found")
@@ -274,13 +274,13 @@ H5G_has_stab_test(hid_t gid)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group")
 
     /* Check if the group has a symbol table message */
-    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, 0, H5AC_dxpl_id)) < 0)
+    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, H5AC_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(msg_exists == 0)
         HGOTO_DONE(FALSE)
 
     /* Check if the group has any link messages */
-    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_LINK_ID, 0, H5AC_dxpl_id)) < 0)
+    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_LINK_ID, H5AC_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(msg_exists > 0)
 	HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, FAIL, "both symbol table and link messages found")
@@ -324,25 +324,25 @@ H5G_is_new_dense_test(hid_t gid)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group")
 
     /* Check if the group has a symbol table message */
-    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, 0, H5AC_dxpl_id)) < 0)
+    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_STAB_ID, H5AC_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(msg_exists > 0)
         HGOTO_DONE(FALSE)
 
     /* Check if the group has any link messages */
-    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_LINK_ID, 0, H5AC_dxpl_id)) < 0)
+    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_LINK_ID, H5AC_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(msg_exists > 0)
         HGOTO_DONE(FALSE)
 
     /* Check if the group has link info message */
-    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_LINFO_ID, 0, H5AC_dxpl_id)) < 0)
+    if((msg_exists = H5O_msg_exists(&(grp->oloc), H5O_LINFO_ID, H5AC_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read object header")
     if(msg_exists > 0) {
         H5O_linfo_t linfo;		/* Link info message */
 
         /* Get the link info */
-        if(NULL == H5O_msg_read(&(grp->oloc), H5O_LINFO_ID, 0, &linfo, H5AC_dxpl_id))
+        if(NULL == H5O_msg_read(&(grp->oloc), H5O_LINFO_ID, &linfo, H5AC_dxpl_id))
             HGOTO_ERROR(H5E_SYM, H5E_BADMESG, FAIL, "can't get link info")
 
         /* Check for 'dense' link storage file addresses being defined */
@@ -392,7 +392,7 @@ H5G_new_dense_info_test(hid_t gid, hsize_t *name_count, hsize_t *corder_count)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group")
 
     /* Get the link info */
-    if(NULL == H5O_msg_read(&(grp->oloc), H5O_LINFO_ID, 0, &linfo, H5AC_dxpl_id))
+    if(NULL == H5O_msg_read(&(grp->oloc), H5O_LINFO_ID, &linfo, H5AC_dxpl_id))
         HGOTO_ERROR(H5E_SYM, H5E_BADMESG, FAIL, "can't get link info")
 
     /* Check for 'dense' link storage file addresses being defined */
@@ -452,7 +452,7 @@ H5G_lheap_size_test(hid_t gid, size_t *lheap_size)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group")
 
     /* Make certain the group has a symbol table message */
-    if(NULL == H5O_msg_read(&(grp->oloc), H5O_STAB_ID, 0, &stab, H5AC_dxpl_id))
+    if(NULL == H5O_msg_read(&(grp->oloc), H5O_STAB_ID, &stab, H5AC_dxpl_id))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to read symbol table message")
 
     /* Check the size of the local heap for the group */
diff --git a/src/H5Gtraverse.c b/src/H5Gtraverse.c
index ad39402..80e1a6f 100644
--- a/src/H5Gtraverse.c
+++ b/src/H5Gtraverse.c
@@ -700,7 +700,7 @@ H5G_traverse_real(const H5G_loc_t *_loc, const char *name, unsigned target,
 
                 /* Get the group info for parent group */
                 /* (OK if not found) */
-                if(NULL == H5O_msg_read(grp_loc.oloc, H5O_GINFO_ID, 0, &par_ginfo, dxpl_id)) {
+                if(NULL == H5O_msg_read(grp_loc.oloc, H5O_GINFO_ID, &par_ginfo, dxpl_id)) {
                     /* Clear error stack from not finding the group info message */
                     H5E_clear_stack(NULL);
 
@@ -712,7 +712,7 @@ H5G_traverse_real(const H5G_loc_t *_loc, const char *name, unsigned target,
 
                 /* Get the link info for parent group */
                 /* (OK if not found) */
-                if(NULL == H5O_msg_read(grp_loc.oloc, H5O_LINFO_ID, 0, &par_linfo, dxpl_id)) {
+                if(NULL == H5O_msg_read(grp_loc.oloc, H5O_LINFO_ID, &par_linfo, dxpl_id)) {
                     /* Clear error stack from not finding the link info message */
                     H5E_clear_stack(NULL);
 
diff --git a/src/H5O.c b/src/H5O.c
index be16c6a..74edeca 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -1108,15 +1108,18 @@ H5O_touch_oh(H5F_t *f,
 
         /* Create a new message, if necessary */
         if(idx == oh->nmesgs) {
-            size_t	size;           /* New modification time message size */
+            unsigned mesg_flags = 0;        /* Flags for message in object header */
 
             /* If we would have to create a new message, but we aren't 'forcing' it, get out now */
             if(!force)
                 HGOTO_DONE(SUCCEED);        /*nothing to do*/
 
-            size = (H5O_MSG_MTIME_NEW->raw_size)(f, FALSE, &now);
-            if((idx = H5O_alloc(f, dxpl_id, oh, H5O_MSG_MTIME_NEW, size, oh_flags_ptr)) == UFAIL)
+            /* Allocate space for the modification time message */
+            if((idx = H5O_msg_alloc(f, dxpl_id, oh, H5O_MSG_MTIME_NEW, &mesg_flags, &now, oh_flags_ptr)) == UFAIL)
                 HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "unable to allocate space for modification time message")
+
+            /* Set the message's flags if appropriate */
+            oh->mesg[idx].flags = mesg_flags;
         } /* end if */
 
         /* Allocate 'native' space, if necessary */
@@ -1225,20 +1228,26 @@ H5O_bogus_oh(H5F_t *f, hid_t dxpl_id, H5O_t *oh, hbool_t * oh_flags_ptr)
 
     /* Create a new message */
     if(idx == oh->nmesgs) {
-        size_t	size = (H5O_MSG_BOGUS->raw_size)(f, NULL);
-
-	if((idx = H5O_alloc(f, dxpl_id, oh, H5O_MSG_BOGUS, size, oh_flags_ptr)) < 0)
-	    HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "unable to allocate space for 'bogus' message")
+        H5O_bogus_t *bogus;             /* Pointer to the bogus information */
+        unsigned mesg_flags = 0;        /* Flags for message in object header */
 
         /* Allocate the native message in memory */
-	if(NULL == (oh->mesg[idx].native = H5MM_malloc(sizeof(H5O_bogus_t))))
+	if(NULL == (bogus = H5MM_malloc(sizeof(H5O_bogus_t))))
 	    HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "memory allocation failed for 'bogus' message")
 
-        /* Update the native part */
-        ((H5O_bogus_t *)(oh->mesg[idx].native))->u = H5O_BOGUS_VALUE;
+        /* Update the native value */
+        bogus->u = H5O_BOGUS_VALUE;
+
+        /* Allocate space in the object header for bogus message */
+	if((idx = H5O_msg_alloc(f, dxpl_id, oh, H5O_MSG_BOGUS, &mesg_flags, bogus, oh_flags_ptr)) < 0)
+	    HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "unable to allocate space for 'bogus' message")
+
+        /* Point to "bogus" information (take it over) */
+	oh->mesg[idx].native = bogus;
 
         /* Mark the message and object header as dirty */
 	*oh_flags_ptr = TRUE;
+        oh->mesg[idx].flags = mesg_flags;
         oh->mesg[idx].dirty = TRUE;
         oh->dirty = TRUE;
     } /* end if */
@@ -1375,7 +1384,7 @@ H5O_delete_oh(H5F_t *f, hid_t dxpl_id, H5O_t *oh)
      */
     for(u = 0, curr_msg = &oh->mesg[0]; u < oh->nmesgs; u++, curr_msg++) {
         /* Free any space referred to in the file from this message */
-        if(H5O_delete_mesg(f, dxpl_id, curr_msg, TRUE) < 0)
+        if(H5O_delete_mesg(f, dxpl_id, curr_msg) < 0)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTDELETE, FAIL, "unable to delete file space for object header message")
     } /* end for */
 
@@ -1812,9 +1821,9 @@ H5O_get_info(H5O_loc_t *oloc, H5O_info_t *oinfo, hid_t dxpl_id)
         oinfo->btime = 0;
 
         /* Might be information for modification time */
-        if(NULL == H5O_msg_read_real(oloc->file, oh, H5O_MTIME_ID, 0, &oinfo->ctime, dxpl_id)) {
+        if(NULL == H5O_msg_read_real(oloc->file, dxpl_id, oh, H5O_MTIME_ID, &oinfo->ctime)) {
             H5E_clear_stack(NULL);
-            if(NULL == H5O_msg_read_real(oloc->file, oh, H5O_MTIME_NEW_ID, 0, &oinfo->ctime, dxpl_id)) {
+            if(NULL == H5O_msg_read_real(oloc->file, dxpl_id, oh, H5O_MTIME_NEW_ID, &oinfo->ctime)) {
                 H5E_clear_stack(NULL);
                 oinfo->ctime = 0;
             } /* end if */
diff --git a/src/H5Oalloc.c b/src/H5Oalloc.c
index 9c29783..eecb405 100644
--- a/src/H5Oalloc.c
+++ b/src/H5Oalloc.c
@@ -839,9 +839,10 @@ done:
  */
 unsigned
 H5O_alloc(H5F_t *f, hid_t dxpl_id, H5O_t *oh, const H5O_msg_class_t *type,
-    size_t size, unsigned * oh_flags_ptr)
+    const void *mesg, unsigned * oh_flags_ptr)
 {
-    size_t      aligned_size = H5O_ALIGN_OH(oh, size);
+    size_t      raw_size;       /* Raw size of message */
+    size_t      aligned_size;   /* Size of message including alignment */
     unsigned    idx;            /* Index of message which fits allocation */
     unsigned    ret_value;      /* Return value */
 
@@ -850,8 +851,14 @@ H5O_alloc(H5F_t *f, hid_t dxpl_id, H5O_t *oh, const H5O_msg_class_t *type,
     /* check args */
     HDassert(oh);
     HDassert(type);
+    HDassert(mesg);
     HDassert(oh_flags_ptr);
 
+    /* Compute the size needed to store the message in the object header */
+    if((raw_size = (type->raw_size)(f, FALSE, mesg)) >= H5O_MESG_MAX_SIZE)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, UFAIL, "object header message is too large")
+    aligned_size = H5O_ALIGN_OH(oh, raw_size);
+
     /* look for a null message which is large enough */
     for(idx = 0; idx < oh->nmesgs; idx++)
         if(H5O_NULL_ID == oh->mesg[idx].type->id && oh->mesg[idx].raw_size >= aligned_size)
@@ -872,7 +879,7 @@ H5O_alloc(H5F_t *f, hid_t dxpl_id, H5O_t *oh, const H5O_msg_class_t *type,
 
             HDassert(H5F_addr_defined(oh->chunk[chunkno].addr));
 
-            tri_result = H5O_alloc_extend_chunk(f, oh, chunkno, size, &idx);
+            tri_result = H5O_alloc_extend_chunk(f, oh, chunkno, raw_size, &idx);
             if(tri_result == TRUE)
 		break;
             else if(tri_result == FALSE)
@@ -885,7 +892,7 @@ H5O_alloc(H5F_t *f, hid_t dxpl_id, H5O_t *oh, const H5O_msg_class_t *type,
          *      create a new one.
          */
         if(idx == UFAIL)
-            if((idx = H5O_alloc_new_chunk(f, dxpl_id, oh, size)) == UFAIL)
+            if((idx = H5O_alloc_new_chunk(f, dxpl_id, oh, raw_size)) == UFAIL)
                 HGOTO_ERROR(H5E_OHDR, H5E_NOSPACE, UFAIL, "unable to create a new object header data chunk")
     } /* end if */
 
@@ -920,7 +927,7 @@ done:
  */
 herr_t
 H5O_release_mesg(H5F_t *f, hid_t dxpl_id, H5O_t *oh, H5O_mesg_t *mesg,
-    hbool_t delete_mesg, hbool_t adj_link)
+    hbool_t adj_link)
 {
     herr_t ret_value = SUCCEED; 	                /* Return value */
 
@@ -932,9 +939,9 @@ H5O_release_mesg(H5F_t *f, hid_t dxpl_id, H5O_t *oh, H5O_mesg_t *mesg,
     HDassert(mesg);
 
     /* Check if we should operate on the message */
-    if(delete_mesg) {
+    if(adj_link) {
         /* Free any space referred to in the file from this message */
-        if(H5O_delete_mesg(f, dxpl_id, mesg, adj_link) < 0)
+        if(H5O_delete_mesg(f, dxpl_id, mesg) < 0)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTDELETE, FAIL, "unable to delete file space for object header message")
     } /* end if */
 
@@ -1368,7 +1375,7 @@ H5O_remove_empty_chunks(H5F_t *f, H5O_t *oh, hid_t dxpl_id)
                 deleted_chunkno = null_msg->chunkno;
 
                 /* Convert continuation message into a null message */
-                if(H5O_release_mesg(f, dxpl_id, oh, cont_msg, TRUE, TRUE) < 0)
+                if(H5O_release_mesg(f, dxpl_id, oh, cont_msg, TRUE) < 0)
                     HGOTO_ERROR(H5E_OHDR, H5E_CANTDELETE, FAIL, "unable to convert into null message")
 
                 /*
diff --git a/src/H5Oattr.c b/src/H5Oattr.c
index 35c52ef..ad617aa 100644
--- a/src/H5Oattr.c
+++ b/src/H5Oattr.c
@@ -588,7 +588,7 @@ H5O_attr_free(void *mesg)
  *-------------------------------------------------------------------------
  */
 herr_t
-H5O_attr_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link)
+H5O_attr_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg)
 {
     const H5A_t            *attr = (const H5A_t *) _mesg;
     herr_t ret_value = SUCCEED;   /* Return value */
@@ -600,11 +600,11 @@ H5O_attr_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link)
     HDassert(attr);
 
     /* Decrement reference count on datatype in file */
-    if((H5O_MSG_DTYPE->del)(f, dxpl_id, attr->dt, adj_link) < 0)
+    if((H5O_MSG_DTYPE->del)(f, dxpl_id, attr->dt) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_LINKCOUNT, FAIL, "unable to adjust datatype link count")
 
     /* Decrement reference count on dataspace in file */
-    if((H5O_MSG_SDSPACE->del)(f, dxpl_id, attr->ds, adj_link) < 0)
+    if((H5O_MSG_SDSPACE->del)(f, dxpl_id, attr->ds) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_LINKCOUNT, FAIL, "unable to adjust dataspace link count")
 
 done:
diff --git a/src/H5Oattribute.c b/src/H5Oattribute.c
index 5e2c4df..feb2da0 100644
--- a/src/H5Oattribute.c
+++ b/src/H5Oattribute.c
@@ -176,7 +176,7 @@ H5O_attr_to_dense_cb(H5O_t *oh, H5O_mesg_t *mesg/*in,out*/,
 
     /* Convert message into a null message in the header */
     /* (don't delete attribute's space in the file though) */
-    if(H5O_release_mesg(udata->f, udata->dxpl_id, oh, mesg, FALSE, FALSE) < 0)
+    if(H5O_release_mesg(udata->f, udata->dxpl_id, oh, mesg, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTDELETE, H5_ITER_ERROR, "unable to convert into null message")
 
     /* Indicate that the object header was modified */
@@ -294,7 +294,7 @@ H5O_attr_create(const H5O_loc_t *loc, hid_t dxpl_id, H5A_t *attr)
          *      *ick* -QAK, 2007/01/08
          */
         if(attr_rc > 1) {
-            if(H5O_attr_delete(loc->file, dxpl_id, attr, TRUE) < 0)
+            if(H5O_attr_delete(loc->file, dxpl_id, attr) < 0)
                 HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
         } /* end if */
     } /* end if */
@@ -815,7 +815,7 @@ H5O_attr_rename_mod_cb(H5O_t *oh, H5O_mesg_t *mesg/*in,out*/,
                 /* (doesn't decrement the link count on shared components becuase
                  *      the "native" pointer has been reset)
                  */
-                if(H5O_release_mesg(udata->f, udata->dxpl_id, oh, mesg, FALSE, FALSE) < 0)
+                if(H5O_release_mesg(udata->f, udata->dxpl_id, oh, mesg, FALSE) < 0)
                     HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, H5_ITER_ERROR, "unable to release previous attribute")
 
                 /* Increment attribute count */
@@ -1054,7 +1054,7 @@ H5O_attr_remove_cb(H5O_t *oh, H5O_mesg_t *mesg/*in,out*/,
             oh->nattrs--;
 
         /* Convert message into a null message (i.e. delete it) */
-        if(H5O_release_mesg(udata->f, udata->dxpl_id, oh, mesg, TRUE, TRUE) < 0)
+        if(H5O_release_mesg(udata->f, udata->dxpl_id, oh, mesg, TRUE) < 0)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTDELETE, H5_ITER_ERROR, "unable to convert into null message")
 
         /* Indicate that the object header was modified */
diff --git a/src/H5Ocont.c b/src/H5Ocont.c
index f378611..8e489a8 100644
--- a/src/H5Ocont.c
+++ b/src/H5Ocont.c
@@ -40,7 +40,7 @@ static void *H5O_cont_decode(H5F_t *f, hid_t dxpl_id, unsigned mesg_flags, const
 static herr_t H5O_cont_encode(H5F_t *f, hbool_t disable_shared, uint8_t *p, const void *_mesg);
 static size_t H5O_cont_size(const H5F_t *f, hbool_t disable_shared, const void *_mesg);
 static herr_t H5O_cont_free(void *mesg);
-static herr_t H5O_cont_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link);
+static herr_t H5O_cont_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg);
 static herr_t H5O_cont_debug(H5F_t *f, hid_t dxpl_id, const void *_mesg, FILE * stream,
 			     int indent, int fwidth);
 
@@ -222,7 +222,7 @@ H5O_cont_free(void *mesg)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5O_cont_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t UNUSED adj_link)
+H5O_cont_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg)
 {
     const H5O_cont_t     *mesg = (const H5O_cont_t *) _mesg;
     herr_t ret_value = SUCCEED;   /* Return value */
diff --git a/src/H5Ocopy.c b/src/H5Ocopy.c
index b50ecd9..1592278 100644
--- a/src/H5Ocopy.c
+++ b/src/H5Ocopy.c
@@ -454,12 +454,9 @@ H5O_copy_header_real(const H5O_loc_t *oloc_src, H5O_loc_t *oloc_dst /*out */,
         mesg_src = &(oh_src->mesg[mesgno + null_msgs]);
         mesg_dst = &(oh_dst->mesg[mesgno]);
 
-        /* Initialize on destination message */
-        mesg_dst->chunkno = 0;
-        mesg_dst->dirty = FALSE;
+        /* Initialize non-zero components of destination message */
+        mesg_dst->crt_idx = mesg_src->crt_idx;
         mesg_dst->flags = mesg_src->flags;
-        mesg_dst->native = NULL;
-        mesg_dst->raw = NULL;
         mesg_dst->raw_size = mesg_src->raw_size;
         mesg_dst->type = mesg_src->type;
 
@@ -481,6 +478,8 @@ H5O_copy_header_real(const H5O_loc_t *oloc_src, H5O_loc_t *oloc_dst /*out */,
 
         /* copy this message into destination file */
         if(copy_type->copy_file) {
+            hbool_t recompute_size = FALSE;     /* Whether to recompute the destination message's size */
+
             /* Decode the message if necessary. */
             H5O_LOAD_NATIVE(oloc_src->file, dxpl_id, mesg_src, FAIL)
 
@@ -501,8 +500,7 @@ H5O_copy_header_real(const H5O_loc_t *oloc_src, H5O_loc_t *oloc_dst /*out */,
                 /* Recompute shared message size (mesg_dst->native is really
                  * shared)
                  */
-                mesg_dst->raw_size = H5O_ALIGN_OH(oh_dst,
-                        H5O_msg_raw_size(oloc_dst->file, mesg_dst->type->id, FALSE, mesg_dst->native));
+                recompute_size = TRUE;
             } /* end if */
             else if(shared == FALSE && (mesg_dst->flags & H5O_MSG_FLAG_SHARED)) {
                 /* Unset shared flag */
@@ -511,9 +509,11 @@ H5O_copy_header_real(const H5O_loc_t *oloc_src, H5O_loc_t *oloc_dst /*out */,
                 /* Recompute native message size (msg_dest->native is no longer
                  * shared)
                  */
+                recompute_size = TRUE;
+            } /* end else */
+            if(recompute_size)
                 mesg_dst->raw_size = H5O_ALIGN_OH(oh_dst,
                         H5O_msg_raw_size(oloc_dst->file, mesg_dst->type->id, FALSE, mesg_dst->native));
-            } /* end else */
 
             /* Mark the message in the destination as dirty, so it'll get encoded when the object header is flushed */
             mesg_dst->dirty = TRUE;
@@ -585,7 +585,7 @@ H5O_copy_header_real(const H5O_loc_t *oloc_src, H5O_loc_t *oloc_dst /*out */,
         mesg_src = &(oh_src->mesg[mesgno + null_msgs]);
         mesg_dst = &(oh_dst->mesg[mesgno]);
 
-        if(! mesg_dst->dirty) {
+        if(!mesg_dst->dirty) {
             /* Copy the message header plus the message's raw data. */
             HDmemcpy(current_pos, mesg_src->raw - msghdr_size,
                     msghdr_size + mesg_src->raw_size);
diff --git a/src/H5Olayout.c b/src/H5Olayout.c
index a542a7d..3736b8b 100644
--- a/src/H5Olayout.c
+++ b/src/H5Olayout.c
@@ -38,8 +38,7 @@ static void *H5O_layout_copy(const void *_mesg, void *_dest);
 static size_t H5O_layout_size(const H5F_t *f, hbool_t disable_shared, const void *_mesg);
 static herr_t H5O_layout_reset(void *_mesg);
 static herr_t H5O_layout_free(void *_mesg);
-static herr_t H5O_layout_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg,
-    hbool_t adj_link);
+static herr_t H5O_layout_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg);
 static void *H5O_layout_copy_file(H5F_t *file_src, void *mesg_src,
     H5F_t *file_dst, hid_t dxpl_id, H5O_copy_t *cpy_info, void *udata);
 static herr_t H5O_layout_debug(H5F_t *f, hid_t dxpl_id, const void *_mesg, FILE * stream,
@@ -554,8 +553,7 @@ H5O_layout_free (void *_mesg)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5O_layout_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg,
-    hbool_t UNUSED adj_link)
+H5O_layout_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg)
 {
     const H5O_layout_t *mesg = (const H5O_layout_t *) _mesg;
     herr_t ret_value = SUCCEED;   /* Return value */
diff --git a/src/H5Olinfo.c b/src/H5Olinfo.c
index b5c4041..abbb411 100644
--- a/src/H5Olinfo.c
+++ b/src/H5Olinfo.c
@@ -39,7 +39,7 @@ static herr_t H5O_linfo_encode(H5F_t *f, hbool_t disable_shared, uint8_t *p, con
 static void *H5O_linfo_copy(const void *_mesg, void *_dest);
 static size_t H5O_linfo_size(const H5F_t *f, hbool_t disable_shared, const void *_mesg);
 static herr_t H5O_linfo_free(void *_mesg);
-static herr_t H5O_linfo_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link);
+static herr_t H5O_linfo_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg);
 static void *H5O_linfo_copy_file(H5F_t *file_src, 
     void *native_src, H5F_t *file_dst, hid_t dxpl_id, H5O_copy_t *cpy_info,
     void *udata);
@@ -341,7 +341,7 @@ H5O_linfo_free(void *mesg)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5O_linfo_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link)
+H5O_linfo_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg)
 {
     const H5O_linfo_t *linfo = (const H5O_linfo_t *)_mesg;
     herr_t ret_value = SUCCEED;   /* Return value */
@@ -354,7 +354,7 @@ H5O_linfo_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link)
 
     /* If the group is using "dense" link storage, delete it */
     if(H5F_addr_defined(linfo->link_fheap_addr))
-        if(H5G_dense_delete(f, dxpl_id, (H5O_linfo_t *)linfo, adj_link) < 0)   /* Casting away const OK - QAK */
+        if(H5G_dense_delete(f, dxpl_id, (H5O_linfo_t *)linfo, TRUE) < 0)   /* Casting away const OK - QAK */
             HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free dense link storage")
 
 done:
diff --git a/src/H5Olink.c b/src/H5Olink.c
index 47ebfdb..628ce56 100644
--- a/src/H5Olink.c
+++ b/src/H5Olink.c
@@ -43,7 +43,6 @@ static void *H5O_link_copy(const void *_mesg, void *_dest);
 static size_t H5O_link_size(const H5F_t *f, hbool_t disable_shared, const void *_mesg);
 static herr_t H5O_link_reset(void *_mesg);
 static herr_t H5O_link_free(void *_mesg);
-/* static herr_t H5O_link_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link); */
 static herr_t H5O_link_pre_copy_file(H5F_t *file_src, const void *mesg_src,
     hbool_t *deleted, const H5O_copy_t *cpy_info, void *udata);
 static void *H5O_link_copy_file(H5F_t *file_src, void *native_src,
@@ -494,7 +493,7 @@ H5O_link_free(void *_mesg)
  *-------------------------------------------------------------------------
  */
 herr_t
-H5O_link_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link)
+H5O_link_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg)
 {
     const H5O_link_t *lnk = (const H5O_link_t *)_mesg;
     herr_t ret_value = SUCCEED;   /* Return value */
@@ -506,47 +505,45 @@ H5O_link_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link)
     HDassert(lnk);
 
     /* Check for adjusting the link count when the link is removed */
-    if(adj_link) {
-        /* Adjust the reference count of the object when a hard link is removed */
-        if(lnk->type == H5L_TYPE_HARD) {
-            H5O_loc_t oloc;
-
-            /* Construct object location for object, in order to decrement it's ref count */
-            H5O_loc_reset(&oloc);
-            oloc.file = f;
-            HDassert(H5F_addr_defined(lnk->u.hard.addr));
-            oloc.addr = lnk->u.hard.addr;
-
-            /* Decrement the ref count for the object */
-            if(H5O_link(&oloc, -1, dxpl_id) < 0)
-                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to decrement object link count")
-        } /* end if */
-        /* Perform the "delete" callback when a user-defined link is removed */
-        else if(lnk->type >= H5L_TYPE_UD_MIN) {
-            const H5L_class_t   *link_class;         /* User-defined link class */
-
-            /* Get the link class for this type of link. */
-            if(NULL == (link_class = H5L_find_class(lnk->type)))
-                HGOTO_ERROR(H5E_LINK, H5E_NOTREGISTERED, FAIL, "link class not registered")
-
-            /* Check for delete callback */
-            if(link_class->del_func) {
-                hid_t file_id;           /* ID for the file the link is located in (passed to user callback) */
-
-                /* Get a file ID for the file the link is in */
-                if((file_id = H5F_get_id(f)) < 0)
-                    HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to get file ID")
-
-                /* Call user-defined link's 'delete' callback */
-                if((link_class->del_func)(lnk->name, file_id, lnk->u.ud.udata, lnk->u.ud.size) < 0) {
-                    H5I_dec_ref(file_id);
-                    HGOTO_ERROR(H5E_OHDR, H5E_CALLBACK, FAIL, "link deletion callback returned failure")
-                } /* end if */
+    /* Adjust the reference count of the object when a hard link is removed */
+    if(lnk->type == H5L_TYPE_HARD) {
+        H5O_loc_t oloc;
+
+        /* Construct object location for object, in order to decrement it's ref count */
+        H5O_loc_reset(&oloc);
+        oloc.file = f;
+        HDassert(H5F_addr_defined(lnk->u.hard.addr));
+        oloc.addr = lnk->u.hard.addr;
+
+        /* Decrement the ref count for the object */
+        if(H5O_link(&oloc, -1, dxpl_id) < 0)
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to decrement object link count")
+    } /* end if */
+    /* Perform the "delete" callback when a user-defined link is removed */
+    else if(lnk->type >= H5L_TYPE_UD_MIN) {
+        const H5L_class_t   *link_class;         /* User-defined link class */
 
-                /* Release the file ID */
-                if(H5I_dec_ref(file_id) < 0)
-                    HGOTO_ERROR(H5E_OHDR, H5E_CANTCLOSEFILE, FAIL, "can't close file")
+        /* Get the link class for this type of link. */
+        if(NULL == (link_class = H5L_find_class(lnk->type)))
+            HGOTO_ERROR(H5E_LINK, H5E_NOTREGISTERED, FAIL, "link class not registered")
+
+        /* Check for delete callback */
+        if(link_class->del_func) {
+            hid_t file_id;           /* ID for the file the link is located in (passed to user callback) */
+
+            /* Get a file ID for the file the link is in */
+            if((file_id = H5F_get_id(f)) < 0)
+                HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to get file ID")
+
+            /* Call user-defined link's 'delete' callback */
+            if((link_class->del_func)(lnk->name, file_id, lnk->u.ud.udata, lnk->u.ud.size) < 0) {
+                H5I_dec_ref(file_id);
+                HGOTO_ERROR(H5E_OHDR, H5E_CALLBACK, FAIL, "link deletion callback returned failure")
             } /* end if */
+
+            /* Release the file ID */
+            if(H5I_dec_ref(file_id) < 0)
+                HGOTO_ERROR(H5E_OHDR, H5E_CANTCLOSEFILE, FAIL, "can't close file")
         } /* end if */
     } /* end if */
 
diff --git a/src/H5Omessage.c b/src/H5Omessage.c
index 99cbed6..d598819 100644
--- a/src/H5Omessage.c
+++ b/src/H5Omessage.c
@@ -71,18 +71,16 @@ typedef struct {
 /* Local Prototypes */
 /********************/
 
-static herr_t H5O_msg_write_real(H5F_t *f, H5O_t *oh, const H5O_msg_class_t *type,
-    unsigned overwrite, unsigned mesg_flags, unsigned update_flags,
-    void *mesg, hid_t dxpl_id, unsigned *oh_flags_ptr);
+static herr_t H5O_msg_write_real(H5F_t *f, hid_t dxpl_id, H5O_t *oh,
+    const H5O_msg_class_t *type, unsigned mesg_flags, unsigned update_flags,
+    void *mesg, unsigned *oh_flags_ptr);
 static herr_t H5O_msg_reset_real(const H5O_msg_class_t *type, void *native);
 static herr_t H5O_msg_remove_real(const H5O_loc_t *loc, const H5O_msg_class_t *type,
     int sequence, H5O_operator_t op, void *op_data, hbool_t adj_link, hid_t dxpl_id);
 static herr_t H5O_msg_remove_cb(H5O_t *oh, H5O_mesg_t *mesg/*in,out*/, 
     unsigned sequence, unsigned *oh_flags_ptr, void *_udata/*in,out*/);
-static unsigned H5O_new_mesg(H5F_t *f, H5O_t *oh, unsigned *flags,
-    const H5O_msg_class_t *type, void *mesg, hid_t dxpl_id, unsigned *oh_flags_ptr);
 static herr_t H5O_copy_mesg(H5F_t *f, hid_t dxpl_id, H5O_t *oh, unsigned idx,
-    const H5O_msg_class_t *type, const void *mesg, unsigned flags,
+    const H5O_msg_class_t *type, const void *mesg, unsigned mesg_flags,
     unsigned update_flags, unsigned *oh_flags_ptr);
 
 
@@ -232,8 +230,8 @@ H5O_msg_append_real(H5F_t *f, hid_t dxpl_id, H5O_t *oh, const H5O_msg_class_t *t
     HDassert(mesg);
     HDassert(oh_flags_ptr);
 
-    /* Create a new message */
-    if((idx = H5O_new_mesg(f, oh, &mesg_flags, type, mesg, dxpl_id, oh_flags_ptr)) == UFAIL)
+    /* Allocate space for a new message */
+    if((idx = H5O_msg_alloc(f, dxpl_id, oh, type, &mesg_flags, mesg, oh_flags_ptr)) == UFAIL)
         HGOTO_ERROR(H5E_OHDR, H5E_NOSPACE, FAIL, "unable to create new message")
 
     /* Copy the information for the message */
@@ -253,11 +251,6 @@ done:
  *
  * Purpose:	Modifies an existing message or creates a new message.
  *
- *		The OVERWRITE argument is a sequence number of a
- *		message to overwrite (usually zero).
- *		If the message to overwrite doesn't exist then this routine
- *              fails.
- *
  *              The UPDATE_FLAGS argument are flags that allow the caller
  *              to skip updating the modification time or reseting the message
  *              data.  This is useful when several calls to H5O_msg_write will be
@@ -274,8 +267,8 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5O_msg_write(H5O_loc_t *loc, unsigned type_id, unsigned overwrite,
-   unsigned mesg_flags, unsigned update_flags, void *mesg, hid_t dxpl_id)
+H5O_msg_write(H5O_loc_t *loc, unsigned type_id, unsigned mesg_flags,
+    unsigned update_flags, void *mesg, hid_t dxpl_id)
 {
     H5O_t *oh = NULL;                   /* Object header to use */
     unsigned oh_flags = H5AC__NO_FLAGS_SET;     /* Flags to unprotect object header */
@@ -304,7 +297,7 @@ H5O_msg_write(H5O_loc_t *loc, unsigned type_id, unsigned overwrite,
 	HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, FAIL, "unable to load object header")
 
     /* Call the "real" modify routine */
-    if(H5O_msg_write_real(loc->file, oh, type, overwrite, mesg_flags, update_flags, mesg, dxpl_id, &oh_flags) < 0)
+    if(H5O_msg_write_real(loc->file, dxpl_id, oh, type, mesg_flags, update_flags, mesg, &oh_flags) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_WRITEERROR, FAIL, "unable to write object header message")
 
 done:
@@ -320,11 +313,6 @@ done:
  *
  * Purpose:	Modifies an existing message or creates a new message.
  *
- *		The OVERWRITE argument is a sequence number of a
- *		message to overwrite (usually zero).
- *		If the message to overwrite doesn't exist then this routine
- *              fails.
- *
  *              The UPDATE_FLAGS argument are flags that allow the caller
  *              to skip updating the modification time or reseting the message
  *              data.  This is useful when several calls to H5O_msg_write will be
@@ -341,12 +329,10 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5O_msg_write_real(H5F_t *f, H5O_t *oh, const H5O_msg_class_t *type,
-    unsigned overwrite, unsigned mesg_flags, unsigned update_flags,
-    void *mesg, hid_t dxpl_id, unsigned *oh_flags_ptr)
+H5O_msg_write_real(H5F_t *f, hid_t dxpl_id, H5O_t *oh, const H5O_msg_class_t *type,
+    unsigned mesg_flags, unsigned update_flags, void *mesg, unsigned *oh_flags_ptr)
 {
     H5O_mesg_t         *idx_msg;        /* Pointer to message to modify */
-    int	        	sequence;       /* Sequence # of message type to modify */
     unsigned		idx;            /* Index of message to modify */
     herr_t	        ret_value = SUCCEED;    /* Return value */
 
@@ -361,16 +347,11 @@ H5O_msg_write_real(H5F_t *f, H5O_t *oh, const H5O_msg_class_t *type,
     HDassert(oh_flags_ptr);
 
     /* Count similar messages */
-    for(idx = 0, sequence = -1, idx_msg = &oh->mesg[0]; idx < oh->nmesgs; idx++, idx_msg++) {
-	if(type->id != idx_msg->type->id)
-            continue;
-	if(++sequence == (int)overwrite)
+    for(idx = 0, idx_msg = &oh->mesg[0]; idx < oh->nmesgs; idx++, idx_msg++)
+	if(type->id == idx_msg->type->id)
             break;
-    } /* end for */
-
-    /* Was the right message found? */
-    if(sequence != (int)overwrite)
-        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "message not found")
+    if(idx == oh->nmesgs)
+        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "message type not found")
 
     /* Check for modifying a constant message */
     if(idx_msg->flags & H5O_MSG_FLAG_CONSTANT)
@@ -437,7 +418,7 @@ done:
  *-------------------------------------------------------------------------
  */
 void *
-H5O_msg_read(const H5O_loc_t *loc, unsigned type_id, int sequence, void *mesg,
+H5O_msg_read(const H5O_loc_t *loc, unsigned type_id, void *mesg,
     hid_t dxpl_id)
 {
     H5O_t *oh = NULL;                   /* Object header to use */
@@ -450,14 +431,13 @@ H5O_msg_read(const H5O_loc_t *loc, unsigned type_id, int sequence, void *mesg,
     HDassert(loc->file);
     HDassert(H5F_addr_defined(loc->addr));
     HDassert(type_id < NELMTS(H5O_msg_class_g));
-    HDassert(sequence >= 0);
 
     /* Get the object header */
     if(NULL == (oh = (H5O_t *)H5AC_protect(loc->file, dxpl_id, H5AC_OHDR, loc->addr, NULL, NULL, H5AC_READ)))
 	HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "unable to load object header")
 
     /* Call the "real" read routine */
-    if((ret_value = H5O_msg_read_real(loc->file, oh, type_id, sequence, mesg, dxpl_id)) == NULL)
+    if((ret_value = H5O_msg_read_real(loc->file, dxpl_id, oh, type_id, mesg)) == NULL)
 	HGOTO_ERROR(H5E_OHDR, H5E_READERROR, NULL, "unable to load object header")
 
 done:
@@ -492,8 +472,8 @@ done:
  *-------------------------------------------------------------------------
  */
 void *
-H5O_msg_read_real(H5F_t *f, H5O_t *oh, unsigned type_id, int sequence,
-    void *mesg, hid_t dxpl_id)
+H5O_msg_read_real(H5F_t *f, hid_t dxpl_id, H5O_t *oh, unsigned type_id,
+    void *mesg)
 {
     const H5O_msg_class_t *type;        /* Actual H5O class type for the ID */
     unsigned       idx;                 /* Message's index in object header */
@@ -507,17 +487,13 @@ H5O_msg_read_real(H5F_t *f, H5O_t *oh, unsigned type_id, int sequence,
     HDassert(type_id < NELMTS(H5O_msg_class_g));
     type = H5O_msg_class_g[type_id];    /* map the type ID to the actual type object */
     HDassert(type);
-    HDassert(sequence >= 0);
 
     /* Scan through the messages looking for the right one */
-    for(idx = 0; idx < oh->nmesgs; idx++) {
-	if(type_id != oh->mesg[idx].type->id)
-            continue;
-	if(--sequence < 0)
+    for(idx = 0; idx < oh->nmesgs; idx++)
+	if(type_id == oh->mesg[idx].type->id)
             break;
-    } /* end for */
-    if(sequence >= 0)
-	HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, NULL, "unable to find object header message")
+    if(idx == oh->nmesgs)
+        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, NULL, "message type not found")
 
     /*
      * Decode the message if necessary.  If the message is shared then retrieve
@@ -821,7 +797,7 @@ done:
  *-------------------------------------------------------------------------
  */
 htri_t
-H5O_msg_exists(H5O_loc_t *loc, unsigned type_id, int sequence, hid_t dxpl_id)
+H5O_msg_exists(H5O_loc_t *loc, unsigned type_id, hid_t dxpl_id)
 {
     H5O_t	*oh = NULL;             /* Object header for location */
     htri_t      ret_value;              /* Return value */
@@ -831,14 +807,13 @@ H5O_msg_exists(H5O_loc_t *loc, unsigned type_id, int sequence, hid_t dxpl_id)
     HDassert(loc);
     HDassert(loc->file);
     HDassert(type_id < NELMTS(H5O_msg_class_g));
-    HDassert(sequence >= 0);
 
     /* Load the object header */
     if(NULL == (oh = (H5O_t *)H5AC_protect(loc->file, dxpl_id, H5AC_OHDR, loc->addr, NULL, NULL, H5AC_READ)))
 	HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, FAIL, "unable to load object header")
 
     /* Call the "real" exists routine */
-    if((ret_value = H5O_msg_exists_oh(oh, type_id, sequence)) < 0)
+    if((ret_value = H5O_msg_exists_oh(oh, type_id)) < 0)
 	HGOTO_ERROR(H5E_OHDR, H5E_READERROR, FAIL, "unable to verify object header message")
 
 done:
@@ -868,11 +843,11 @@ done:
  *-------------------------------------------------------------------------
  */
 htri_t
-H5O_msg_exists_oh(H5O_t *oh, unsigned type_id, int sequence)
+H5O_msg_exists_oh(H5O_t *oh, unsigned type_id)
 {
-    const H5O_msg_class_t *type;    /* Actual H5O class type for the ID */
-    unsigned	u;              /* Local index variable */
-    htri_t      ret_value;      /* Return value */
+    const H5O_msg_class_t *type;        /* Actual H5O class type for the ID */
+    unsigned	u;                      /* Local index variable */
+    htri_t      ret_value = FALSE;      /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5O_msg_exists_oh)
 
@@ -880,19 +855,13 @@ H5O_msg_exists_oh(H5O_t *oh, unsigned type_id, int sequence)
     HDassert(type_id < NELMTS(H5O_msg_class_g));
     type = H5O_msg_class_g[type_id];    /* map the type ID to the actual type object */
     HDassert(type);
-    HDassert(sequence >= 0);
 
     /* Scan through the messages looking for the right one */
-    for(u = 0; u < oh->nmesgs; u++) {
-	if(type->id != oh->mesg[u].type->id)
-            continue;
-	if(--sequence < 0)
-            break;
-    } /* end for */
-
-    /* Set return value */
-    ret_value = (sequence < 0);
+    for(u = 0; u < oh->nmesgs; u++)
+	if(type->id == oh->mesg[u].type->id)
+            HGOTO_DONE(TRUE)
 
+done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5O_msg_exists_oh() */
 
@@ -1038,7 +1007,7 @@ H5O_msg_remove_cb(H5O_t *oh, H5O_mesg_t *mesg/*in,out*/, unsigned sequence,
             udata->nfailed++;
         else {
             /* Convert message into a null message */
-            if(H5O_release_mesg(udata->f, udata->dxpl_id, oh, mesg, TRUE, udata->adj_link) < 0)
+            if(H5O_release_mesg(udata->f, udata->dxpl_id, oh, mesg, udata->adj_link) < 0)
                 HGOTO_ERROR(H5E_OHDR, H5E_CANTDELETE, H5_ITER_ERROR, "unable to release message")
 
             /* Indicate that the object header was modified */
@@ -1698,7 +1667,7 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5O_new_mesg
+ * Function:	H5O_msg_alloc
  *
  * Purpose:	Create a new message in an object header
  *
@@ -1710,15 +1679,14 @@ done:
  *
  *-------------------------------------------------------------------------
  */
-static unsigned
-H5O_new_mesg(H5F_t *f, H5O_t *oh, unsigned *mesg_flags, const H5O_msg_class_t *type,
-    void *mesg, hid_t dxpl_id, unsigned *oh_flags_ptr)
+unsigned
+H5O_msg_alloc(H5F_t *f, hid_t dxpl_id, H5O_t *oh, const H5O_msg_class_t *type,
+    unsigned *mesg_flags, void *mesg, unsigned *oh_flags_ptr)
 {
-    size_t	size;                   /* Size of space allocated for object header */
     htri_t shared_mesg;                 /* Should this message be stored in the Shared Message table? */
     unsigned    ret_value = UFAIL;      /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5O_new_mesg)
+    FUNC_ENTER_NOAPI_NOINIT(H5O_msg_alloc)
 
     /* check args */
     HDassert(f);
@@ -1750,12 +1718,8 @@ H5O_new_mesg(H5F_t *f, H5O_t *oh, unsigned *mesg_flags, const H5O_msg_class_t *t
         } /* end if */
     } /* end else */
 
-    /* Compute the size needed to store the message on disk */
-    if((size = (type->raw_size)(f, FALSE, mesg)) >= H5O_MESG_MAX_SIZE)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, UFAIL, "object header message is too large")
-
     /* Allocate space in the object header for the message */
-    if((ret_value = H5O_alloc(f, dxpl_id, oh, type, size, oh_flags_ptr)) == UFAIL)
+    if((ret_value = H5O_alloc(f, dxpl_id, oh, type, mesg, oh_flags_ptr)) == UFAIL)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, UFAIL, "unable to allocate space for message")
 
     /* Get the message's "creation index", if it has one */
@@ -1767,7 +1731,7 @@ H5O_new_mesg(H5F_t *f, H5O_t *oh, unsigned *mesg_flags, const H5O_msg_class_t *t
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5O_new_mesg() */
+} /* end H5O_msg_alloc() */
 
 
 /*-------------------------------------------------------------------------
@@ -1857,7 +1821,7 @@ H5O_msg_delete(H5F_t *f, hid_t dxpl_id, unsigned type_id, const void *mesg)
     HDassert(type);
 
     /* delete */
-    if((type->del) && (type->del)(f, dxpl_id, mesg, TRUE) < 0)
+    if((type->del) && (type->del)(f, dxpl_id, mesg) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTDELETE, FAIL, "unable to delete file space for object header message")
 
 done:
@@ -1881,7 +1845,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5O_delete_mesg(H5F_t *f, hid_t dxpl_id, H5O_mesg_t *mesg, hbool_t adj_link)
+H5O_delete_mesg(H5F_t *f, hid_t dxpl_id, H5O_mesg_t *mesg)
 {
     const H5O_msg_class_t *type = mesg->type;  /* Type of object to free */
     herr_t ret_value = SUCCEED;   /* Return value */
@@ -1897,11 +1861,11 @@ H5O_delete_mesg(H5F_t *f, hid_t dxpl_id, H5O_mesg_t *mesg, hbool_t adj_link)
         /* Decode the message if necessary. */
         H5O_LOAD_NATIVE(f, dxpl_id, mesg, FAIL)
 
-        if((type->del)(f, dxpl_id, mesg->native, adj_link) < 0)
+        if((type->del)(f, dxpl_id, mesg->native) < 0)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTDELETE, FAIL, "unable to delete file space for object header message")
     } /* end if */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5O_delete_msg() */
+} /* end H5O_delete_mesg() */
 
diff --git a/src/H5Opkg.h b/src/H5Opkg.h
index 0f5a7ae..86ad44b 100644
--- a/src/H5Opkg.h
+++ b/src/H5Opkg.h
@@ -161,17 +161,17 @@
 /* (Only works for messages with decode callback) */
 #define H5O_LOAD_NATIVE(F, DXPL, MSG, ERR)                                        \
     if(NULL == (MSG)->native) {                                               \
-        const H5O_msg_class_t	*decode_type = (MSG)->type;                   \
+        const H5O_msg_class_t	*msg_type = (MSG)->type;                      \
                                                                               \
         /* Decode the message */                                              \
-        HDassert(decode_type->decode);                                        \
-        if(NULL == ((MSG)->native = (decode_type->decode)((F), (DXPL), (MSG)->flags, (MSG)->raw))) \
+        HDassert(msg_type->decode);                                           \
+        if(NULL == ((MSG)->native = (msg_type->decode)((F), (DXPL), (MSG)->flags, (MSG)->raw))) \
             HGOTO_ERROR(H5E_OHDR, H5E_CANTDECODE, ERR, "unable to decode message") \
                                                                               \
         /* Set the message's "creation index", if it has one */		      \
-        if((MSG)->type->set_crt_index) {				      \
+        if(msg_type->set_crt_index) {				      	      \
             /* Set the creation index for the message */		      \
-            if((decode_type->set_crt_index)((MSG)->native, (MSG)->crt_idx) < 0) \
+            if((msg_type->set_crt_index)((MSG)->native, (MSG)->crt_idx) < 0)  \
                 HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, ERR, "unable to set creation index") \
         } /* end if */							      \
     } /* end if */
@@ -189,8 +189,8 @@ struct H5O_msg_class_t {
     size_t	(*raw_size)(const H5F_t *, hbool_t, const void *);/*sizeof encoded message	*/
     herr_t	(*reset)(void *);		/*free nested data structs  */
     herr_t	(*free)(void *);		/*free main data struct  */
-    herr_t	(*del)(H5F_t *, hid_t, const void *, hbool_t); /* Delete space in file referenced by this message */
-    herr_t	(*link)(H5F_t *, hid_t, const void *); /* Increment any links in file reference by this message */
+    herr_t	(*del)(H5F_t *, hid_t, const void *);   /* Delete space in file referenced by this message */
+    herr_t	(*link)(H5F_t *, hid_t, const void *);  /* Increment any links in file reference by this message */
     herr_t	(*set_share)(void*, const H5O_shared_t*);    /* Set shared information */
     htri_t	(*can_share)(const void *);	/* Is message allowed to be shared? */
     herr_t	(*pre_copy_file)(H5F_t *, const void *, hbool_t *, const H5O_copy_t *, void *); /*"pre copy" action when copying native value to file */
@@ -418,19 +418,21 @@ H5_DLLVAR const H5O_obj_class_t H5O_OBJ_DATATYPE[1];
 
 /* Package-local function prototypes */
 H5_DLL herr_t H5O_flush_msgs(H5F_t *f, H5O_t *oh);
-H5_DLL herr_t H5O_delete_mesg(H5F_t *f, hid_t dxpl_id, H5O_mesg_t *mesg,
-    hbool_t adj_link);
+H5_DLL herr_t H5O_delete_mesg(H5F_t *f, hid_t dxpl_id, H5O_mesg_t *mesg);
 H5_DLL const H5O_obj_class_t *H5O_obj_class_real(H5O_t *oh);
 
 /* Object header message routines */
+H5_DLL unsigned H5O_msg_alloc(H5F_t *f, hid_t dxpl_id, H5O_t *oh,
+    const H5O_msg_class_t *type, unsigned *mesg_flags, void *mesg,
+    unsigned *oh_flags_ptr);
 H5_DLL herr_t H5O_msg_append_real(H5F_t *f, hid_t dxpl_id, H5O_t *oh,
     const H5O_msg_class_t *type, unsigned mesg_flags, unsigned update_flags,
     void *mesg, unsigned *oh_flags_ptr);
-H5_DLL void *H5O_msg_read_real(H5F_t *f, H5O_t *oh, unsigned type_id,
-    int sequence, void *mesg, hid_t dxpl_id);
+H5_DLL void *H5O_msg_read_real(H5F_t *f, hid_t dxpl_id, H5O_t *oh,
+    unsigned type_id, void *mesg);
 H5_DLL void *H5O_msg_free_real(const H5O_msg_class_t *type, void *mesg);
 H5_DLL herr_t H5O_msg_free_mesg(H5O_mesg_t *mesg);
-H5_DLL htri_t H5O_msg_exists_oh(struct H5O_t *oh, unsigned type_id, int sequence);
+H5_DLL htri_t H5O_msg_exists_oh(struct H5O_t *oh, unsigned type_id);
 H5_DLL void *H5O_msg_copy_file(const H5O_msg_class_t *type, H5F_t *file_src,
     void *mesg_src, H5F_t *file_dst, hid_t dxpl_id, hbool_t *shared,
     H5O_copy_t *cpy_info, void *udata);
@@ -440,17 +442,17 @@ H5_DLL herr_t H5O_msg_iterate_real(H5F_t *f, H5O_t *oh, const H5O_msg_class_t *t
 
 /* Object header allocation routines */
 H5_DLL unsigned H5O_alloc(H5F_t *f, hid_t dxpl_id, H5O_t *oh,
-    const H5O_msg_class_t *type, size_t size, hbool_t * oh_dirtied_ptr);
+    const H5O_msg_class_t *type, const void *mesg, hbool_t *oh_dirtied_ptr);
 H5_DLL herr_t H5O_condense_header(H5F_t *f, H5O_t *oh, hid_t dxpl_id);
 H5_DLL herr_t H5O_release_mesg(H5F_t *f, hid_t dxpl_id, H5O_t *oh,
-    H5O_mesg_t *mesg, hbool_t delete_mesg, hbool_t adj_link);
+    H5O_mesg_t *mesg, hbool_t adj_link);
 
 /* Shared object operators */
 H5_DLL void * H5O_shared_decode(H5F_t *f, hid_t dxpl_id, const uint8_t *buf, const H5O_msg_class_t *type);
 H5_DLL herr_t H5O_shared_encode(const H5F_t *f, uint8_t *buf/*out*/, const H5O_shared_t *sh_mesg);
 H5_DLL size_t H5O_shared_size(const H5F_t *f, const H5O_shared_t *sh_mesg);
 H5_DLL herr_t H5O_shared_delete(H5F_t *f, hid_t dxpl_id, const H5O_shared_t *sh_mesg,
-    const H5O_msg_class_t *mesg_type, hbool_t adj_link);
+    const H5O_msg_class_t *mesg_type);
 H5_DLL herr_t H5O_shared_link(H5F_t *f, hid_t dxpl_id, const H5O_shared_t *sh_mesg,
     const H5O_msg_class_t *mesg_type);
 H5_DLL herr_t H5O_shared_copy_file(H5F_t *file_src, H5F_t *file_dst, hid_t dxpl_id,
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 76d5dd0..9cb0a0e 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -406,16 +406,15 @@ H5_DLL herr_t H5O_msg_create(H5O_loc_t *loc, unsigned type_id, unsigned mesg_fla
 H5_DLL herr_t H5O_msg_append(H5F_t *f, hid_t dxpl_id, struct H5O_t *oh, unsigned type_id,
     unsigned mesg_flags, unsigned update_flags, void *mesg,
     unsigned *oh_flags_ptr);
-H5_DLL herr_t H5O_msg_write(H5O_loc_t *loc, unsigned type_id, unsigned overwrite,
-    unsigned flags, unsigned update_flags, void *mesg, hid_t dxpl_id);
-H5_DLL void *H5O_msg_read(const H5O_loc_t *loc, unsigned type_id, int sequence,
-    void *mesg, hid_t dxpl_id);
+H5_DLL herr_t H5O_msg_write(H5O_loc_t *loc, unsigned type_id, unsigned flags,
+    unsigned update_flags, void *mesg, hid_t dxpl_id);
+H5_DLL void *H5O_msg_read(const H5O_loc_t *loc, unsigned type_id, void *mesg,
+    hid_t dxpl_id);
 H5_DLL herr_t H5O_msg_reset(unsigned type_id, void *native);
 H5_DLL void *H5O_msg_free(unsigned type_id, void *mesg);
 H5_DLL void *H5O_msg_copy(unsigned type_id, const void *mesg, void *dst);
 H5_DLL int H5O_msg_count(const H5O_loc_t *loc, unsigned type_id, hid_t dxpl_id);
-H5_DLL htri_t H5O_msg_exists(H5O_loc_t *loc, unsigned type_id, int sequence,
-    hid_t dxpl_id);
+H5_DLL htri_t H5O_msg_exists(H5O_loc_t *loc, unsigned type_id, hid_t dxpl_id);
 H5_DLL herr_t H5O_msg_remove(H5O_loc_t *loc, unsigned type_id, int sequence,
     hbool_t adj_link, hid_t dxpl_id);
 H5_DLL herr_t H5O_msg_remove_op(const H5O_loc_t *loc, unsigned type_id, int sequence,
@@ -465,7 +464,7 @@ H5_DLL herr_t H5O_fill_reset_dyn(H5O_fill_t *fill);
 H5_DLL herr_t H5O_fill_convert(H5O_fill_t *fill, H5T_t *type, hbool_t *fill_changed, hid_t dxpl_id);
 
 /* Link operators */
-H5_DLL herr_t H5O_link_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link);
+H5_DLL herr_t H5O_link_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg);
 
 /* Shared message operators */
 H5_DLL herr_t H5O_shared_copy(void *dst, const H5O_shared_t *src);
diff --git a/src/H5Oshared.c b/src/H5Oshared.c
index dafe3d2..ff31b52 100644
--- a/src/H5Oshared.c
+++ b/src/H5Oshared.c
@@ -134,7 +134,7 @@ H5O_shared_read(H5F_t *f, hid_t dxpl_id, const H5O_shared_t *shared,
         HDassert(shared->flags & H5O_COMMITTED_FLAG);
 
         /* Get the shared message from an object header */
-        if(NULL == (ret_value = H5O_msg_read(&(shared->u.oloc), type->id, 0, NULL, dxpl_id)))
+        if(NULL == (ret_value = H5O_msg_read(&(shared->u.oloc), type->id, NULL, dxpl_id)))
             HGOTO_ERROR(H5E_OHDR, H5E_READERROR, NULL, "unable to read message")
     } /* end else */
 
@@ -440,7 +440,7 @@ H5O_shared_size(const H5F_t *f, const H5O_shared_t *sh_mesg)
  */
 herr_t
 H5O_shared_delete(H5F_t *f, hid_t dxpl_id, const H5O_shared_t *sh_mesg,
-    const H5O_msg_class_t *type, hbool_t adj_link)
+    const H5O_msg_class_t *type)
 {
     herr_t ret_value = SUCCEED;   /* Return value */
 
@@ -459,10 +459,9 @@ H5O_shared_delete(H5F_t *f, hid_t dxpl_id, const H5O_shared_t *sh_mesg,
      * be decremented when they're deleted (in H5O_shared_link_adj).
      */
 
-    /* Decrement the reference count on the shared object, if requested */
-    if(adj_link)
-        if(H5O_shared_link_adj(f, dxpl_id, sh_mesg, type, -1) < 0)
-            HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "unable to adjust shared object link count")
+    /* Decrement the reference count on the shared object */
+    if(H5O_shared_link_adj(f, dxpl_id, sh_mesg, type, -1) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "unable to adjust shared object link count")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5Oshared.h b/src/H5Oshared.h
index 96fb938..3a8785b0 100644
--- a/src/H5Oshared.h
+++ b/src/H5Oshared.h
@@ -203,7 +203,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static H5_inline herr_t
-H5O_SHARED_DELETE(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link)
+H5O_SHARED_DELETE(H5F_t *f, hid_t dxpl_id, const void *_mesg)
 {
     const H5O_shared_t *sh_mesg = (const H5O_shared_t *)_mesg;     /* Pointer to shared message portion of actual message */
     herr_t ret_value = SUCCEED;         /* Return value */
@@ -220,13 +220,13 @@ H5O_SHARED_DELETE(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link)
     /* Check for shared message */
     if(H5O_IS_SHARED(sh_mesg->flags)) {
         /* Decrement the reference count on the shared message/object */
-        if(H5O_shared_delete(f, dxpl_id, sh_mesg, H5O_SHARED_TYPE, adj_link) < 0)
+        if(H5O_shared_delete(f, dxpl_id, sh_mesg, H5O_SHARED_TYPE) < 0)
 	    HGOTO_ERROR(H5E_OHDR, H5E_CANTDEC, FAIL, "unable to decrement ref count for shared message")
     } /* end if */
 #ifdef H5O_SHARED_DELETE_REAL
     else {
         /* Decrement the reference count on the native message directly */
-        if(H5O_SHARED_DELETE_REAL(f, dxpl_id, _mesg, adj_link) < 0)
+        if(H5O_SHARED_DELETE_REAL(f, dxpl_id, _mesg) < 0)
 	    HGOTO_ERROR(H5E_OHDR, H5E_CANTDEC, FAIL, "unable to decrement ref count for native message")
     } /* end else */
 #endif /* H5O_SHARED_DELETE_REAL */
diff --git a/src/H5Ostab.c b/src/H5Ostab.c
index 822e7a3..75dc35c 100644
--- a/src/H5Ostab.c
+++ b/src/H5Ostab.c
@@ -40,7 +40,7 @@ static herr_t H5O_stab_encode(H5F_t *f, hbool_t disable_shared, uint8_t *p, cons
 static void *H5O_stab_copy(const void *_mesg, void *_dest);
 static size_t H5O_stab_size(const H5F_t *f, hbool_t disable_shared, const void *_mesg);
 static herr_t H5O_stab_free(void *_mesg);
-static herr_t H5O_stab_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg, hbool_t adj_link);
+static herr_t H5O_stab_delete(H5F_t *f, hid_t dxpl_id, const void *_mesg);
 static void *H5O_stab_copy_file(H5F_t *file_src, void *native_src,
     H5F_t *file_dst, hid_t dxpl_id, H5O_copy_t *cpy_info, void *udata);
 static herr_t H5O_stab_post_copy_file(const H5O_loc_t *src_oloc, const void *mesg_src, H5O_loc_t *dst_oloc,
@@ -269,7 +269,7 @@ H5O_stab_free (void *mesg)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5O_stab_delete(H5F_t *f, hid_t dxpl_id, const void *mesg, hbool_t adj_link)
+H5O_stab_delete(H5F_t *f, hid_t dxpl_id, const void *mesg)
 {
     herr_t ret_value = SUCCEED;   /* Return value */
 
@@ -280,7 +280,7 @@ H5O_stab_delete(H5F_t *f, hid_t dxpl_id, const void *mesg, hbool_t adj_link)
     HDassert(mesg);
 
     /* Free the file space for the symbol table */
-    if(H5G_stab_delete(f, dxpl_id, mesg, adj_link) < 0)
+    if(H5G_stab_delete(f, dxpl_id, mesg) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free symbol table")
 
 done:
diff --git a/src/H5S.c b/src/H5S.c
index 6cfb635..f59a5df 100644
--- a/src/H5S.c
+++ b/src/H5S.c
@@ -1053,7 +1053,7 @@ H5S_write(H5O_loc_t *loc, const H5S_t *ds, hbool_t update_time, hid_t dxpl_id)
         case H5S_NULL:
         case H5S_SCALAR:
         case H5S_SIMPLE:
-            if(H5O_msg_write(loc, H5O_SDSPACE_ID, 0, 0, update_time, &(ds->extent), dxpl_id) < 0)
+            if(H5O_msg_write(loc, H5O_SDSPACE_ID, 0, update_time, &(ds->extent), dxpl_id) < 0)
                 HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, FAIL, "can't update simple dataspace message")
             break;
 
@@ -1146,7 +1146,7 @@ H5S_read(const H5O_loc_t *loc, hid_t dxpl_id)
     if(NULL == (ds = H5FL_CALLOC(H5S_t)))
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
 
-    if(H5O_msg_read(loc, H5O_SDSPACE_ID, 0, &(ds->extent), dxpl_id) == NULL)
+    if(H5O_msg_read(loc, H5O_SDSPACE_ID, &(ds->extent), dxpl_id) == NULL)
         HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, NULL, "unable to load dataspace info from dataset header")
 
     /* Default to entire dataspace being selected */
diff --git a/src/H5T.c b/src/H5T.c
index f0cea46..7981606 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -2455,36 +2455,38 @@ H5T_unregister(H5T_pers_t pers, const char *name, H5T_t *src, H5T_t *dst,
 {
     H5T_path_t	*path = NULL;		/*conversion path		*/
     H5T_soft_t	*soft = NULL;		/*soft conversion information	*/
-    int	nprint=0;		/*number of paths shut down	*/
+    int	nprint = 0;		/*number of paths shut down	*/
     int	i;			/*counter			*/
-    herr_t ret_value=SUCCEED;   /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5T_unregister);
+    FUNC_ENTER_NOAPI_NOINIT(H5T_unregister)
 
     /* Remove matching entries from the soft list */
-    if (H5T_PERS_DONTCARE==pers || H5T_PERS_SOFT==pers) {
-        for (i=H5T_g.nsoft-1; i>=0; --i) {
-            soft = H5T_g.soft+i;
-            assert(soft);
-            if (name && *name && HDstrcmp(name, soft->name)) continue;
-            if (src && src->shared->type!=soft->src) continue;
-            if (dst && dst->shared->type!=soft->dst) continue;
-            if (func && func!=soft->func) continue;
-
-            HDmemmove(H5T_g.soft+i, H5T_g.soft+i+1,
-                  (H5T_g.nsoft-(i+1)) * sizeof(H5T_soft_t));
+    if(H5T_PERS_DONTCARE == pers || H5T_PERS_SOFT == pers) {
+        for(i = H5T_g.nsoft - 1; i >= 0; --i) {
+            soft = H5T_g.soft + i;
+            HDassert(soft);
+            if(name && *name && HDstrcmp(name, soft->name))
+                continue;
+            if(src && src->shared->type != soft->src)
+                continue;
+            if(dst && dst->shared->type != soft->dst)
+                continue;
+            if(func && func != soft->func)
+                continue;
+
+            HDmemmove(H5T_g.soft + i, H5T_g.soft + i + 1, (H5T_g.nsoft - (i + 1)) * sizeof(H5T_soft_t));
             --H5T_g.nsoft;
-        }
-    }
+        } /* end for */
+    } /* end if */
 
     /* Remove matching conversion paths, except no-op path */
-    for (i=H5T_g.npaths-1; i>0; --i) {
+    for(i = H5T_g.npaths - 1; i > 0; --i) {
         path = H5T_g.path[i];
-        assert(path);
+        HDassert(path);
 
         /* Not a match */
-        if (((H5T_PERS_SOFT==pers && path->is_hard) ||
-                    (H5T_PERS_HARD==pers && !path->is_hard)) ||
+        if(((H5T_PERS_SOFT == pers && path->is_hard) ||
+                    (H5T_PERS_HARD == pers && !path->is_hard)) ||
                 (name && *name && HDstrcmp(name, path->name)) ||
                 (src && H5T_cmp(src, path->src, FALSE)) ||
                 (dst && H5T_cmp(dst, path->dst, FALSE)) ||
@@ -2500,17 +2502,16 @@ H5T_unregister(H5T_pers_t pers, const char *name, H5T_t *src, H5T_t *dst,
         } /* end if */
         else {
             /* Remove from table */
-            HDmemmove(H5T_g.path+i, H5T_g.path+i+1,
-                  (H5T_g.npaths-(i+1))*sizeof(H5T_path_t*));
+            HDmemmove(H5T_g.path + i, H5T_g.path + i + 1, (H5T_g.npaths - (i + 1)) * sizeof(H5T_path_t*));
             --H5T_g.npaths;
 
             /* Shut down path */
             H5T_print_stats(path, &nprint);
             path->cdata.command = H5T_CONV_FREE;
-            if ((path->func)(FAIL, FAIL, &(path->cdata),
-                    (size_t)0, (size_t)0, (size_t)0, NULL, NULL, dxpl_id)<0) {
+            if((path->func)(FAIL, FAIL, &(path->cdata),
+                    (size_t)0, (size_t)0, (size_t)0, NULL, NULL, dxpl_id) < 0) {
 #ifdef H5T_DEBUG
-                if (H5DEBUG(T)) {
+                if(H5DEBUG(T)) {
                     fprintf(H5DEBUG(T), "H5T: conversion function 0x%08lx failed "
                             "to free private data for %s (ignored)\n",
                             (unsigned long)(path->func), path->name);
@@ -2524,9 +2525,8 @@ H5T_unregister(H5T_pers_t pers, const char *name, H5T_t *src, H5T_t *dst,
         } /* end else */
     } /* end for */
 
-done:
-    FUNC_LEAVE_NOAPI(ret_value);
-}   /* end H5T_unregister() */
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5T_unregister() */
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Tcommit.c b/src/H5Tcommit.c
index bc213ae..81bac02 100644
--- a/src/H5Tcommit.c
+++ b/src/H5Tcommit.c
@@ -786,7 +786,7 @@ H5T_open_oid(H5G_loc_t *loc, hid_t dxpl_id)
 
     if(H5O_open(loc->oloc) < 0)
 	HGOTO_ERROR(H5E_DATATYPE, H5E_CANTOPENOBJ, NULL, "unable to open named datatype")
-    if(NULL == (dt = H5O_msg_read(loc->oloc, H5O_DTYPE_ID, 0, NULL, dxpl_id)))
+    if(NULL == (dt = H5O_msg_read(loc->oloc, H5O_DTYPE_ID, NULL, dxpl_id)))
 	HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, NULL, "unable to load type message from object header")
 
     /* Mark the type as named and open */
diff --git a/src/H5Toh.c b/src/H5Toh.c
index f6854e9..784e127 100644
--- a/src/H5Toh.c
+++ b/src/H5Toh.c
@@ -98,7 +98,7 @@ H5O_dtype_isa(struct H5O_t *oh)
 
     HDassert(oh);
 
-    if((ret_value = H5O_msg_exists_oh(oh, H5O_DTYPE_ID, 0)) < 0)
+    if((ret_value = H5O_msg_exists_oh(oh, H5O_DTYPE_ID)) < 0)
 	HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "unable to read object header")
 
 done:
diff --git a/src/H5Tpkg.h b/src/H5Tpkg.h
index 9232196..61dd745 100644
--- a/src/H5Tpkg.h
+++ b/src/H5Tpkg.h
@@ -120,7 +120,7 @@
  * compiler tries to do the conversion.  For Cygwin, compiler doesn't do rounding correctly.
  * Mac OS 10.4 gives some incorrect result. */
 #if (H5_WANT_DATA_ACCURACY && H5_ULLONG_TO_FP_CAST_WORKS && H5_ULONG_TO_FP_BOTTOM_BIT_ACCURATE && \
-    H5_ULLONG_TO_LDOUBLE_PRECISION && defined(H5_LLONG_TO_LDOUBLE_CORRECT)) || (!H5_WANT_DATA_ACCURACY && \
+    defined(H5_ULLONG_TO_LDOUBLE_PRECISION) && defined(H5_LLONG_TO_LDOUBLE_CORRECT)) || (!H5_WANT_DATA_ACCURACY && \
     H5_ULLONG_TO_FP_CAST_WORKS)
 #define H5T_CONV_INTERNAL_ULLONG_LDOUBLE         1
 #endif
diff --git a/test/ohdr.c b/test/ohdr.c
index 67d07a6..97501ef 100644
--- a/test/ohdr.c
+++ b/test/ohdr.c
@@ -105,7 +105,7 @@ main(void)
 	H5Eprint_stack(H5E_DEFAULT, stdout);
 	goto error;
     }
-    if (NULL==H5O_msg_read(&oh_loc, H5O_MTIME_NEW_ID, 0, &ro, H5P_DATASET_XFER_DEFAULT)) {
+    if(NULL == H5O_msg_read(&oh_loc, H5O_MTIME_NEW_ID, &ro, H5P_DATASET_XFER_DEFAULT)) {
 	H5_FAILED();
 	H5Eprint_stack(H5E_DEFAULT, stdout);
 	goto error;
@@ -123,7 +123,7 @@ main(void)
      */
     TESTING("message modification");
     time_new = 33333333;
-    if (H5O_msg_write(&oh_loc, H5O_MTIME_NEW_ID, 0, 0, 0, &time_new, H5P_DATASET_XFER_DEFAULT)<0) {
+    if (H5O_msg_write(&oh_loc, H5O_MTIME_NEW_ID, 0, 0, &time_new, H5P_DATASET_XFER_DEFAULT)<0) {
 	H5_FAILED();
 	H5Eprint_stack(H5E_DEFAULT, stdout);
 	goto error;
@@ -133,7 +133,7 @@ main(void)
 	H5Eprint_stack(H5E_DEFAULT, stdout);
 	goto error;
     }
-    if (NULL==H5O_msg_read(&oh_loc, H5O_MTIME_NEW_ID, 0, &ro, H5P_DATASET_XFER_DEFAULT)) {
+    if(NULL == H5O_msg_read(&oh_loc, H5O_MTIME_NEW_ID, &ro, H5P_DATASET_XFER_DEFAULT)) {
 	H5_FAILED();
 	H5Eprint_stack(H5E_DEFAULT, stdout);
 	goto error;
@@ -148,62 +148,6 @@ main(void)
 
 
     /*
-     * Test creation of a second message of the same type.
-     */
-    TESTING("duplicate message creation");
-    time_new = 55555555;
-    if(H5O_msg_create(&oh_loc, H5O_MTIME_NEW_ID, 0, 0, &time_new, H5P_DATASET_XFER_DEFAULT) < 0) {
-	H5_FAILED();
-	H5Eprint_stack(H5E_DEFAULT, stdout);
-	goto error;
-    }
-    if (H5AC_flush(f, H5P_DATASET_XFER_DEFAULT, TRUE)<0) {
-	H5_FAILED();
-	H5Eprint_stack(H5E_DEFAULT, stdout);
-	goto error;
-    }
-    if (NULL==H5O_msg_read(&oh_loc, H5O_MTIME_NEW_ID, 1, &ro, H5P_DATASET_XFER_DEFAULT)) {
-	H5_FAILED();
-	H5Eprint_stack(H5E_DEFAULT, stdout);
-	goto error;
-    }
-    if (ro!=time_new) {
-	H5_FAILED();
-	HDfprintf(stdout, "    got: {%ld}\n", (long)ro);
-	HDfprintf(stdout, "    ans: {%ld}\n", (long)time_new);
-	goto error;
-    }
-    PASSED();
-
-    /*
-     * Test modification of the second message with a symbol table.
-     */
-    TESTING("duplicate message modification");
-    time_new = 77777777;
-    if (H5O_msg_write(&oh_loc, H5O_MTIME_NEW_ID, 1, 0, 0, &time_new, H5P_DATASET_XFER_DEFAULT)<0) {
-	H5_FAILED();
-	H5Eprint_stack(H5E_DEFAULT, stdout);
-	goto error;
-    }
-    if (H5AC_flush(f, H5P_DATASET_XFER_DEFAULT, TRUE)<0) {
-	H5_FAILED();
-	H5Eprint_stack(H5E_DEFAULT, stdout);
-	goto error;
-    }
-    if (NULL==H5O_msg_read(&oh_loc, H5O_MTIME_NEW_ID, 1, &ro, H5P_DATASET_XFER_DEFAULT)) {
-	H5_FAILED();
-	H5Eprint_stack(H5E_DEFAULT, stdout);
-	goto error;
-    }
-    if (ro!=time_new) {
-	H5_FAILED();
-	HDfprintf(stdout, "    got: {%ld}\n", (long)ro);
-	HDfprintf(stdout, "    ans: {%ld}\n", (long)time_new);
-	goto error;
-    }
-    PASSED();
-
-    /*
      * Test creation of a bunch of messages one after another to see
      * what happens when the object header overflows in core.
      * (Use 'old' MTIME message here, because it is large enough to be
@@ -261,13 +205,13 @@ main(void)
 	H5Eprint_stack(H5E_DEFAULT, stdout);
 	goto error;
     }
-    if (H5O_msg_read(&oh_loc, H5O_MTIME_NEW_ID, 0, &ro, H5P_DATASET_XFER_DEFAULT)) {
+    if(H5O_msg_read(&oh_loc, H5O_MTIME_NEW_ID, &ro, H5P_DATASET_XFER_DEFAULT)) {
 	H5_FAILED();
 	puts("    H5O_msg_read() should have failed but didn't");
 	H5Eclear_stack(H5E_DEFAULT);
 	goto error;
     }
-    if (H5O_msg_read(&oh_loc, H5O_MTIME_ID, 0, &ro, H5P_DATASET_XFER_DEFAULT)) {
+    if(H5O_msg_read(&oh_loc, H5O_MTIME_ID, &ro, H5P_DATASET_XFER_DEFAULT)) {
 	H5_FAILED();
 	puts("    H5O_msg_read() should have failed but didn't");
 	H5Eclear_stack(H5E_DEFAULT);