Merge branch 'develop' into bugfix/intel_warnings

54 files changed, 972 insertions, 394 deletions

diff --git a/src/H5Cdbg.c b/src/H5Cdbg.c
index cb1d0e2..1f55e86 100644
--- a/src/H5Cdbg.c
+++ b/src/H5Cdbg.c
@@ -319,8 +319,9 @@ H5C_dump_cache_skip_list(H5C_t * cache_ptr, char * calling_fcn)
                (int)(entry_ptr->is_dirty),
                entry_ptr->type->name);
 
-            HDfprintf(stdout, "		node_ptr = %p, item = %p\n",
-                      node_ptr, H5SL_item(node_ptr));
+            HDfprintf(stdout, "		node_ptr = 0x%llx, item = %p\n",
+                      (unsigned long long)node_ptr,
+                      H5SL_item(node_ptr));
 
             /* increment node_ptr before we delete its target */
             node_ptr = H5SL_next(node_ptr);
diff --git a/src/H5Cpkg.h b/src/H5Cpkg.h
index b8648f0..9156c0d 100644
--- a/src/H5Cpkg.h
+++ b/src/H5Cpkg.h
@@ -4694,7 +4694,7 @@ struct H5C_t {
     uint32_t                    num_last_entries;
 #if H5C_DO_SANITY_CHECKS
     int32_t			slist_len_increase;
-    int64_t			slist_size_increase;
+    ssize_t			slist_size_increase;
 #endif /* H5C_DO_SANITY_CHECKS */
 
     /* Fields for maintaining list of tagged entries */
diff --git a/src/H5D.c b/src/H5D.c
index a2e6f0a..7c68127 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -736,7 +736,7 @@ herr_t
 H5Dvlen_get_buf_size(hid_t dataset_id, hid_t type_id, hid_t space_id,
         hsize_t *size)
 {
-    H5D_vlen_bufsize_t vlen_bufsize = {0, 0, 0, 0, 0, 0};
+    H5D_vlen_bufsize_t vlen_bufsize = {NULL, H5I_INVALID_HID, H5I_INVALID_HID, NULL, NULL, 0, H5P_DATASET_XFER_DEFAULT};
     H5VL_object_t  *vol_obj;       /* Dataset for this operation */
     H5S_t *mspace = NULL;       /* Memory dataspace */
     char bogus;                 /* bogus value to pass to H5Diterate() */
@@ -763,8 +763,6 @@ H5Dvlen_get_buf_size(hid_t dataset_id, hid_t type_id, hid_t space_id,
 
     /* Save the dataset */
     vlen_bufsize.dset_vol_obj = vol_obj;
-    vlen_bufsize.fspace_id = H5I_INVALID_HID;
-    vlen_bufsize.mspace_id = H5I_INVALID_HID;
 
     /* Get a copy of the dataset's dataspace */
     if(H5VL_dataset_get(vol_obj, H5VL_DATASET_GET_SPACE, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &vlen_bufsize.fspace_id) < 0)
@@ -786,6 +784,22 @@ H5Dvlen_get_buf_size(hid_t dataset_id, hid_t type_id, hid_t space_id,
     if(H5CX_set_vlen_alloc_info(H5D__vlen_get_buf_size_alloc, &vlen_bufsize, NULL, NULL) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set VL data allocation routine")
 
+    /* If we are not using the native VOL connector we must also set this
+     * property on the DXPL since the context is not visible to the connector
+     * and will be ignored if the connector re-enters the library */
+    if(vol_obj->connector->cls->value != H5VL_NATIVE_VALUE) {
+        H5P_genplist_t *dxpl;
+
+        if(NULL == (dxpl = (H5P_genplist_t *)H5I_object(H5P_DATASET_XFER_DEFAULT)))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get default DXPL")
+        if((vlen_bufsize.dxpl_id = H5P_copy_plist(dxpl, TRUE)) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTCOPY, H5I_INVALID_HID, "can't copy property list");
+        if(NULL == (dxpl = (H5P_genplist_t *)H5I_object(vlen_bufsize.dxpl_id)))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get copied DXPL")
+        if(H5P_set_vlen_mem_manager(dxpl, H5D__vlen_get_buf_size_alloc, &vlen_bufsize, NULL, NULL) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set VL data allocation routine on DXPL")
+    } /* end if */
+
     /* Set the initial number of bytes required */
     vlen_bufsize.size = 0;
 
@@ -805,14 +819,17 @@ done:
         if(mspace && H5S_close(mspace) < 0)
             HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "unable to release dataspace")
 
-    if(vlen_bufsize.fspace_id && H5I_dec_app_ref(vlen_bufsize.fspace_id) < 0)
-        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTDEC, FAIL, "problem freeing id")
-    if(vlen_bufsize.mspace_id && H5I_dec_app_ref(vlen_bufsize.mspace_id) < 0)
-        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTDEC, FAIL, "problem freeing id")
+    if(vlen_bufsize.fspace_id >= 0 && H5I_dec_app_ref(vlen_bufsize.fspace_id) < 0)
+        HDONE_ERROR(H5E_DATASPACE, H5E_CANTDEC, FAIL, "problem freeing id")
+    if(vlen_bufsize.mspace_id >= 0 && H5I_dec_app_ref(vlen_bufsize.mspace_id) < 0)
+        HDONE_ERROR(H5E_DATASPACE, H5E_CANTDEC, FAIL, "problem freeing id")
     if(vlen_bufsize.fl_tbuf != NULL)
         vlen_bufsize.fl_tbuf = H5FL_BLK_FREE(vlen_fl_buf, vlen_bufsize.fl_tbuf);
     if(vlen_bufsize.vl_tbuf != NULL)
         vlen_bufsize.vl_tbuf = H5FL_BLK_FREE(vlen_vl_buf, vlen_bufsize.vl_tbuf);
+    if(vlen_bufsize.dxpl_id != H5P_DATASET_XFER_DEFAULT)
+        if(H5I_dec_app_ref(vlen_bufsize.dxpl_id) < 0)
+            HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, FAIL, "can't close property list")
 
     FUNC_LEAVE_API(ret_value)
 }   /* end H5Dvlen_get_buf_size() */
diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index 62303bb..2f95024 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -284,8 +284,7 @@ static int H5D__chunk_format_convert_cb(const H5D_chunk_rec_t *chunk_rec, void *
 static herr_t H5D__chunk_set_info_real(H5O_layout_chunk_t *layout, unsigned ndims,
     const hsize_t *curr_dims, const hsize_t *max_dims);
 static void *H5D__chunk_mem_alloc(size_t size, const H5O_pline_t *pline);
-static void *H5D__chunk_mem_xfree(void *chk, void *pline);
-static void H5D__chunk_mem_xfree_wrapper(void *chk, void *pline);
+static void *H5D__chunk_mem_xfree(void *chk, const void *pline);
 static void *H5D__chunk_mem_realloc(void *chk, size_t size,
     const H5O_pline_t *pline);
 static herr_t H5D__chunk_cinfo_cache_reset(H5D_chunk_cached_t *last);
@@ -1101,10 +1100,14 @@ H5D__chunk_io_init(const H5D_io_info_t *io_info, const H5D_type_info_t *type_inf
     H5D_chunk_map_t *fm)
 {
     const H5D_t *dataset = io_info->dset;     /* Local pointer to dataset info */
+    H5S_t *tmp_mspace = NULL;   /* Temporary memory dataspace */
     hssize_t old_offset[H5O_LAYOUT_NDIMS];  /* Old selection offset */
     htri_t file_space_normalized = FALSE;   /* File dataspace was normalized */
+    H5T_t *file_type = NULL;    /* Temporary copy of file datatype for iteration */
+    hbool_t iter_init = FALSE;  /* Selection iteration info has been initialized */
     unsigned f_ndims;           /* The number of dimensions of the file's dataspace */
     int sm_ndims;               /* The number of dimensions of the memory buffer's dataspace (signed) */
+    char bogus;                 /* "bogus" buffer to pass to selection iterator */
     unsigned u;                 /* Local index variable */
     herr_t ret_value = SUCCEED;	/* Return value		*/
 
@@ -1428,7 +1431,7 @@ H5D__chunk_mem_alloc(size_t size, const H5O_pline_t *pline)
  *-------------------------------------------------------------------------
  */
 static void *
-H5D__chunk_mem_xfree(void *chk, void *_pline)
+H5D__chunk_mem_xfree(void *chk, const void *_pline)
 {
     const H5O_pline_t *pline = (const H5O_pline_t *)_pline;
 
@@ -1444,17 +1447,6 @@ H5D__chunk_mem_xfree(void *chk, void *_pline)
     FUNC_LEAVE_NOAPI(NULL)
 } /* H5D__chunk_mem_xfree() */
 
-/* H5D__chunk_mem_xfree_wrapper() safely adapts the type of
- * H5D__chunk_mem_xfree() to an H5MM_free_t callback, without making
- * compilers warn.  It is used with H5D__chunk_mem_xfree_wrapper(), for
- * example.
- */
-static void
-H5D__chunk_mem_xfree_wrapper(void *chk, void *_pline)
-{
-    (void)H5D__chunk_mem_xfree(chk, _pline);
-}
-
 
 /*-------------------------------------------------------------------------
  * Function:    H5D__chunk_mem_realloc
@@ -2147,6 +2139,12 @@ H5D__create_chunk_mem_map_1d(const H5D_chunk_map_t *fm)
 {
     H5D_chunk_info_t *chunk_info;           /* Pointer to chunk information */
     H5SL_node_t *curr_node;                 /* Current node in skip list */
+    hsize_t     file_sel_start[H5S_MAX_RANK];    /* Offset of low bound of file selection */
+    hsize_t     file_sel_end[H5S_MAX_RANK]; /* Offset of high bound of file selection */
+    hsize_t     mem_sel_start[H5S_MAX_RANK]; /* Offset of low bound of file selection */
+    hsize_t     mem_sel_end[H5S_MAX_RANK];  /* Offset of high bound of file selection */
+    hssize_t    adjust[H5S_MAX_RANK];       /* Adjustment to make to all file chunks */
+    unsigned    u;                          /* Local index variable */
     herr_t	ret_value = SUCCEED;        /* Return value */
 
     FUNC_ENTER_STATIC
@@ -2171,18 +2169,17 @@ H5D__create_chunk_mem_map_1d(const H5D_chunk_map_t *fm)
         chunk_info->mspace_shared = TRUE;
     } /* end if */
     else {
+        HDassert(fm->m_ndims == 1);
         hsize_t     mem_sel_start[H5S_MAX_RANK]; /* Offset of low bound of file selection */
         hsize_t     mem_sel_end[H5S_MAX_RANK];  /* Offset of high bound of file selection */
 
-        HDassert(fm->m_ndims == 1);
-
         if(H5S_SELECT_BOUNDS(fm->mem_space, mem_sel_start, mem_sel_end) < 0)
             HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, "can't get file selection bound info")
 
         /* Iterate over each chunk in the chunk list */
         curr_node = H5SL_first(fm->sel_chunks);
         while(curr_node) {
-            hsize_t    schunk_points;          /* Number of elements in chunk selection */
+            hssize_t    schunk_points;          /* Number of elements in chunk selection */
             hsize_t     tmp_count = 1;
 
             /* Get pointer to chunk's information */
@@ -4453,7 +4450,7 @@ H5D__chunk_allocate(const H5D_io_info_t *io_info, hbool_t full_overwrite, hsize_
         /* (delay allocating fill buffer for VL datatypes until refilling) */
         /* (casting away const OK - QAK) */
         if(H5D__fill_init(&fb_info, NULL, (H5MM_allocate_t)H5D__chunk_mem_alloc,
-                (void *)pline, H5D__chunk_mem_xfree_wrapper, (void *)pline,
+                (void *)pline, (H5MM_free_t)H5D__chunk_mem_xfree, (void *)pline,
                 &dset->shared->dcpl_cache.fill, dset->shared->type,
                 dset->shared->type_id, (size_t)0, orig_chunk_size) < 0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't initialize fill buffer info")
@@ -7154,6 +7151,7 @@ H5D__get_num_chunks(const H5D_t *dset, const H5S_t H5_ATTR_UNUSED *space, hsize_
     hsize_t            num_chunks = 0;          /* Number of written chunks */
     H5D_rdcc_ent_t     *ent;                    /* Cache entry  */
     const H5D_rdcc_t   *rdcc = NULL;            /* Raw data chunk cache */
+    const H5O_layout_t *layout;                 /* Dataset layout */
     herr_t             ret_value = SUCCEED;     /* Return value */
 
     FUNC_ENTER_PACKAGE_TAG(dset->oloc.addr)
@@ -7163,6 +7161,7 @@ H5D__get_num_chunks(const H5D_t *dset, const H5S_t H5_ATTR_UNUSED *space, hsize_
     HDassert(space);
     HDassert(nchunks);
 
+    layout = &(dset->shared->layout);    /* Dataset layout */
     rdcc = &(dset->shared->cache.chunk); /* raw data chunk cache */
     HDassert(rdcc);
 
diff --git a/src/H5Dint.c b/src/H5Dint.c
index ee90db2..c3d4398 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -49,7 +49,7 @@
 /********************/
 
 /* General stuff */
-static H5D_shared_t *H5D__new(hid_t dcpl_id, hbool_t creating, hbool_t vl_type);
+static H5D_shared_t *H5D__new(hid_t dcpl_id, hid_t dapl, hbool_t creating, hbool_t vl_type);
 static herr_t H5D__init_type(H5F_t *file, const H5D_t *dset, hid_t type_id, const H5T_t *type);
 static herr_t H5D__cache_dataspace_info(const H5D_t *dset);
 static herr_t H5D__init_space(H5F_t *file, const H5D_t *dset, const H5S_t *space);
@@ -465,7 +465,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static H5D_shared_t *
-H5D__new(hid_t dcpl_id, hbool_t creating, hbool_t vl_type)
+H5D__new(hid_t dcpl_id, hid_t dapl_id, hbool_t creating, hbool_t vl_type)
 {
     H5D_shared_t    *new_dset = NULL;   /* New dataset object */
     H5P_genplist_t  *plist;             /* Property list created */
@@ -496,6 +496,19 @@ H5D__new(hid_t dcpl_id, hbool_t creating, hbool_t vl_type)
         new_dset->dcpl_id = H5P_copy_plist(plist, FALSE);
     } /* end else */
 
+    if(!vl_type && creating && dapl_id == H5P_DATASET_ACCESS_DEFAULT) {
+        if(H5I_inc_ref(dapl_id, FALSE) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTINC, NULL, "can't increment default DAPL ID")
+        new_dset->dapl_id = dapl_id;
+    } /* end if */
+    else {
+        /* Get the property list */
+        if(NULL == (plist = (H5P_genplist_t *)H5I_object(dapl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a property list")
+
+        new_dset->dapl_id = H5P_copy_plist(plist, FALSE);
+    } /* end else */
+
     /* Set return value */
     ret_value = new_dset;
 
@@ -504,6 +517,8 @@ done:
         if(new_dset != NULL) {
             if(new_dset->dcpl_id != 0 && H5I_dec_ref(new_dset->dcpl_id) < 0)
                 HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, NULL, "can't decrement temporary datatype ID")
+            if(new_dset->dapl_id != 0 && H5I_dec_ref(new_dset->dapl_id) < 0)
+                HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, NULL, "can't decrement temporary datatype ID")
             new_dset = H5FL_FREE(H5D_shared_t, new_dset);
         } /* end if */
 
@@ -1225,9 +1240,8 @@ H5D__create(H5F_t *file, hid_t type_id, const H5S_t *space, hid_t dcpl_id,
     H5G_loc_reset(&dset_loc);
 
     /* Initialize the shared dataset space */
-    if(NULL == (new_dset->shared = H5D__new(dcpl_id, TRUE, has_vl_type)))
+    if(NULL == (new_dset->shared = H5D__new(dcpl_id, dapl_id, TRUE, has_vl_type)))
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
-
     /* Copy & initialize datatype for dataset */
     if(H5D__init_type(file, new_dset, type_id, type) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "can't copy datatype")
@@ -1320,14 +1334,14 @@ H5D__create(H5F_t *file, hid_t type_id, const H5S_t *space, hid_t dcpl_id,
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to construct layout information")
 
     /* Update the dataset's object header info. */
-    if(H5D__update_oh_info(file, new_dset, dapl_id) < 0)
+    if(H5D__update_oh_info(file, new_dset, new_dset->shared->dapl_id) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "can't update the metadata cache")
 
     /* Indicate that the layout information was initialized */
     layout_init = TRUE;
 
     /* Set up append flush parameters for the dataset */
-    if(H5D__append_flush_setup(new_dset, dapl_id) < 0)
+    if(H5D__append_flush_setup(new_dset, new_dset->shared->dapl_id) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to set up flush append property")
 
     /* Set the external file prefix */
@@ -1382,6 +1396,8 @@ done:
             } /* end if */
             if(new_dset->shared->dcpl_id != 0 && H5I_dec_ref(new_dset->shared->dcpl_id) < 0)
                 HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, NULL, "unable to decrement ref count on property list")
+            if(new_dset->shared->dapl_id != 0 && H5I_dec_ref(new_dset->shared->dapl_id) < 0)
+                HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, NULL, "unable to decrement ref count on property list")
             new_dset->shared->extfile_prefix = (char *)H5MM_xfree(new_dset->shared->extfile_prefix);
             new_dset->shared->vds_prefix = (char *)H5MM_xfree(new_dset->shared->vds_prefix);
             new_dset->shared = H5FL_FREE(H5D_shared_t, new_dset->shared);
@@ -1686,7 +1702,7 @@ H5D__open_oid(H5D_t *dataset, hid_t dapl_id)
     HDassert(dataset);
 
     /* (Set the 'vl_type' parameter to FALSE since it doesn't matter from here) */
-    if(NULL == (dataset->shared = H5D__new(H5P_DATASET_CREATE_DEFAULT, FALSE, FALSE)))
+    if(NULL == (dataset->shared = H5D__new(H5P_DATASET_CREATE_DEFAULT, dapl_id, FALSE, FALSE)))
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
 
     /* Open the dataset object */
@@ -1968,12 +1984,13 @@ H5D_close(H5D_t *dataset)
             if(H5AC_cork(dataset->oloc.file, dataset->oloc.addr, H5AC__UNCORK, NULL) < 0)
                 HDONE_ERROR(H5E_DATASET, H5E_CANTUNCORK, FAIL, "unable to uncork an object")
 
-        /* Release datatype, dataspace and creation property list -- there isn't
+        /* Release datatype, dataspace and creation and access property lists -- there isn't
          * much we can do if one of these fails, so we just continue.
          */
         free_failed |= (H5I_dec_ref(dataset->shared->type_id) < 0) ||
                           (H5S_close(dataset->shared->space) < 0) ||
-                          (H5I_dec_ref(dataset->shared->dcpl_id) < 0);
+                          (H5I_dec_ref(dataset->shared->dcpl_id) < 0) ||
+                          (H5I_dec_ref(dataset->shared->dapl_id) < 0);
 
         /* Remove the dataset from the list of opened objects in the file */
         if(H5FO_top_decr(dataset->oloc.file, dataset->oloc.addr) < 0)
@@ -2622,7 +2639,7 @@ H5D__vlen_get_buf_size(void H5_ATTR_UNUSED *elem, hid_t type_id,
         HGOTO_ERROR(H5E_DATASET, H5E_CANTCREATE, FAIL, "can't select point")
 
     /* Read in the point (with the custom VL memory allocator) */
-    if(H5VL_dataset_read(vol_obj, type_id, vlen_bufsize->mspace_id, vlen_bufsize->fspace_id, H5P_DATASET_XFER_DEFAULT, vlen_bufsize->fl_tbuf, H5_REQUEST_NULL) < 0)
+    if(H5VL_dataset_read(vol_obj, type_id, vlen_bufsize->mspace_id, vlen_bufsize->fspace_id, vlen_bufsize->dxpl_id, vlen_bufsize->fl_tbuf, H5_REQUEST_NULL) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "can't read point")
 
 done:
@@ -3428,22 +3445,26 @@ done:
 hid_t
 H5D_get_access_plist(const H5D_t *dset)
 {
-    H5P_genplist_t      *old_plist;     /* Default DAPL */
+    H5P_genplist_t      *old_plist;     /* Stored DAPL from dset */
     H5P_genplist_t      *new_plist;     /* New DAPL */
+    H5P_genplist_t      *def_fapl;      /* Default FAPL */
+    H5D_append_flush_t  def_append_flush_info = {0};  /* Default append flush property */
+    H5D_rdcc_t          def_chunk_info;               /* Default chunk cache property */
     hid_t               new_dapl_id = FAIL;
     hid_t               ret_value = FAIL;
 
     FUNC_ENTER_NOAPI_NOINIT
 
-    /* Make a copy of the default dataset access property list */
-    if(NULL == (old_plist = (H5P_genplist_t *)H5I_object(H5P_LST_DATASET_ACCESS_ID_g)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
+    /* Make a copy of the dataset's dataset access property list */
+    if(NULL == (old_plist = (H5P_genplist_t *)H5I_object(dset->shared->dapl_id)))
+        HGOTO_ERROR(H5E_DATASET, H5E_BADTYPE, FAIL, "can't get property list")
     if((new_dapl_id = H5P_copy_plist(old_plist, TRUE)) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINIT, FAIL, "can't copy dataset access property list")
     if(NULL == (new_plist = (H5P_genplist_t *)H5I_object(new_dapl_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
 
-    /* If the dataset is chunked then copy the rdcc & append flush parameters */
+    /* If the dataset is chunked then copy the rdcc & append flush parameters.
+     * Otherwise, use the default values. */
     if(dset->shared->layout.type == H5D_CHUNKED) {
         if(H5P_set(new_plist, H5D_ACS_DATA_CACHE_NUM_SLOTS_NAME, &(dset->shared->cache.chunk.nslots)) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set data cache number of slots")
@@ -3453,7 +3474,33 @@ H5D_get_access_plist(const H5D_t *dset)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set preempt read chunks")
         if(H5P_set(new_plist, H5D_ACS_APPEND_FLUSH_NAME, &dset->shared->append_flush) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set append flush property")
-    } /* end if */
+    } else {
+        /* Get the default FAPL */
+        if(NULL == (def_fapl = (H5P_genplist_t *)H5I_object(H5P_LST_FILE_ACCESS_ID_g)))
+            HGOTO_ERROR(H5E_DATASET, H5E_BADTYPE, FAIL, "not a property list")
+
+        /* Set the data cache number of slots to the value of the default FAPL */
+        if (H5P_get(def_fapl, H5D_ACS_DATA_CACHE_NUM_SLOTS_NAME, &def_chunk_info.nslots) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET,FAIL, "can't get data number of slots");
+        if(H5P_set(new_plist, H5D_ACS_DATA_CACHE_NUM_SLOTS_NAME, &def_chunk_info.nslots) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set data cache number of slots")
+
+        /* Set the data cache byte size to the value of the default FAPL */
+        if (H5P_get(def_fapl, H5D_ACS_DATA_CACHE_BYTE_SIZE_NAME, &def_chunk_info.nbytes_max) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET,FAIL, "can't get data cache byte size");
+        if(H5P_set(new_plist, H5D_ACS_DATA_CACHE_BYTE_SIZE_NAME, &def_chunk_info.nbytes_max) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set data cache byte size")
+
+        /* Set the preempt read chunks property to the value of the default FAPL */
+        if (H5P_get(def_fapl, H5D_ACS_PREEMPT_READ_CHUNKS_NAME, &def_chunk_info.w0) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET,FAIL, "can't get preempt read chunks");
+        if(H5P_set(new_plist, H5D_ACS_PREEMPT_READ_CHUNKS_NAME, &def_chunk_info.w0) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set preempt read chunks")
+
+        /* Set the append flush property to its default value */
+        if(H5P_set(new_plist, H5D_ACS_APPEND_FLUSH_NAME, &def_append_flush_info) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set append flush property")
+    }/* end if-else */
 
     /* Set the VDS view & printf gap options */
     if(H5P_set(new_plist, H5D_ACS_VDS_VIEW_NAME, &(dset->shared->layout.storage.u.virt.view)) < 0)
diff --git a/src/H5Dpkg.h b/src/H5Dpkg.h
index 723acf9..02121e6 100644
--- a/src/H5Dpkg.h
+++ b/src/H5Dpkg.h
@@ -443,6 +443,7 @@ struct H5D_shared_t {
     H5T_t              *type;           /* Datatype for this dataset     */
     H5S_t              *space;          /* Dataspace of this dataset    */
     hid_t               dcpl_id;        /* Dataset creation property id */
+    hid_t               dapl_id;        /* Dataset access property id */
     H5D_dcpl_cache_t    dcpl_cache;     /* Cached DCPL values */
     H5O_layout_t        layout;         /* Data layout                  */
     hbool_t             checked_filters;/* TRUE if dataset passes can_apply check */
@@ -523,6 +524,7 @@ typedef struct {
     void *fl_tbuf;                  /* Ptr to the temporary buffer we are using for fixed-length data */
     void *vl_tbuf;                  /* Ptr to the temporary buffer we are using for VL data */
     hsize_t size;                   /* Accumulated number of bytes for the selection */
+    hid_t dxpl_id;                  /* Dataset transfer property list to pass to dataset read */
 } H5D_vlen_bufsize_t;
 
 
diff --git a/src/H5FD.c b/src/H5FD.c
index 61969b6..1a4ab4d 100644
--- a/src/H5FD.c
+++ b/src/H5FD.c
@@ -241,7 +241,7 @@ H5FDregister(const H5FD_class_t *cls)
         HGOTO_ERROR(H5E_ARGS, H5E_UNINITIALIZED, H5I_INVALID_HID, "'get_eof' method is not defined")
     if(!cls->read || !cls->write)
         HGOTO_ERROR(H5E_ARGS, H5E_UNINITIALIZED, H5I_INVALID_HID, "'read' and/or 'write' method is not defined")
-    for (type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t,type))
+    for (type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; type++)
         if(cls->fl_map[type] < H5FD_MEM_NOLIST || cls->fl_map[type] >= H5FD_MEM_NTYPES)
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "invalid free-list mapping")
 
@@ -286,7 +286,7 @@ H5FD_register(const void *_cls, size_t size, hbool_t app_ref)
     HDassert(cls->get_eoa && cls->set_eoa);
     HDassert(cls->get_eof);
     HDassert(cls->read && cls->write);
-    for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
+    for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; type++) {
         HDassert(cls->fl_map[type] >= H5FD_MEM_NOLIST && cls->fl_map[type] < H5FD_MEM_NTYPES);
     }
 
diff --git a/src/H5FDhdfs.c b/src/H5FDhdfs.c
index 0b954cf..819d200 100644
--- a/src/H5FDhdfs.c
+++ b/src/H5FDhdfs.c
@@ -581,6 +581,7 @@ hid_t
 H5FD_hdfs_init(void)
 {
     hid_t ret_value = H5I_INVALID_HID; /* Return value */
+    unsigned int bin_i;
 
     FUNC_ENTER_NOAPI(FAIL)
 
diff --git a/src/H5FDlog.c b/src/H5FDlog.c
index 1c7d549..ac5667f 100644
--- a/src/H5FDlog.c
+++ b/src/H5FDlog.c
@@ -489,8 +489,8 @@ H5FD_log_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr)
 #endif
 #ifdef H5_HAVE_GETTIMEOFDAY
     struct timeval timeval_start;
-    struct timeval open_timeval_diff = {0, 0};
-    struct timeval stat_timeval_diff = {0, 0};
+    struct timeval open_timeval_diff;
+    struct timeval stat_timeval_diff;
 #endif /* H5_HAVE_GETTIMEOFDAY */
     h5_stat_t       sb;
     H5FD_t          *ret_value = NULL;  /* Return value */
diff --git a/src/H5FSsection.c b/src/H5FSsection.c
index cf4a587..df67bd9 100644
--- a/src/H5FSsection.c
+++ b/src/H5FSsection.c
@@ -371,10 +371,10 @@ HDfprintf(stderr, "%s: fspace->alloc_sect_size = %Hu, fspace->sect_size = %Hu\n"
     /* Check if section info lock count dropped to zero */
     if(fspace->sinfo_lock_count == 0) {
         hbool_t release_sinfo_space = FALSE;    /* Flag to indicate section info space in file should be released */
-        hbool_t closing_or_flushing = f->shared->closing;      /* Is closing or flushing in progress */
+        hbool_t flush_in_progress = FALSE;      /* Is flushing in progress */
 
-        /* Check whether cache-flush is in progress if closing is not. */
-        if(!closing_or_flushing && H5AC_get_cache_flush_in_progress(f->shared->cache, &closing_or_flushing) < 0)
+        /* Check whether cache is flush_in_progress */
+        if(H5AC_get_cache_flush_in_progress(f->shared->cache, &flush_in_progress) < 0)
             HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Can't get flush_in_progress")
 
         /* Check if we actually protected the section info */
@@ -390,7 +390,7 @@ HDfprintf(stderr, "%s: fspace->alloc_sect_size = %Hu, fspace->sect_size = %Hu\n"
                 cache_flags |= H5AC__DIRTIED_FLAG;
 
                 /* On file close or flushing, does not allow section info to shrink in size */
-                if(closing_or_flushing) {
+                if(f->shared->closing || flush_in_progress) {
                     if(fspace->sect_size > fspace->alloc_sect_size)
                         cache_flags |= H5AC__DELETED_FLAG | H5AC__TAKE_OWNERSHIP_FLAG;
                     else
@@ -441,7 +441,7 @@ HDfprintf(stderr, "%s: Relinquishing section info ownership\n", FUNC);
                     /* Set flag to release section info space in file */
                     /* On file close or flushing, only need to release section info with size 
                        bigger than previous section */
-                    if(closing_or_flushing) {
+                    if(f->shared->closing || flush_in_progress) {
                         if(fspace->sect_size > fspace->alloc_sect_size)
                             release_sinfo_space = TRUE;
                         else
diff --git a/src/H5Fint.c b/src/H5Fint.c
index 435c1be..153ec2f 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -3654,9 +3654,9 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5F__get_file_id
+ * Function:    H5F_get_file_id
  *
- * Purpose:     The package version of H5Iget_file_id(), obtains the file
+ * Purpose:     The private version of H5Iget_file_id(), obtains the file
  *              ID given an object ID.
  *
  * Return:      Success:    The file ID associated with the object
@@ -3665,22 +3665,31 @@ done:
  *-------------------------------------------------------------------------
  */
 hid_t
-H5F__get_file_id(H5F_t *file, hbool_t app_ref)
+H5F_get_file_id(H5VL_object_t *vol_obj, H5I_type_t obj_type, hbool_t app_ref)
 {
-    hid_t file_id = H5I_INVALID_HID;    /* File ID */
-    hid_t ret_value = H5I_INVALID_HID;  /* Return value */
+    void *vol_obj_file = NULL;                  /* File object pointer */
+    H5VL_loc_params_t loc_params;               /* Location parameters */
+    hid_t           file_id = H5I_INVALID_HID;  /* File ID for object */
+    hid_t           ret_value = H5I_INVALID_HID; /* Return value */
 
-    FUNC_ENTER_PACKAGE
+    FUNC_ENTER_NOAPI(H5I_INVALID_HID)
+
+    /* Set location parameters */
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = obj_type;
+
+    /* Retrieve VOL file from object */
+    if(H5VL_object_get(vol_obj, &loc_params, H5VL_OBJECT_GET_FILE, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &vol_obj_file) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, H5I_INVALID_HID, "can't retrieve file from object")
 
     /* Check if the file's ID already exists */
-    if(H5I_find_id(file, H5I_FILE, &file_id) < 0)
+    if(H5I_find_id(vol_obj_file, H5I_FILE, &file_id) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTGET, H5I_INVALID_HID, "getting file ID failed")
 
     /* If the ID does not exist, register it with the VOL connector */
     if(H5I_INVALID_HID == file_id) {
-        if((file_id = H5VL_wrap_register(H5I_FILE, file, app_ref)) < 0)
+        if((file_id = H5VL_register(H5I_FILE, vol_obj_file, vol_obj->connector, app_ref)) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize file handle")
-        file->id_exists = TRUE;
     } /* end if */
     else {
         /* Increment ref count on existing ID */
@@ -3693,44 +3702,6 @@ H5F__get_file_id(H5F_t *file, hbool_t app_ref)
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F__get_file_id() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5F_get_file_id
- *
- * Purpose:     The private version of H5Iget_file_id(), obtains the file
- *              ID given an object ID.
- *
- * Return:      Success:    The file ID associated with the object
- *              Failure:    H5I_INVALID_HID
- *
- *-------------------------------------------------------------------------
- */
-hid_t
-H5F_get_file_id(hid_t obj_id, H5I_type_t type, hbool_t app_ref)
-{
-    H5VL_object_t  *vol_obj;                    /* File info */
-    hid_t           file_id = H5I_INVALID_HID;  /* File ID for object */
-    hid_t           ret_value = H5I_INVALID_HID; /* Return value */
-
-    FUNC_ENTER_NOAPI(H5I_INVALID_HID)
-
-    /* Get the object pointer */
-    if(NULL == (vol_obj = H5VL_vol_object(obj_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid identifier")
-
-    /* Get the file through the VOL */
-    if(H5VL_file_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_FILE_GET_FILE_ID, (int)type, (int)app_ref, &file_id) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, H5I_INVALID_HID, "unable to get file ID")
-    if(H5I_INVALID_HID == file_id)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, H5I_INVALID_HID, "unable to get the file ID through the VOL")
-
-    /* Set return value */
-    ret_value = file_id;
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5F_get_file_id() */
 
 
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index 7d9a090..6e2c994 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -412,7 +412,6 @@ H5_DLL herr_t H5F__start_swmr_write(H5F_t *f);
 H5_DLL herr_t H5F__close(H5F_t *f);
 H5_DLL herr_t H5F__set_libver_bounds(H5F_t *f, H5F_libver_t low, H5F_libver_t high);
 H5_DLL H5F_t *H5F__get_file(void *obj, H5I_type_t type);
-H5_DLL hid_t H5F__get_file_id(H5F_t *file, hbool_t app_ref);
 H5_DLL herr_t H5F__get_cont_info(const H5F_t *f, H5VL_file_cont_info_t *info);
 
 /* File mount related routines */
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index eaf8093..a96ad83 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -732,7 +732,7 @@ typedef enum H5F_prefix_open_t {
 /* Private functions */
 H5_DLL H5F_t *H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id);
 H5_DLL herr_t H5F_try_close(H5F_t *f, hbool_t *was_closed/*out*/);
-H5_DLL hid_t H5F_get_file_id(hid_t obj_id, H5I_type_t id_type, hbool_t app_ref);
+H5_DLL hid_t H5F_get_file_id(H5VL_object_t *vol_obj, H5I_type_t obj_type, hbool_t app_ref);
 
 /* Functions that retrieve values from the file struct */
 H5_DLL H5F_libver_t H5F_get_low_bound(const H5F_t *f);
diff --git a/src/H5Fsuper.c b/src/H5Fsuper.c
index f8e8f3f..e5d4cde 100644
--- a/src/H5Fsuper.c
+++ b/src/H5Fsuper.c
@@ -1394,7 +1394,7 @@ H5F__super_init(H5F_t *f)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "can't set version of fsinfo")
             f->shared->fs_version = fsinfo.version;
 
-            for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+            for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; ptype++)
                 fsinfo.fs_addr[ptype - 1] = HADDR_UNDEF;
 
             if(H5O_msg_create(&ext_loc, H5O_FSINFO_ID, H5O_MSG_FLAG_DONTSHARE | H5O_MSG_FLAG_MARK_IF_UNKNOWN, H5O_UPDATE_TIME, &fsinfo) < 0)
diff --git a/src/H5Fsuper_cache.c b/src/H5Fsuper_cache.c
index ce216a2..125d6cf 100644
--- a/src/H5Fsuper_cache.c
+++ b/src/H5Fsuper_cache.c
@@ -347,9 +347,9 @@ static herr_t
 H5F__cache_superblock_get_final_load_size(const void *_image, size_t image_len,
     void *_udata, size_t *actual_len)
 {
-    const uint8_t *image = _image; /* Pointer into raw data buffer */
+    const uint8_t *image = (const uint8_t *)_image;   			    /* Pointer into raw data buffer */
     H5F_superblock_cache_ud_t *udata = (H5F_superblock_cache_ud_t *)_udata; /* User data */
-    H5F_super_t sblock; /* Temporary file superblock */
+    H5F_super_t sblock;                 /* Temporary file superblock */
     htri_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_STATIC
@@ -361,15 +361,6 @@ H5F__cache_superblock_get_final_load_size(const void *_image, size_t image_len,
     HDassert(*actual_len == image_len);
     HDassert(image_len >= H5F_SUPERBLOCK_FIXED_SIZE + 6);
 
-    /* Initialize because GCC 5.5 does not realize that
-     * H5F__superblock_prefix_decode() initializes it.
-     *
-     * TBD condition on compiler version.
-     */
-    sblock.super_vers = 0;
-    sblock.sizeof_addr = 0;
-    sblock.sizeof_size = 0;
-
     /* Deserialize the file superblock's prefix */
     if(H5F__superblock_prefix_decode(&sblock, &image, udata, TRUE) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTDECODE, FAIL, "can't decode file superblock prefix")
@@ -402,7 +393,7 @@ done:
 static htri_t
 H5F__cache_superblock_verify_chksum(const void *_image, size_t len, void *_udata)
 {
-    const uint8_t *image = _image;    	/* Pointer into raw data buffer */
+    const uint8_t *image = (const uint8_t *)_image;    	/* Pointer into raw data buffer */
     H5F_superblock_cache_ud_t *udata = (H5F_superblock_cache_ud_t *)_udata; /* User data */
     uint32_t stored_chksum;     /* Stored metadata checksum value */
     uint32_t computed_chksum;   /* Computed metadata checksum value */
@@ -448,7 +439,7 @@ H5F__cache_superblock_deserialize(const void *_image, size_t len, void *_udata,
 {
     H5F_super_t         *sblock = NULL; /* File's superblock */
     H5F_superblock_cache_ud_t *udata = (H5F_superblock_cache_ud_t *)_udata; /* User data */
-    const uint8_t	*image = _image; /* Pointer into raw data buffer */
+    const uint8_t	*image = (const uint8_t *)_image;       /* Pointer into raw data buffer */
     H5F_super_t         *ret_value = NULL;      /* Return value */
 
     FUNC_ENTER_STATIC
@@ -673,7 +664,7 @@ H5F__cache_superblock_serialize(const H5F_t *f, void *_image, size_t H5_ATTR_UNU
     void *_thing)
 {
     H5F_super_t *sblock = (H5F_super_t *)_thing;      /* Pointer to the object */
-    uint8_t *image = _image;         /* Pointer into raw data buffer */
+    uint8_t *image = (uint8_t *)_image;         /* Pointer into raw data buffer */
     haddr_t rel_eof;            /* Relative EOF for file */
     herr_t ret_value = SUCCEED; /* Return value */
 
@@ -879,7 +870,7 @@ static herr_t
 H5F__cache_drvrinfo_get_final_load_size(const void *_image, size_t image_len,
     void *_udata, size_t *actual_len)
 {
-    const uint8_t *image = _image; /* Pointer into raw data buffer */
+    const uint8_t *image = (const uint8_t *)_image;   			/* Pointer into raw data buffer */
     H5F_drvrinfo_cache_ud_t *udata = (H5F_drvrinfo_cache_ud_t *)_udata;	/* User data */
     H5O_drvinfo_t drvrinfo;     /* Driver info */
     herr_t ret_value = SUCCEED; /* Return value */
@@ -893,7 +884,6 @@ H5F__cache_drvrinfo_get_final_load_size(const void *_image, size_t image_len,
     HDassert(*actual_len == image_len);
     HDassert(image_len == H5F_DRVINFOBLOCK_HDR_SIZE);
 
-    drvrinfo.len = 0;
     /* Deserialize the file driver info's prefix */
     if(H5F__drvrinfo_prefix_decode(&drvrinfo, NULL, &image, udata, TRUE) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTDECODE, FAIL, "can't decode file driver info prefix")
@@ -926,7 +916,7 @@ H5F__cache_drvrinfo_deserialize(const void *_image, size_t len, void *_udata,
 {
     H5O_drvinfo_t       *drvinfo = NULL; /* Driver info */
     H5F_drvrinfo_cache_ud_t *udata = (H5F_drvrinfo_cache_ud_t *)_udata;     /* User data */
-    const uint8_t	*image = _image; /* Pointer into raw data buffer */
+    const uint8_t	*image = (const uint8_t *)_image;       /* Pointer into raw data buffer */
     char                drv_name[9];    /* Name of driver */
     H5O_drvinfo_t       *ret_value = NULL;      /* Return value */
 
@@ -1020,7 +1010,7 @@ H5F__cache_drvrinfo_serialize(const H5F_t *f, void *_image, size_t len,
     void *_thing)
 {
     H5O_drvinfo_t *drvinfo = (H5O_drvinfo_t *)_thing;   /* Pointer to the object */
-    uint8_t *image = _image;         /* Pointer into raw data buffer */
+    uint8_t *image = (uint8_t *)_image;         /* Pointer into raw data buffer */
     uint8_t *dbuf;              /* Pointer to beginning of driver info */
     herr_t ret_value = SUCCEED; /* Return value */
 
diff --git a/src/H5HFcache.c b/src/H5HFcache.c
index ab448ef..2d1c1f2 100644
--- a/src/H5HFcache.c
+++ b/src/H5HFcache.c
@@ -406,7 +406,7 @@ static herr_t
 H5HF__cache_hdr_get_final_load_size(const void *_image, size_t image_len,
     void *_udata, size_t *actual_len)
 {
-    H5HF_hdr_t hdr; /* Temporary fractal heap header */
+    H5HF_hdr_t hdr;             /* Temporary fractal heap header */
     const uint8_t *image = (const uint8_t *)_image;       /* Pointer into into supplied image */
     H5HF_hdr_cache_ud_t *udata = (H5HF_hdr_cache_ud_t *)_udata; /* User data for callback */
     herr_t ret_value = SUCCEED; /* Return value */
@@ -419,12 +419,6 @@ H5HF__cache_hdr_get_final_load_size(const void *_image, size_t image_len,
     HDassert(actual_len);
     HDassert(*actual_len == image_len);
 
-    /* Initialize because GCC 5.5 does not realize that the
-     * H5HF__hdr_prefix_decode() call is sufficient to initialize.
-     * GCC 8 is clever enough to see that the variable is initialized.
-     * TBD condition on compiler version.
-     */
-    hdr.filter_len = 0;
     /* Deserialize the fractal heap header's prefix */
     if(H5HF__hdr_prefix_decode(&hdr, &image) < 0)
         HGOTO_ERROR(H5E_HEAP, H5E_CANTDECODE, FAIL, "can't decode fractal heap header prefix")
diff --git a/src/H5HFtiny.c b/src/H5HFtiny.c
index 79d790b..0c27180 100644
--- a/src/H5HFtiny.c
+++ b/src/H5HFtiny.c
@@ -377,7 +377,7 @@ done:
 herr_t
 H5HF_tiny_remove(H5HF_hdr_t *hdr, const uint8_t *id)
 {
-    size_t enc_obj_size = 0;            /* Encoded object size */
+    size_t enc_obj_size;                /* Encoded object size */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
diff --git a/src/H5HGcache.c b/src/H5HGcache.c
index 9f6e73f..29e88df 100644
--- a/src/H5HGcache.c
+++ b/src/H5HGcache.c
@@ -205,7 +205,7 @@ static herr_t
 H5HG__cache_heap_get_final_load_size(const void *image, size_t image_len,
     void *udata, size_t *actual_len)
 {
-    H5HG_heap_t heap; /* Global heap */
+    H5HG_heap_t heap;                   /* Global heap */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_STATIC
@@ -217,12 +217,6 @@ H5HG__cache_heap_get_final_load_size(const void *image, size_t image_len,
     HDassert(*actual_len == image_len);
     HDassert(image_len == H5HG_MINSIZE);
 
-    /* Initialize because GCC 5.5 cannot see that
-     * H5HG__hdr_deserialize() initializes.
-     *
-     * TBD condition on compiler version.
-     */
-    heap.size = 0;
     /* Deserialize the heap's header */
     if(H5HG__hdr_deserialize(&heap, (const uint8_t *)image, (const H5F_t *)udata) < 0)
         HGOTO_ERROR(H5E_HEAP, H5E_CANTDECODE, FAIL, "can't decode global heap prefix")
diff --git a/src/H5I.c b/src/H5I.c
index 76faab1..c3c2d46 100644
--- a/src/H5I.c
+++ b/src/H5I.c
@@ -2270,7 +2270,14 @@ H5Iget_file_id(hid_t obj_id)
 
     /* Call internal function */
     if (H5I_FILE == type || H5I_DATATYPE == type || H5I_GROUP == type || H5I_DATASET == type || H5I_ATTR == type) {
-        if ((ret_value = H5F_get_file_id(obj_id, type, TRUE)) < 0)
+        H5VL_object_t *vol_obj = NULL; /* Object token of obj_id */
+
+        /* Get the VOL object */
+        if(NULL == (vol_obj = H5VL_vol_object(obj_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
+        /* Get the file ID */
+        if ((ret_value = H5F_get_file_id(vol_obj, type, TRUE)) < 0)
             HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, H5I_INVALID_HID, "can't retrieve file ID")
     } /* end if */
     else
diff --git a/src/H5MF.c b/src/H5MF.c
index 14be37a..c100637 100644
--- a/src/H5MF.c
+++ b/src/H5MF.c
@@ -163,7 +163,7 @@ H5MF_init_merge_flags(H5F_shared_t *f_sh)
      *  can merge with the metadata or small 'raw' data aggregator
      */
     all_same = TRUE;
-    for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
+    for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; type++)
         /* Check for any different type mappings */
         if(f_sh->fs_type_map[type] != f_sh->fs_type_map[H5FD_MEM_DEFAULT]) {
             all_same = FALSE;
@@ -187,7 +187,7 @@ H5MF_init_merge_flags(H5F_shared_t *f_sh)
             /* One or more allocation type don't map to the same free list type */
             /* Check if all the metadata allocation types map to the same type */
             all_metadata_same = TRUE;
-            for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
+            for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; type++)
                 /* Skip checking raw data free list mapping */
                 /* (global heap is treated as raw data) */
                 if(type != H5FD_MEM_DRAW && type != H5FD_MEM_GHEAP) {
@@ -1686,7 +1686,7 @@ HDfprintf(stderr, "%s: Entering\n", FUNC);
         /* Iterate over all the free space types that have managers and
          * get each free list's space
          */
-        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype)) {
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; ptype++) {
             /* Test to see if we need to switch rings -- do so if required */
             if(H5MF__fsm_type_is_self_referential(f->shared, ptype))
                 needed_ring = H5AC_RING_MDFSM;
@@ -1708,7 +1708,7 @@ HDfprintf(stderr, "%s: Entering\n", FUNC);
         /* Iterate over all the free space types that have managers and
          * get each free list's space
          */
-        for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
+        for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; type++) {
             /* Test to see if we need to switch rings -- do so if required */
             if(H5MF__fsm_type_is_self_referential(f->shared, (H5F_mem_page_t)type))
                 needed_ring = H5AC_RING_MDFSM;
@@ -1807,9 +1807,9 @@ HDfprintf(stderr, "%s: Entering\n", FUNC);
          *
          * In passing, verify that all the free space managers are closed.
          */
-        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; ptype++)
             fsinfo.fs_addr[ptype - 1] = HADDR_UNDEF;
-        for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
+        for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; type++)
             fsinfo.fs_addr[type-1] = f->shared->fs_addr[type];
         fsinfo.strategy = f->shared->fs_strategy;
         fsinfo.persist = f->shared->fs_persist;
@@ -1824,7 +1824,7 @@ HDfprintf(stderr, "%s: Entering\n", FUNC);
             HGOTO_ERROR(H5E_RESOURCE, H5E_WRITEERROR, FAIL, "error in writing message to superblock extension")
 
         /* Close the free space managers */
-        for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
+        for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; type++) {
             if(f->shared->fs_man[type]) {
                 /* Test to see if we need to switch rings -- do so if required */
                 if(H5MF__fsm_type_is_self_referential(f->shared, (H5F_mem_page_t)type))
@@ -1877,7 +1877,7 @@ HDfprintf(stderr, "%s: Entering\n", FUNC);
         HDassert(H5F_NULL_FSM_ADDR(f) || final_eoa == f->shared->eoa_fsm_fsalloc);
     } /* end if */
     else {  /* super_vers can be 0, 1, 2 */
-        for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
+        for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; type++)
             if(H5MF__close_delete_fstype(f, (H5F_mem_page_t)type) < 0)
                 HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space")
     } /* end else */
@@ -1958,7 +1958,7 @@ HDfprintf(stderr, "%s: Entering\n", FUNC);
     fsinfo.eoa_pre_fsm_fsalloc = HADDR_UNDEF;
     fsinfo.version = f->shared->fs_version;
 
-    for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+    for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; ptype++)
         fsinfo.fs_addr[ptype - 1] = HADDR_UNDEF;
 
     if(f->shared->fs_persist) {
@@ -1980,7 +1980,7 @@ HDfprintf(stderr, "%s: Entering\n", FUNC);
          * file space for the self referential free space managers.  Other
          * data was gathered above.
          */
-        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; ptype++)
             fsinfo.fs_addr[ptype-1] = f->shared->fs_addr[ptype];
         fsinfo.eoa_pre_fsm_fsalloc = f->shared->eoa_fsm_fsalloc;
 
@@ -1990,7 +1990,7 @@ HDfprintf(stderr, "%s: Entering\n", FUNC);
 
         /* Close the free space managers */
         /* use H5MF__close_fstype() for this? */
-        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype)) {
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; ptype++) {
             if(f->shared->fs_man[ptype]) {
                 /* Test to see if we need to switch rings -- do so if required */
                 if(H5MF__fsm_type_is_self_referential(f->shared, ptype))
@@ -2052,7 +2052,7 @@ HDfprintf(stderr, "%s: Entering\n", FUNC);
         /* Iterate over all the free space types that have managers 
          * and get each free list's space 
          */
-        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; ptype++)
             if(H5MF__close_delete_fstype(f, ptype) < 0)
                 HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't close the free space manager")
 
@@ -2125,7 +2125,7 @@ H5MF__close_shrink_eoa(H5F_t *f)
 
         if(H5F_PAGED_AGGR(f)) {
             /* Check the last section of each free-space manager */
-            for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype)) {
+            for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; ptype++) {
                 if(f->shared->fs_man[ptype]) {
                     /* Test to see if we need to switch rings -- do so if required */
                     if(H5MF__fsm_type_is_self_referential(f->shared, ptype))
@@ -2149,7 +2149,7 @@ H5MF__close_shrink_eoa(H5F_t *f)
         } /* end if */
         else {
             /* Check the last section of each free-space manager */
-            for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
+            for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; type++) {
                 if(f->shared->fs_man[type]) {
                     /* Test to see if we need to switch rings -- do so if required */
                     if(H5MF__fsm_type_is_self_referential(f->shared, (H5F_mem_page_t)type))
@@ -2245,7 +2245,7 @@ H5MF_get_freespace(H5F_t *f, hsize_t *tot_space, hsize_t *meta_size)
         end_type = (H5F_mem_page_t)H5FD_MEM_NTYPES;
     } /* end else */
 
-    for(tt = H5FD_MEM_SUPER; tt < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, tt))
+    for(tt = H5FD_MEM_SUPER; tt < H5FD_MEM_NTYPES; tt++)
         if(HADDR_UNDEF == (fs_eoa[tt] = H5F_get_eoa(f, tt)))
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "driver get_eoa request failed")
 
@@ -2260,7 +2260,7 @@ H5MF_get_freespace(H5F_t *f, hsize_t *tot_space, hsize_t *meta_size)
     } /* end if */
 
     /* Iterate over all the free space types that have managers and get each free list's space */
-    for(type = start_type; type < end_type; H5_INC_ENUM(H5F_mem_page_t, type)) {
+    for(type = start_type; type < end_type; type++) {
         fs_started[type] = FALSE;
 
         /* Check if the free space for the file has been initialized */
@@ -2300,7 +2300,7 @@ H5MF_get_freespace(H5F_t *f, hsize_t *tot_space, hsize_t *meta_size)
     } /* end for */
 
     /* Close the free-space managers if they were opened earlier in this routine */
-    for(type = start_type; type < end_type; H5_INC_ENUM(H5F_mem_page_t, type)) {
+    for(type = start_type; type < end_type; type++) {
         /* Test to see if we need to switch rings -- do so if required */
         if(H5MF__fsm_type_is_self_referential(f->shared, (H5F_mem_page_t)type))
             needed_ring = H5AC_RING_MDFSM;
@@ -2387,7 +2387,7 @@ H5MF_get_free_sections(H5F_t *f, H5FD_mem_t type, size_t nsects, H5F_sect_info_t
         if(H5F_PAGED_AGGR(f)) /* set to the corresponding LARGE free-space manager */
             end_type = (H5F_mem_page_t)(end_type + H5FD_MEM_NTYPES);
         else
-            H5_INC_ENUM(H5F_mem_page_t, end_type);
+            end_type++;
     } /* end else */
 
     /* Set up user data for section iteration */
@@ -2403,7 +2403,7 @@ H5MF_get_free_sections(H5F_t *f, H5FD_mem_t type, size_t nsects, H5F_sect_info_t
     curr_ring = H5AC_RING_RDFSM;
 
     /* Iterate over memory types, retrieving the number of sections of each type */
-    for(ty = start_type; ty < end_type; H5_INC_ENUM(H5F_mem_page_t, ty)) {
+    for(ty = start_type; ty < end_type; ty++) {
         hbool_t fs_started = FALSE;	/* The free-space manager is opened or not */
         size_t nums = 0;		/* The number of free-space sections */
 
@@ -2733,7 +2733,7 @@ H5MF_settle_raw_data_fsm(H5F_t *f, hbool_t *fsm_settled)
             else /* no need for a second pass */
                 break;
 
-            for(mem_type = H5FD_MEM_SUPER; mem_type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5F_mem_t, mem_type)) {
+            for(mem_type = H5FD_MEM_SUPER; mem_type < H5FD_MEM_NTYPES; mem_type++) {
                 H5MF__alloc_to_fs_type(f->shared, mem_type, alloc_size, &fsm_type);
 
                 if(pass_count == 0) { /* this is the first pass */
@@ -2834,7 +2834,7 @@ H5MF_settle_raw_data_fsm(H5F_t *f, hbool_t *fsm_settled)
          * those addresses are unknown.  This is OK -- we will write the correct
          * values to the message at free space manager shutdown.
          */
-        for(fsm_type = H5F_MEM_PAGE_SUPER; fsm_type < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, fsm_type))
+        for(fsm_type = H5F_MEM_PAGE_SUPER; fsm_type < H5F_MEM_PAGE_NTYPES; fsm_type++)
             fsinfo.fs_addr[fsm_type - 1] = HADDR_UNDEF;
         fsinfo.strategy = f->shared->fs_strategy;
         fsinfo.persist = f->shared->fs_persist;
@@ -2867,7 +2867,7 @@ H5MF_settle_raw_data_fsm(H5F_t *f, hbool_t *fsm_settled)
          */
 
         /* Reinitialize fsm_visited */
-        for(fsm_type = H5F_MEM_PAGE_SUPER; fsm_type < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, fsm_type))
+        for(fsm_type = H5F_MEM_PAGE_SUPER; fsm_type < H5F_MEM_PAGE_NTYPES; fsm_type++)
             fsm_visited[fsm_type] = FALSE;
 
         for(pass_count = 0; pass_count <= 1; pass_count++) {
@@ -2878,7 +2878,7 @@ H5MF_settle_raw_data_fsm(H5F_t *f, hbool_t *fsm_settled)
             else /* no need for a second pass */
                 break;
 
-            for(mem_type = H5FD_MEM_SUPER; mem_type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5F_mem_t, mem_type)) {
+            for(mem_type = H5FD_MEM_SUPER; mem_type < H5FD_MEM_NTYPES; mem_type++) {
                 H5MF__alloc_to_fs_type(f->shared, mem_type, alloc_size, &fsm_type);
 
                 if(pass_count == 0) { /* this is the first pass */
@@ -2975,7 +2975,7 @@ H5MF_settle_raw_data_fsm(H5F_t *f, hbool_t *fsm_settled)
         } /* end for */
 
         /* verify that all opened FSMs were closed */
-        for(fsm_type = H5F_MEM_PAGE_SUPER; fsm_type < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, fsm_type))
+        for(fsm_type = H5F_MEM_PAGE_SUPER; fsm_type < H5F_MEM_PAGE_NTYPES; fsm_type++)
             HDassert(!fsm_opened[fsm_type]);
 
         /* Indicate that the FSM was settled successfully */
diff --git a/src/H5MFdbg.c b/src/H5MFdbg.c
index e11476b..7bb77e8 100644
--- a/src/H5MFdbg.c
+++ b/src/H5MFdbg.c
@@ -169,7 +169,7 @@ H5MF_sects_debug(H5F_t *f, haddr_t fs_addr, FILE *stream, int indent, int fwidth
     HDassert(indent >= 0);
     HDassert(fwidth >= 0);
 
-    for(type = H5F_MEM_PAGE_DEFAULT; type < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, type))
+    for(type = H5F_MEM_PAGE_DEFAULT; type < H5F_MEM_PAGE_NTYPES; type++)
         if(H5F_addr_eq(f->shared->fs_addr[type], fs_addr)) {
             if(!f->shared->fs_man[type])
                 if(H5MF__open_fstype(f, type) < 0)
@@ -243,7 +243,7 @@ HDfprintf(stderr, "%s: for type = H5FD_MEM_DEFAULT, eoa = %a\n", FUNC, eoa);
     if(H5F_PAGED_AGGR(f)) { /* File space paging */
         H5F_mem_page_t ptype;		/* Memory type for iteration -- page fs */
 
-        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype)) {
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; ptype++) {
             /* Print header for type */
             HDfprintf(stream, "%*sFile Free Space Info for type = %u:\n", indent, "", (unsigned)ptype);
 
@@ -289,7 +289,7 @@ HDfprintf(stderr, "%s: sda_addr = %a, sda_size = %Hu, end of sda = %a\n", FUNC,
 #endif /* H5MF_ALLOC_DEBUG */
 
         /* Iterate over all the free space types that have managers and dump each free list's space */
-        for(atype = H5FD_MEM_DEFAULT; atype < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, atype)) {
+        for(atype = H5FD_MEM_DEFAULT; atype < H5FD_MEM_NTYPES; atype++) {
             /* Print header for type */
             HDfprintf(stream, "%*sFile Free Space Info for type = %u:\n", indent, "", (unsigned)atype);
 
diff --git a/src/H5Mpublic.h b/src/H5Mpublic.h
index 9cbdb32..524ab0f 100644
--- a/src/H5Mpublic.h
+++ b/src/H5Mpublic.h
@@ -40,7 +40,8 @@
 #define H5VL_MAP_PUT            5
 #define H5VL_MAP_GET            6
 #define H5VL_MAP_SPECIFIC       7
-#define H5VL_MAP_CLOSE          8
+#define H5VL_MAP_OPTIONAL       8
+#define H5VL_MAP_CLOSE          9
 
 
 /*******************/
diff --git a/src/H5O.c b/src/H5O.c
index b79914c..3938413 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -278,7 +278,7 @@ H5Oopen_by_addr(hid_t loc_id, haddr_t addr)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
 
     /* Get the file for the object */
-    if((file_id = H5F_get_file_id(loc_id, vol_obj_type, FALSE)) < 0)
+    if((file_id = H5F_get_file_id(vol_obj, vol_obj_type, FALSE)) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a file or file object")
 
     /* Retrieve VOL object */
@@ -290,11 +290,11 @@ H5Oopen_by_addr(hid_t loc_id, haddr_t addr)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid VOL object")
 
     /* This is a native specific routine that requires serialization of the token */
-    p = obj_token;
+    p = (uint8_t *)&obj_token;
     H5F_addr_encode(f, &p, addr);
 
     loc_params.type = H5VL_OBJECT_BY_TOKEN;
-    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.loc_data.loc_by_token.token = &obj_token;
     loc_params.obj_type = vol_obj_type;
 
     /* Open the object */
diff --git a/src/H5Ocopy_ref.c b/src/H5Ocopy_ref.c
index d8efeb5..b835f8e 100644
--- a/src/H5Ocopy_ref.c
+++ b/src/H5Ocopy_ref.c
@@ -24,7 +24,6 @@
 /****************/
 
 #include "H5Omodule.h"          /* This source code file is part of the H5O module */
-#define H5F_FRIEND              /* Suppress error about including H5Fpkg   */
 #define H5R_FRIEND              /* Suppress error about including H5Rpkg   */
 
 
@@ -32,7 +31,7 @@
 /* Headers */
 /***********/
 #include "H5private.h"          /* Generic Functions                        */
-#include "H5Fpkg.h"             /* File                                     */
+#include "H5Fprivate.h"         /* File                                     */
 #include "H5Iprivate.h"         /* IDs                                      */
 #include "H5Lprivate.h"         /* Links                                    */
 #include "H5MMprivate.h"        /* Memory management                        */
@@ -186,7 +185,7 @@ H5O__copy_expand_ref_object1(H5O_loc_t *src_oloc, const void *buf_src,
         /* Set up for the object copy for the reference */
         if(H5R__decode_token_obj_compat(src_buf, &buf_size, &tmp_token, token_size) < 0)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTDECODE, FAIL, "unable to decode src object address")
-        p = tmp_token;
+        p = (uint8_t *)&tmp_token;
         H5F_addr_decode(src_oloc->file, (const uint8_t **)&p, &src_oloc->addr);
         if(!H5F_addr_defined(src_oloc->addr) || src_oloc->addr == 0)
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "undefined reference pointer")
@@ -197,7 +196,7 @@ H5O__copy_expand_ref_object1(H5O_loc_t *src_oloc, const void *buf_src,
             HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, FAIL, "unable to copy object")
 
         /* Set the object reference info for the destination file */
-        p = tmp_token;
+        p = (uint8_t *)&tmp_token;
         H5F_addr_encode(dst_oloc->file, &p, dst_oloc->addr);
         if(H5R__encode_token_obj_compat((const H5VL_token_t *)&tmp_token, token_size, dst_buf, &buf_size) < 0)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTDECODE, FAIL, "unable to encode dst object address")
@@ -359,7 +358,7 @@ H5O__copy_expand_ref_object2(H5O_loc_t *src_oloc, hid_t tid_src, H5T_t *dt_src,
         HGOTO_ERROR(H5E_OHDR, H5E_CANTCONVERT, FAIL, "datatype conversion failed")
 
     /* Retrieve loc ID */
-    if((dst_loc_id = H5F__get_file_id(dst_oloc->file, FALSE)) < 0)
+    if((dst_loc_id = H5F_get_id(dst_oloc->file)) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
 
     /* Making equivalent references in the destination file */
@@ -372,7 +371,7 @@ H5O__copy_expand_ref_object2(H5O_loc_t *src_oloc, hid_t tid_src, H5T_t *dt_src,
         /* Get src object address */
         if(H5R__get_obj_token(ref, &tmp_token, &token_size) < 0)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to get object token")
-        p = tmp_token;
+        p = (uint8_t *)&tmp_token;
         H5F_addr_decode(src_oloc->file, (const uint8_t **)&p, &src_oloc->addr);
 
         /* Attempt to copy object from source to destination file */
@@ -380,7 +379,7 @@ H5O__copy_expand_ref_object2(H5O_loc_t *src_oloc, hid_t tid_src, H5T_t *dt_src,
             HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, FAIL, "unable to copy object")
 
         /* Set dst object address */
-        p = tmp_token;
+        p = (uint8_t *)&tmp_token;
         H5F_addr_encode(dst_oloc->file, &p, dst_oloc->addr);
         if(H5R__set_obj_token(ref, (const H5VL_token_t *)&tmp_token, token_size) < 0)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "unable to set object token")
diff --git a/src/H5Ofsinfo.c b/src/H5Ofsinfo.c
index 25a6754..78e8e19 100644
--- a/src/H5Ofsinfo.c
+++ b/src/H5Ofsinfo.c
@@ -112,7 +112,7 @@ H5O_fsinfo_decode(H5F_t *f, H5O_t H5_ATTR_UNUSED *open_oh,
     if(NULL == (fsinfo = H5FL_CALLOC(H5O_fsinfo_t)))
     HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
 
-    for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+    for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; ptype++)
         fsinfo->fs_addr[ptype - 1] = HADDR_UNDEF;
 
     /* Version of message */
@@ -141,7 +141,7 @@ H5O_fsinfo_decode(H5F_t *f, H5O_t H5_ATTR_UNUSED *open_oh,
                 fsinfo->threshold = threshold;
                 if(HADDR_UNDEF == (fsinfo->eoa_pre_fsm_fsalloc = H5F_get_eoa(f, H5FD_MEM_DEFAULT)) )
                     HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to get file size")
-                for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
+                for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; type++)
                     H5F_addr_decode(f, &p, &(fsinfo->fs_addr[type-1]));
                 break;
 
@@ -181,7 +181,7 @@ H5O_fsinfo_decode(H5F_t *f, H5O_t H5_ATTR_UNUSED *open_oh,
 
         /* Decode addresses of free space managers, if persisting */
         if(fsinfo->persist) {
-            for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+            for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; ptype++)
                 H5F_addr_decode(f, &p, &(fsinfo->fs_addr[ptype - 1]));
         } /* end if */
 
@@ -235,7 +235,7 @@ H5O_fsinfo_encode(H5F_t *f, hbool_t H5_ATTR_UNUSED disable_shared, uint8_t *p, c
     /* Store addresses of free-space managers, if persisting */
     if(fsinfo->persist) {
         /* Addresses of free-space managers */
-        for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+        for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; ptype++)
             H5F_addr_encode(f, &p, fsinfo->fs_addr[ptype - 1]);
     } /* end if */
 
@@ -480,7 +480,7 @@ H5O__fsinfo_debug(H5F_t H5_ATTR_UNUSED *f, const void *_mesg, FILE * stream,
               "eoa_pre_fsm_fsalloc:", fsinfo->eoa_pre_fsm_fsalloc);
 
     if(fsinfo->persist) {
-        for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+        for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; ptype++)
             HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
                 "Free space manager address:", fsinfo->fs_addr[ptype-1]);
     } /* end if */
diff --git a/src/H5Oint.c b/src/H5Oint.c
index 7c922da..d2692a4 100644
--- a/src/H5Oint.c
+++ b/src/H5Oint.c
@@ -31,7 +31,6 @@
 /* Headers */
 /***********/
 #include "H5private.h"          /* Generic Functions                        */
-#include "H5CXprivate.h"        /* API contexts                             */
 #include "H5Eprivate.h"         /* Error handling                           */
 #include "H5Fprivate.h"         /* File access                              */
 #include "H5FLprivate.h"        /* Free lists                               */
diff --git a/src/H5Pdcpl.c b/src/H5Pdcpl.c
index 721ba89..b83e2cf 100644
--- a/src/H5Pdcpl.c
+++ b/src/H5Pdcpl.c
@@ -3324,19 +3324,19 @@ H5P_get_fill_value(H5P_genplist_t *plist, const H5T_t *type, void *value/*out*/)
      */
     if(H5T_get_size(type) >= H5T_get_size(fill.type)) {
         buf = value;
-        if(H5T_path_bkg(tpath) && NULL == (bkg = H5MM_malloc(H5T_get_size(type))))
+        if(H5T_path_bkg(tpath) && NULL == (bkg = H5MM_calloc(H5T_get_size(type))))
             HGOTO_ERROR(H5E_PLIST, H5E_CANTALLOC, FAIL, "memory allocation failed for type conversion")
     } /* end if */
     else {
-        if(NULL == (buf = H5MM_malloc(H5T_get_size(fill.type))))
+        if(NULL == (buf = H5MM_calloc(H5T_get_size(fill.type))))
             HGOTO_ERROR(H5E_PLIST, H5E_CANTALLOC, FAIL, "memory allocation failed for type conversion")
-        if(H5T_path_bkg(tpath) && NULL == (bkg = H5MM_malloc(H5T_get_size(fill.type))))
+        if(H5T_path_bkg(tpath) && NULL == (bkg = H5MM_calloc(H5T_get_size(fill.type))))
             HGOTO_ERROR(H5E_PLIST, H5E_CANTALLOC, FAIL, "memory allocation failed for type conversion")
     } /* end else */
     H5MM_memcpy(buf, fill.buf, H5T_get_size(fill.type));
 
     /* Do the conversion */
-    if((dst_id = H5I_register(H5I_DATATYPE, H5T_copy(type, H5T_COPY_TRANSIENT), FALSE)) < 0)
+    if((dst_id = H5I_register(H5I_DATATYPE, H5T_copy(type, H5T_COPY_ALL), FALSE)) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINIT, FAIL, "unable to copy/register datatype")
     if(H5T_convert(tpath, src_id, dst_id, (size_t)1, (size_t)0, (size_t)0, buf, bkg) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINIT, FAIL, "datatype conversion failed")
diff --git a/src/H5Pmapl.c b/src/H5Pmapl.c
index 59da91a..fe5be0f 100644
--- a/src/H5Pmapl.c
+++ b/src/H5Pmapl.c
@@ -138,7 +138,6 @@ done:
 } /* end H5P__macc_reg_prop() */
 
 
-#ifdef H5_HAVE_MAP_API
 /*-------------------------------------------------------------------------
  * Function:    H5Pset_map_iterate_hints
  *
@@ -215,4 +214,4 @@ H5Pget_map_iterate_hints(hid_t mapl_id, size_t *key_prefetch_size, size_t *key_a
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Pget_map_iterate_hints() */
-#endif /*  H5_HAVE_MAP_API */
+
diff --git a/src/H5R.c b/src/H5R.c
index 11b75ca..2c4c713 100644
--- a/src/H5R.c
+++ b/src/H5R.c
@@ -74,7 +74,7 @@
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Rcreate_object(hid_t loc_id, const char *name, H5R_ref_t *ref_ptr)
+H5Rcreate_object(hid_t loc_id, const char *name, hid_t oapl_id, H5R_ref_t *ref_ptr)
 {
     H5VL_object_t *vol_obj = NULL;  /* Object token of loc_id */
     H5I_type_t obj_type;            /* Object type of loc_id */
@@ -86,13 +86,22 @@ H5Rcreate_object(hid_t loc_id, const char *name, H5R_ref_t *ref_ptr)
     herr_t ret_value = SUCCEED;     /* Return value */
 
     FUNC_ENTER_API(FAIL)
-    H5TRACE3("e", "i*s*Rr", loc_id, name, ref_ptr);
+    H5TRACE4("e", "i*si*Rr", loc_id, name, oapl_id, ref_ptr);
 
     /* Check args */
     if(ref_ptr == NULL)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")
     if(!name || !*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name given")
+    if(oapl_id < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
+
+    /* Get object access property list */
+    if(H5P_DEFAULT == oapl_id)
+        oapl_id = H5P_LINK_ACCESS_DEFAULT;
+    else
+        if(TRUE != H5P_isa_class(oapl_id, H5P_LINK_ACCESS))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "oapl_id is not a link access property list ID")
 
     /* Get the VOL object */
     if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
@@ -103,7 +112,7 @@ H5Rcreate_object(hid_t loc_id, const char *name, H5R_ref_t *ref_ptr)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Get the file for the object */
-    if((file_id = H5F_get_file_id(loc_id, obj_type, FALSE)) < 0)
+    if((file_id = H5F_get_file_id(vol_obj, obj_type, FALSE)) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
 
     /* Retrieve VOL file object */
@@ -117,10 +126,11 @@ H5Rcreate_object(hid_t loc_id, const char *name, H5R_ref_t *ref_ptr)
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_NAME;
     loc_params.loc_data.loc_by_name.name = name;
+    loc_params.loc_data.loc_by_name.lapl_id = oapl_id;
     loc_params.obj_type = obj_type;
 
     /* Get the object token */
-    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_LOOKUP, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, obj_token) < 0)
+    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_LOOKUP, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &obj_token) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to retrieve object token")
 
     /* Create the reference (do not pass filename, since file_id is attached) */
@@ -152,7 +162,7 @@ done:
  */
 herr_t
 H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id,
-    H5R_ref_t *ref_ptr)
+    hid_t oapl_id, H5R_ref_t *ref_ptr)
 {
     H5VL_object_t *vol_obj = NULL;  /* Object token of loc_id */
     H5I_type_t obj_type;            /* Object type of loc_id */
@@ -165,7 +175,7 @@ H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id,
     herr_t ret_value = SUCCEED;     /* Return value */
 
     FUNC_ENTER_API(FAIL)
-    H5TRACE4("e", "i*si*Rr", loc_id, name, space_id, ref_ptr);
+    H5TRACE5("e", "i*sii*Rr", loc_id, name, space_id, oapl_id, ref_ptr);
 
     /* Check args */
     if(ref_ptr == NULL)
@@ -176,6 +186,15 @@ H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id,
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "reference region dataspace id must be valid")
     if(NULL == (space = (struct H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
+    if(oapl_id < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
+
+    /* Get object access property list */
+    if(H5P_DEFAULT == oapl_id)
+        oapl_id = H5P_LINK_ACCESS_DEFAULT;
+    else
+        if(TRUE != H5P_isa_class(oapl_id, H5P_LINK_ACCESS))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "oapl_id is not a link access property list ID")
 
     /* Get the VOL object */
     if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
@@ -186,7 +205,7 @@ H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Get the file for the object */
-    if((file_id = H5F_get_file_id(loc_id, obj_type, FALSE)) < 0)
+    if((file_id = H5F_get_file_id(vol_obj, obj_type, FALSE)) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
 
     /* Retrieve VOL file object */
@@ -200,10 +219,11 @@ H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id,
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_NAME;
     loc_params.loc_data.loc_by_name.name = name;
+    loc_params.loc_data.loc_by_name.lapl_id = oapl_id;
     loc_params.obj_type = obj_type;
 
     /* Get the object token */
-    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_LOOKUP, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, obj_token) < 0)
+    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_LOOKUP, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &obj_token) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to retrieve object token")
 
     /* Create the reference (do not pass filename, since file_id is attached) */
@@ -234,7 +254,7 @@ done:
  */
 herr_t
 H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name,
-    H5R_ref_t *ref_ptr)
+    hid_t oapl_id, H5R_ref_t *ref_ptr)
 {
     H5VL_object_t *vol_obj = NULL;  /* Object token of loc_id */
     H5I_type_t obj_type;            /* Object type of loc_id */
@@ -246,7 +266,7 @@ H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name,
     herr_t ret_value = SUCCEED;     /* Return value */
 
     FUNC_ENTER_API(FAIL)
-    H5TRACE4("e", "i*s*s*Rr", loc_id, name, attr_name, ref_ptr);
+    H5TRACE5("e", "i*s*si*Rr", loc_id, name, attr_name, oapl_id, ref_ptr);
 
     /* Check args */
     if(ref_ptr == NULL)
@@ -255,6 +275,15 @@ H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name given")
     if(!attr_name || !*attr_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name given")
+    if(oapl_id < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
+
+    /* Get object access property list */
+    if(H5P_DEFAULT == oapl_id)
+        oapl_id = H5P_LINK_ACCESS_DEFAULT;
+    else
+        if(TRUE != H5P_isa_class(oapl_id, H5P_LINK_ACCESS))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "oapl_id is not a link access property list ID")
 
     /* Get the VOL object */
     if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
@@ -265,7 +294,7 @@ H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Get the file for the object */
-    if((file_id = H5F_get_file_id(loc_id, obj_type, FALSE)) < 0)
+    if((file_id = H5F_get_file_id(vol_obj, obj_type, FALSE)) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
 
     /* Retrieve VOL file object */
@@ -279,10 +308,11 @@ H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name,
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_NAME;
     loc_params.loc_data.loc_by_name.name = name;
+    loc_params.loc_data.loc_by_name.lapl_id = oapl_id;
     loc_params.obj_type = obj_type;
 
     /* Get the object token */
-    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_LOOKUP, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, obj_token) < 0)
+    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_LOOKUP, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &obj_token) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to retrieve object token")
 
     /* Create the reference (do not pass filename, since file_id is attached) */
@@ -481,7 +511,7 @@ H5Ropen_object(const H5R_ref_t *ref_ptr, hid_t rapl_id, hid_t oapl_id)
 
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_TOKEN;
-    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.loc_data.loc_by_token.token = &obj_token;
     loc_params.obj_type = H5I_get_type(loc_id);
 
     /* Open object by token */
@@ -553,7 +583,7 @@ H5Ropen_region(const H5R_ref_t *ref_ptr, hid_t rapl_id, hid_t oapl_id)
 
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_TOKEN;
-    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.loc_data.loc_by_token.token = &obj_token;
     loc_params.obj_type = H5I_get_type(loc_id);
 
     /* Open object by token */
@@ -645,7 +675,7 @@ H5Ropen_attr(const H5R_ref_t *ref_ptr, hid_t rapl_id, hid_t aapl_id)
 
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_TOKEN;
-    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.loc_data.loc_by_token.token = &obj_token;
     loc_params.obj_type = H5I_get_type(loc_id);
 
     /* Open object by token */
@@ -735,7 +765,7 @@ H5Rget_obj_type3(const H5R_ref_t *ref_ptr, hid_t rapl_id, H5O_type_t *obj_type)
 
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_TOKEN;
-    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.loc_data.loc_by_token.token = &obj_token;
     loc_params.obj_type = H5I_get_type(loc_id);
 
     /* Retrieve object's type */
@@ -843,7 +873,7 @@ H5Rget_obj_name(const H5R_ref_t *ref_ptr, hid_t rapl_id, char *buf, size_t size)
 
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_TOKEN;
-    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.loc_data.loc_by_token.token = &obj_token;
     loc_params.obj_type = H5I_get_type(loc_id);
 
     /* Retrieve object's name */
diff --git a/src/H5Rdeprec.c b/src/H5Rdeprec.c
index b9bdffa..ad3c219 100644
--- a/src/H5Rdeprec.c
+++ b/src/H5Rdeprec.c
@@ -123,12 +123,12 @@ H5Rget_obj_type1(hid_t id, H5R_type_t ref_type, const void *ref)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "invalid location identifier")
 
     /* Get object token */
-    if(H5R__decode_token_compat(id, vol_obj_type, ref_type, buf, &obj_token) < 0)
+    if(H5R__decode_token_compat(vol_obj, vol_obj_type, ref_type, buf, &obj_token) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, H5G_UNKNOWN, "unable to get object token")
 
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_TOKEN;
-    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.loc_data.loc_by_token.token = &obj_token;
     loc_params.obj_type = vol_obj_type;
 
     /* Retrieve object's type */
@@ -183,12 +183,12 @@ H5Rdereference1(hid_t obj_id, H5R_type_t ref_type, const void *ref)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
 
     /* Get object token */
-    if(H5R__decode_token_compat(obj_id, vol_obj_type, ref_type, buf, &obj_token) < 0)
+    if(H5R__decode_token_compat(vol_obj, vol_obj_type, ref_type, buf, &obj_token) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, H5I_INVALID_HID, "unable to get object token")
 
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_TOKEN;
-    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.loc_data.loc_by_token.token = &obj_token;
     loc_params.obj_type = vol_obj_type;
 
     /* Dereference */
@@ -258,14 +258,15 @@ H5Rcreate(void *ref, hid_t loc_id, const char *name, H5R_type_t ref_type,
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_NAME;
     loc_params.loc_data.loc_by_name.name = name;
+    loc_params.loc_data.loc_by_name.lapl_id = H5P_LINK_ACCESS_DEFAULT;
     loc_params.obj_type = vol_obj_type;
 
     /* Get the object token */
-    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_LOOKUP, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, obj_token) < 0)
+    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_LOOKUP, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &obj_token) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "unable to retrieve object token")
 
     /* Get the file for the object */
-    if((file_id = H5F_get_file_id(loc_id, vol_obj_type, FALSE)) < 0)
+    if((file_id = H5F_get_file_id(vol_obj, vol_obj_type, FALSE)) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
 
     /* Retrieve VOL object */
@@ -351,12 +352,12 @@ H5Rget_obj_type2(hid_t id, H5R_type_t ref_type, const void *ref,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Get object token */
-    if(H5R__decode_token_compat(id, vol_obj_type, ref_type, buf, &obj_token) < 0)
+    if(H5R__decode_token_compat(vol_obj, vol_obj_type, ref_type, buf, &obj_token) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, FAIL, "unable to get object token")
 
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_TOKEN;
-    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.loc_data.loc_by_token.token = &obj_token;
     loc_params.obj_type = vol_obj_type;
 
     /* Retrieve object's type */
@@ -415,12 +416,12 @@ H5Rdereference2(hid_t obj_id, hid_t oapl_id, H5R_type_t ref_type,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
 
     /* Get object token */
-    if(H5R__decode_token_compat(obj_id, vol_obj_type, ref_type, buf, &obj_token) < 0)
+    if(H5R__decode_token_compat(vol_obj, vol_obj_type, ref_type, buf, &obj_token) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, H5I_INVALID_HID, "unable to get object token")
 
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_TOKEN;
-    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.loc_data.loc_by_token.token = &obj_token;
     loc_params.obj_type = vol_obj_type;
 
     /* Open object by token */
@@ -479,7 +480,7 @@ H5Rget_region(hid_t id, H5R_type_t ref_type, const void *ref)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
 
     /* Get the file for the object */
-    if((file_id = H5F_get_file_id(id, vol_obj_type, FALSE)) < 0)
+    if((file_id = H5F_get_file_id(vol_obj, vol_obj_type, FALSE)) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a file or file object")
 
     /* Retrieve VOL object */
@@ -548,12 +549,12 @@ H5Rget_name(hid_t id, H5R_type_t ref_type, const void *ref, char *name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "invalid location identifier")
 
     /* Get object token */
-    if(H5R__decode_token_compat(id, vol_obj_type, ref_type, buf, &obj_token) < 0)
+    if(H5R__decode_token_compat(vol_obj, vol_obj_type, ref_type, buf, &obj_token) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, (-1), "unable to get object token")
 
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_TOKEN;
-    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.loc_data.loc_by_token.token = &obj_token;
     loc_params.obj_type = vol_obj_type;
 
     /* Retrieve object's name */
diff --git a/src/H5Rint.c b/src/H5Rint.c
index c015715..ce6574d 100644
--- a/src/H5Rint.c
+++ b/src/H5Rint.c
@@ -258,7 +258,7 @@ H5R__create_object(const H5VL_token_t *obj_token, size_t token_size,
     HDassert(ref);
 
     /* Create new reference */
-    H5MM_memcpy(ref->ref.obj.token, obj_token, token_size);
+    H5MM_memcpy(&ref->ref.obj.token, obj_token, token_size);
     ref->ref.obj.filename = NULL;
     ref->loc_id = H5I_INVALID_HID;
     ref->type = (uint8_t)H5R_OBJECT2;
@@ -300,7 +300,7 @@ H5R__create_region(const H5VL_token_t *obj_token, size_t token_size,
     HDassert(ref);
 
     /* Create new reference */
-    H5MM_memcpy(ref->ref.obj.token, obj_token, token_size);
+    H5MM_memcpy(&ref->ref.obj.token, obj_token, token_size);
     ref->ref.obj.filename = NULL;
     if(NULL == (ref->ref.reg.space = H5S_copy(space, FALSE, TRUE)))
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCOPY, FAIL, "unable to copy dataspace")
@@ -355,7 +355,7 @@ H5R__create_attr(const H5VL_token_t *obj_token, size_t token_size,
         HGOTO_ERROR(H5E_REFERENCE, H5E_ARGS, FAIL, "attribute name too long (%d > %d)", (int)HDstrlen(attr_name), H5R_MAX_STRING_LEN)
 
     /* Create new reference */
-    H5MM_memcpy(ref->ref.obj.token, obj_token, token_size);
+    H5MM_memcpy(&ref->ref.obj.token, obj_token, token_size);
     ref->ref.obj.filename = NULL;
     if(NULL == (ref->ref.attr.name = HDstrdup(attr_name)))
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCOPY, FAIL, "Cannot copy attribute name")
@@ -413,6 +413,7 @@ H5R__destroy(H5R_ref_priv_t *ref)
             break;
         case H5R_OBJECT1:
         case H5R_DATASET_REGION1:
+            break;
         case H5R_BADTYPE:
         case H5R_MAXTYPE:
             HDassert("invalid reference type" && 0);
@@ -423,7 +424,7 @@ H5R__destroy(H5R_ref_priv_t *ref)
     } /* end switch */
 
     /* Decrement refcount of attached loc_id */
-    if((ref->loc_id != H5I_INVALID_HID) && (H5I_dec_ref(ref->loc_id) < 0))
+    if(ref->type && (ref->loc_id != H5I_INVALID_HID) && (H5I_dec_ref(ref->loc_id) < 0))
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDEC, FAIL, "decrementing location ID failed")
 
 done:
@@ -601,7 +602,7 @@ H5R__equal(const H5R_ref_priv_t *ref1, const H5R_ref_priv_t *ref2)
     /* Compare object addresses */
     if(ref1->token_size != ref2->token_size)
         HGOTO_DONE(FALSE);
-    if(0 != HDmemcmp(ref1->ref.obj.token, ref2->ref.obj.token, ref1->token_size))
+    if(0 != HDmemcmp(&ref1->ref.obj.token, &ref2->ref.obj.token, ref1->token_size))
         HGOTO_DONE(FALSE);
 
     /* Compare filenames */
@@ -658,7 +659,7 @@ H5R__copy(const H5R_ref_priv_t *src_ref, H5R_ref_priv_t *dst_ref)
 
     HDassert((src_ref != NULL) && (dst_ref != NULL));
 
-    H5MM_memcpy(dst_ref->ref.obj.token, src_ref->ref.obj.token, src_ref->token_size);
+    H5MM_memcpy(&dst_ref->ref.obj.token, &src_ref->ref.obj.token, src_ref->token_size);
     dst_ref->encode_size = src_ref->encode_size;
     dst_ref->type = src_ref->type;
     dst_ref->token_size = src_ref->token_size;
@@ -728,7 +729,7 @@ H5R__get_obj_token(const H5R_ref_priv_t *ref, H5VL_token_t *obj_token,
     if(obj_token) {
         if(0 == ref->token_size)
             HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCOPY, FAIL, "NULL token size")
-        H5MM_memcpy(obj_token, ref->ref.obj.token, ref->token_size);
+        H5MM_memcpy(obj_token, &ref->ref.obj.token, ref->token_size);
     }
     if(token_size)
         *token_size = ref->token_size;
@@ -760,7 +761,7 @@ H5R__set_obj_token(H5R_ref_priv_t *ref, const H5VL_token_t *obj_token,
     HDassert(token_size);
     HDassert(token_size <= H5VL_MAX_TOKEN_SIZE);
 
-    H5MM_memcpy(ref->ref.obj.token, obj_token, ref->token_size);
+    H5MM_memcpy(&ref->ref.obj.token, obj_token, ref->token_size);
     ref->token_size = token_size;
 
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1169,8 +1170,8 @@ H5R__encode_region(H5S_t *space, unsigned char *buf, size_t *nalloc)
 
     /* Don't encode if buffer size isn't big enough or buffer is empty */
     if(buf && *nalloc >= ((size_t)buf_size + 2 * H5_SIZEOF_UINT32_T)) {
-        int rank;
         p = (uint8_t *)buf;
+        int rank;
 
         /* Encode the size for safety check */
         UINT32ENCODE(p, (uint32_t)buf_size);
@@ -1479,18 +1480,18 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5R__decode_token_compat(hid_t id, H5I_type_t type, H5R_type_t ref_type,
+H5R__decode_token_compat(H5VL_object_t *vol_obj, H5I_type_t type, H5R_type_t ref_type,
     const unsigned char *buf, H5VL_token_t *obj_token)
 {
     hid_t file_id = H5I_INVALID_HID;    /* File ID for region reference */
-    void *vol_obj_file = NULL;
+    H5VL_object_t *vol_obj_file = NULL;
     H5VL_file_cont_info_t cont_info = {H5VL_CONTAINER_INFO_VERSION, 0, 0, 0};
     herr_t ret_value = SUCCEED;
 
     FUNC_ENTER_PACKAGE
 
     /* Get the file for the object */
-    if((file_id = H5F_get_file_id(id, type, FALSE)) < 0)
+    if((file_id = H5F_get_file_id(vol_obj, type, FALSE)) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
 
     /* Retrieve VOL object */
@@ -1701,13 +1702,13 @@ H5R__decode_token_region_compat(H5F_t *f, const unsigned char *buf,
 
     /* Get object address */
     p = (const uint8_t *)data;
-    H5MM_memcpy(token, p, token_size);
+    H5MM_memcpy(&token, p, token_size);
     p += token_size;
 
     if(space_ptr) {
         H5O_loc_t oloc; /* Object location */
         H5S_t *space = NULL;
-        const uint8_t *q = token;
+        const uint8_t *q = (const uint8_t *)&token;
 
         /* Initialize the object location */
         H5O_loc_reset(&oloc);
@@ -1725,7 +1726,7 @@ H5R__decode_token_region_compat(H5F_t *f, const unsigned char *buf,
         *space_ptr = space;
     }
     if(obj_token)
-        H5MM_memcpy(obj_token, token, token_size);
+        H5MM_memcpy(obj_token, &token, token_size);
 
 done:
     H5MM_free(data);
diff --git a/src/H5Rpkg.h b/src/H5Rpkg.h
index 19f3115..7471487 100644
--- a/src/H5Rpkg.h
+++ b/src/H5Rpkg.h
@@ -118,7 +118,7 @@ H5_DLL herr_t   H5R__encode_heap(H5F_t *f, unsigned char *buf, size_t *nalloc, c
 H5_DLL herr_t   H5R__decode_heap(H5F_t *f, const unsigned char *buf, size_t *nbytes, unsigned char **data_ptr, size_t *data_size);
 H5_DLL herr_t   H5R__free_heap(H5F_t *f, const unsigned char *buf, size_t nbytes);
 
-H5_DLL herr_t   H5R__decode_token_compat(hid_t id, H5I_type_t type, H5R_type_t ref_type, const unsigned char *buf, H5VL_token_t *obj_token);
+H5_DLL herr_t   H5R__decode_token_compat(H5VL_object_t *vol_obj, H5I_type_t type, H5R_type_t ref_type, const unsigned char *buf, H5VL_token_t *obj_token);
 
 H5_DLL herr_t   H5R__encode_token_obj_compat(const H5VL_token_t *obj_token, size_t token_size, unsigned char *buf, size_t *nalloc);
 H5_DLL herr_t   H5R__decode_token_obj_compat(const unsigned char *buf, size_t *nbytes, H5VL_token_t *obj_token, size_t token_size);
diff --git a/src/H5Rpublic.h b/src/H5Rpublic.h
index 045e04a..a13d54b 100644
--- a/src/H5Rpublic.h
+++ b/src/H5Rpublic.h
@@ -71,7 +71,7 @@ typedef haddr_t hobj_ref_t;
  * Note! This type can only be used with the "native" HDF5 VOL connector.
  */
 typedef struct {
-    unsigned char content[H5R_DSET_REG_REF_BUF_SIZE];
+    char __data[H5R_DSET_REG_REF_BUF_SIZE];
 } hdset_reg_ref_t;
 
 /**
@@ -80,7 +80,7 @@ typedef struct {
  * should always be used with the current reference API.
  */
 typedef struct {
-    unsigned char content[H5R_REF_BUF_SIZE];
+    char __data[H5R_REF_BUF_SIZE];
 } H5R_ref_t;
 
 /********************/
@@ -97,9 +97,9 @@ extern "C" {
 #endif
 
 /* Constructors */
-H5_DLL herr_t   H5Rcreate_object(hid_t loc_id, const char *name, H5R_ref_t *ref_ptr);
-H5_DLL herr_t   H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id, H5R_ref_t *ref_ptr);
-H5_DLL herr_t   H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name, H5R_ref_t *ref_ptr);
+H5_DLL herr_t   H5Rcreate_object(hid_t loc_id, const char *name, hid_t oapl_id, H5R_ref_t *ref_ptr);
+H5_DLL herr_t   H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id, hid_t oapl_id, H5R_ref_t *ref_ptr);
+H5_DLL herr_t   H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name, hid_t oapl_id, H5R_ref_t *ref_ptr);
 H5_DLL herr_t   H5Rdestroy(H5R_ref_t *ref_ptr);
 
 /* Info */
diff --git a/src/H5SL.c b/src/H5SL.c
index ec06395..5f00fb8 100644
--- a/src/H5SL.c
+++ b/src/H5SL.c
@@ -1394,7 +1394,7 @@ H5SL_search(H5SL_t *slist, const void *key)
 {
     H5SL_node_t *x;                             /* Current node to examine */
     uint32_t hashval = 0;                       /* Hash value for key */
-    void *ret_value = NULL;                     /* Return value */
+    void *ret_value;                            /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
@@ -1695,7 +1695,7 @@ H5SL_find(H5SL_t *slist, const void *key)
 {
     H5SL_node_t *x;                             /* Current node to examine */
     uint32_t hashval = 0;                       /* Hash value for key */
-    H5SL_node_t *ret_value = NULL;              /* Return value */
+    H5SL_node_t *ret_value;                     /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
diff --git a/src/H5SM.c b/src/H5SM.c
index 91ef98b..290e575 100644
--- a/src/H5SM.c
+++ b/src/H5SM.c
@@ -313,7 +313,7 @@ ssize_t
 H5SM_get_index(const H5SM_master_table_t *table, unsigned type_id)
 {
     size_t x;
-    unsigned type_flag = 0;
+    unsigned type_flag;
     ssize_t ret_value = FAIL;
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -353,7 +353,7 @@ htri_t
 H5SM_type_shared(H5F_t *f, unsigned type_id)
 {
     H5SM_master_table_t *table = NULL;  /* Shared object master table */
-    unsigned type_flag = 0;             /* Flag corresponding to message type */
+    unsigned type_flag;                 /* Flag corresponding to message type */
     size_t u;                           /* Local index variable */
     htri_t ret_value = FALSE;           /* Return value */
 
diff --git a/src/H5Shyper.c b/src/H5Shyper.c
index 4796fb9..dc97ea2 100644
--- a/src/H5Shyper.c
+++ b/src/H5Shyper.c
@@ -4265,6 +4265,9 @@ H5S__hyper_deserialize(H5S_t **space, const uint8_t **p)
     /* Decode version */
     UINT32DECODE(pp, version);
 
+    if(version < H5S_HYPER_VERSION_1 || version > H5S_HYPER_VERSION_LATEST)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_BADVALUE, FAIL, "bad version number for hyperslab selection")
+
     if(version >= (uint32_t)H5S_HYPER_VERSION_2) {
         /* Decode flags */
         flags = *(pp)++;
@@ -11503,7 +11506,7 @@ H5S__hyper_project_intersection(const H5S_t *src_space, const H5S_t *dst_space,
     HDassert(src_intersect_space);
     HDassert(proj_space);
 
-    /* Assert that src_space and src_intersect_space have same extent and there
+    /* Assert that src_space and src_intersect_space have same rank and there
      * are no point selections */
     HDassert(H5S_GET_EXTENT_NDIMS(src_space) == H5S_GET_EXTENT_NDIMS(src_intersect_space));
     HDassert(H5S_GET_SELECT_NPOINTS(src_space) == H5S_GET_SELECT_NPOINTS(dst_space));
diff --git a/src/H5Spkg.h b/src/H5Spkg.h
index ba60cbf..e139bce 100644
--- a/src/H5Spkg.h
+++ b/src/H5Spkg.h
@@ -41,9 +41,10 @@
 #define H5S_SELECT_FLAG_BITS    (H5S_HYPER_REGULAR)
 
 /* Versions for H5S_SEL_HYPER selection info */
-#define H5S_HYPER_VERSION_1     1
-#define H5S_HYPER_VERSION_2     2
-#define H5S_HYPER_VERSION_3     3
+#define H5S_HYPER_VERSION_1         1
+#define H5S_HYPER_VERSION_2         2
+#define H5S_HYPER_VERSION_3         3
+#define H5S_HYPER_VERSION_LATEST    H5S_HYPER_VERSION_3
 
 /* Versions for H5S_SEL_POINTS selection info */
 #define H5S_POINT_VERSION_1     1
diff --git a/src/H5Sselect.c b/src/H5Sselect.c
index bf0441f..6c8b898 100644
--- a/src/H5Sselect.c
+++ b/src/H5Sselect.c
@@ -2599,7 +2599,12 @@ H5S_select_project_intersection(const H5S_t *src_space, const H5S_t *dst_space,
     const H5S_t *src_intersect_space, H5S_t **new_space_ptr,
     hbool_t share_selection)
 {
-    H5S_t *new_space = NULL;           /* New dataspace constructed */
+    H5S_t *new_space = NULL;            /* New dataspace constructed */
+    H5S_t *tmp_src_intersect_space = NULL; /* Temporary SIS converted from points->hyperslabs */
+    H5S_sel_iter_t ss_iter;             /* Selection iterator for src_space */
+    hbool_t ss_iter_init = FALSE;       /* Whether ss_iter has been initialized */
+    H5S_sel_iter_t ds_iter;             /* Selection iterator for dst_space */
+    hbool_t ds_iter_init = FALSE;       /* Whether ds_iter has been initialized */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -2609,6 +2614,8 @@ H5S_select_project_intersection(const H5S_t *src_space, const H5S_t *dst_space,
     HDassert(dst_space);
     HDassert(src_intersect_space);
     HDassert(new_space_ptr);
+    HDassert(H5S_GET_SELECT_NPOINTS(src_space) == H5S_GET_SELECT_NPOINTS(dst_space));
+    HDassert(H5S_GET_EXTENT_NDIMS(src_space) == H5S_GET_EXTENT_NDIMS(src_intersect_space));
 
     /* Create new space, using dst extent.  Start with "all" selection. */
     if(NULL == (new_space = H5S_create(H5S_SIMPLE)))
@@ -2618,7 +2625,7 @@ H5S_select_project_intersection(const H5S_t *src_space, const H5S_t *dst_space,
 
     /* If the intersecting space is "all", the intersection must be equal to the
      * source space and the projection must be equal to the destination space */
-    if(src_intersect_space->select.type->type == H5S_SEL_ALL) {
+    if(H5S_GET_SELECT_TYPE(src_intersect_space) == H5S_SEL_ALL) {
         /* Copy the destination selection. */
         if(H5S_select_copy(new_space, dst_space, FALSE) < 0)
             HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCOPY, FAIL, "can't copy destination space selection")
@@ -2632,20 +2639,136 @@ H5S_select_project_intersection(const H5S_t *src_space, const H5S_t *dst_space,
         if(H5S_select_none(new_space) < 0)
             HGOTO_ERROR(H5E_DATASPACE, H5E_CANTDELETE, FAIL, "can't change selection")
     } /* end if */
-    /* If any of the spaces use point selection, fall back to general algorithm */
-    else if((src_intersect_space->select.type->type == H5S_SEL_POINTS)
-            || (src_space->select.type->type == H5S_SEL_POINTS)
-            || (dst_space->select.type->type == H5S_SEL_POINTS))
-        HGOTO_ERROR(H5E_DATASPACE, H5E_UNSUPPORTED, FAIL, "point selections not currently supported")
     else {
-        HDassert(src_intersect_space->select.type->type == H5S_SEL_HYPERSLABS);
-        HDassert(src_space->select.type->type != H5S_SEL_NONE);
-        HDassert(dst_space->select.type->type != H5S_SEL_NONE);
-
-        /* Intersecting space is hyperslab selection.  Call the hyperslab
-         * routine to project to another hyperslab selection. */
-        if(H5S__hyper_project_intersection(src_space, dst_space, src_intersect_space, new_space, share_selection) < 0)
-            HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCLIP, FAIL, "can't project hyperslab onto destination selection")
+        /* Handle scalar dataspaces.  It should not be possible for the source
+         * intersect space or the source space to be scalar since scalar spaces
+         * only support all or none selections, and both of those cases are
+         * covered above, and the source intersect space must have the same
+         * rank, so it also cannot be scalar, as scalar dataspaces have a rank
+         * of 0. */
+        HDassert(H5S_GET_EXTENT_TYPE(src_space) != H5S_SCALAR);
+        HDassert(H5S_GET_EXTENT_TYPE(src_intersect_space) != H5S_SCALAR);
+
+        /* Check for scalar dst_space.  In this case we simply check if the
+         * (single) point selected in src_space intersects src_intersect_space,
+         * if so select all in new_space, otherwise select none. */
+        if(H5S_GET_EXTENT_TYPE(dst_space) == H5S_SCALAR) {
+            hsize_t coords_start[H5S_MAX_RANK];
+            hsize_t coords_end[H5S_MAX_RANK];
+            htri_t intersect;
+
+            /* Get source space bounds.  Should be a single point. */
+            if(H5S_SELECT_BOUNDS(src_space, coords_start, coords_end) < 0)
+                HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, "can't get source space bounds")
+            HDassert(0 == HDmemcmp(coords_start, coords_end, H5S_GET_EXTENT_NDIMS(src_space) * sizeof(coords_start[0])));
+
+            /* Check for intersection */
+            if((intersect = H5S_SELECT_INTERSECT_BLOCK(src_intersect_space, coords_start, coords_end)) < 0)
+                HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCOMPARE, FAIL, "can't check for intersection")
+
+            /* Select all or none as appropriate */
+            if(intersect) {
+                if(H5S_select_all(new_space, TRUE) < 0)
+                    HGOTO_ERROR(H5E_DATASPACE, H5E_CANTSET, FAIL, "can't select all")
+            } /* end if */
+            else
+                if(H5S_select_none(new_space) < 0)
+                    HGOTO_ERROR(H5E_DATASPACE, H5E_CANTDELETE, FAIL, "can't change selection")
+        } /* end if */
+        else {
+            /* If the source intersect space is a point selection, convert it to a
+             * hyperslab (discarding ordering).  We can get away with this because
+             * the order does not matter for the source intersect space */
+            /* Maybe we should just leave it as a point selection for the point by
+             * point algorithm?  The search through the selection in
+             * H5S_SELECT_INTERSECT_BLOCK will likely be O(N) either way.  -NAF */
+            if(H5S_GET_SELECT_TYPE(src_intersect_space) == H5S_SEL_POINTS) {
+                H5S_pnt_node_t *curr_pnt = src_intersect_space->select.sel_info.pnt_lst->head;
+
+                /* Create dataspace and copy extent */
+                if(NULL == (tmp_src_intersect_space = H5S_create(H5S_SIMPLE)))
+                    HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCREATE, FAIL, "unable to create temporary source intersect dataspace")
+                if(H5S__extent_copy_real(&tmp_src_intersect_space->extent, &src_intersect_space->extent, FALSE) < 0)
+                    HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCOPY, FAIL, "unable to copy source intersect space extent")
+
+                /* Iterate over points */
+                for(curr_pnt = src_intersect_space->select.sel_info.pnt_lst->head; curr_pnt; curr_pnt = curr_pnt->next)
+                    /* Add point to hyperslab selection */
+                    if(H5S_hyper_add_span_element(tmp_src_intersect_space, src_intersect_space->extent.rank, curr_pnt->pnt) < 0)
+                        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTSELECT, FAIL, "can't add point to temporary dataspace selection")
+
+                /* Redirect local src_intersect_space pointer (will not affect
+                 * calling function) */
+                src_intersect_space = tmp_src_intersect_space;
+            } /* end for */
+
+            /* By this point, src_intersect_space must be a hyperslab selection */
+            HDassert(H5S_GET_SELECT_TYPE(src_intersect_space) == H5S_SEL_HYPERSLABS);
+
+            /* If either the source space or the destination space is a point
+             * selection, iterate element by element */
+            if((H5S_GET_SELECT_TYPE(src_space) == H5S_SEL_POINTS)
+                    || (H5S_GET_SELECT_TYPE(dst_space) == H5S_SEL_POINTS)) {
+                hsize_t coords[H5S_MAX_RANK];
+                htri_t intersect;
+
+                /* Start with "none" selection */
+                if(H5S_select_none(new_space) < 0)
+                    HGOTO_ERROR(H5E_DATASPACE, H5E_CANTDELETE, FAIL, "can't change selection")
+
+                /* Initialize iterators */
+                if(H5S_select_iter_init(&ss_iter, src_space, 1, H5S_SEL_ITER_SHARE_WITH_DATASPACE) < 0)
+                    HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, FAIL, "can't initialize source space selection iterator")
+                ss_iter_init = TRUE;
+                if(H5S_select_iter_init(&ds_iter, dst_space, 1, H5S_SEL_ITER_SHARE_WITH_DATASPACE) < 0)
+                    HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, FAIL, "can't initialize destination space selection iterator")
+                ds_iter_init = TRUE;
+
+                /* Iterate over points */
+                do {
+                    HDassert(ss_iter.elmt_left > 0);
+                    HDassert(ss_iter.elmt_left > 0);
+
+                    /* Get SS coords */
+                    if(H5S_SELECT_ITER_COORDS(&ss_iter, coords) < 0)
+                        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, "can't get source selection coordinates")
+
+                    /* Check for intersection */
+                    if((intersect = H5S_SELECT_INTERSECT_BLOCK(src_intersect_space, coords, coords)) < 0)
+                        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCOMPARE, FAIL, "can't check for intersection")
+
+                    /* Add point if it intersects */
+                    if(intersect) {
+                        /* Get DS coords */
+                        if(H5S_SELECT_ITER_COORDS(&ds_iter, coords) < 0)
+                            HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, "can't get destination selection coordinates")
+
+                        /* Add point to new_space */
+                        if(H5S_select_elements(new_space, H5S_SELECT_APPEND, 1, coords) < 0)
+                            HGOTO_ERROR(H5E_DATASPACE, H5E_CANTSELECT, FAIL, "can't add point to new selection")
+                    } /* end if */
+
+                    /* Advance iterators */
+                    if(H5S_SELECT_ITER_NEXT(&ss_iter, 1) < 0)
+                        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTNEXT, FAIL, "can't advacne source selection iterator")
+                    ss_iter.elmt_left--;
+                    if(H5S_SELECT_ITER_NEXT(&ds_iter, 1) < 0)
+                        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTNEXT, FAIL, "can't advacne destination selection iterator")
+                    ds_iter.elmt_left--;
+                } while(ss_iter.elmt_left > 0);
+                HDassert(H5S_SELECT_ITER_NELMTS(&ds_iter) == 0);
+            } /* end if */
+            else {
+                HDassert(H5S_GET_SELECT_TYPE(src_space) != H5S_SEL_NONE);
+                HDassert(H5S_GET_SELECT_TYPE(dst_space) != H5S_SEL_NONE);
+
+                /* Source and destination selections are all or hyperslab,
+                 * intersecting selection is hyperslab.  Call the hyperslab routine
+                 * to project to another hyperslab selection. */
+                if(H5S__hyper_project_intersection(src_space, dst_space, src_intersect_space, new_space, share_selection) < 0)
+                    HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCLIP, FAIL, "can't project hyperslab onto destination selection")
+            } /* end else */
+        } /* end else */
     } /* end else */
 
     /* load the address of the new space into *new_space_ptr */
@@ -2657,6 +2780,14 @@ done:
         if(new_space && H5S_close(new_space) < 0)
             HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "unable to release dataspace")
 
+    /* General cleanup */
+    if(tmp_src_intersect_space && H5S_close(tmp_src_intersect_space) < 0)
+        HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "unable to release temporary dataspace")
+    if(ss_iter_init && H5S_SELECT_ITER_RELEASE(&ss_iter) < 0)
+        HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "unable to release source selection iterator")
+    if(ds_iter_init && H5S_SELECT_ITER_RELEASE(&ds_iter) < 0)
+        HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "unable to release destination selection iterator")
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5S_select_project_intersection() */
 
@@ -2668,8 +2799,7 @@ done:
  PURPOSE
     Projects the intersection of of the selections of src_space_id and
     src_intersect_space_id within the selection of src_space_id as a
-    selection within the selection of dst_space_id.  Currently does not
-    support point selections.
+    selection within the selection of dst_space_id.
 
  USAGE
     hid_t H5Sselect_project_intersection(src_space_id,dst_space_d,src_intersect_space_id)
@@ -2712,6 +2842,15 @@ H5Sselect_project_intersection(hid_t src_space_id, hid_t dst_space_id,
     if(NULL == (src_intersect_space = (H5S_t *)H5I_object_verify(src_intersect_space_id, H5I_DATASPACE)))
         HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL, "not a dataspace")
 
+    /* Check numbers of points selected matches in source and destination */
+    if(H5S_GET_SELECT_NPOINTS(src_space) != H5S_GET_SELECT_NPOINTS(dst_space))
+        HGOTO_ERROR(H5E_DATASPACE, H5E_BADVALUE, FAIL, "number of points selected in source space does not match that in destination space")
+
+    /* Check numbers of dimensions matches in source and source intersect spaces
+     */
+    if(H5S_GET_EXTENT_NDIMS(src_space) != H5S_GET_EXTENT_NDIMS(src_intersect_space))
+        HGOTO_ERROR(H5E_DATASPACE, H5E_BADVALUE, FAIL, "rank of source space does not match rank of source intersect space")
+
     /* Perform operation */
     if(H5S_select_project_intersection(src_space, dst_space,
             src_intersect_space, &proj_space, FALSE) < 0)
diff --git a/src/H5T.c b/src/H5T.c
index 3fc59d0..f378357 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -254,6 +254,7 @@
     dt->shared->u.atomic.u.r.rtype = H5R_OBJECT2;           \
     dt->shared->u.atomic.u.r.opaque = TRUE;                 \
     dt->shared->u.atomic.u.r.version = H5R_ENCODE_VERSION;  \
+    dt->shared->version = H5O_DTYPE_VERSION_4;              \
 }
 
 /* Define the code templates for the "SIZE_TMPL" in the H5T_INIT_TYPE macro */
@@ -3320,7 +3321,7 @@ done:
  *-------------------------------------------------------------------------
  */
 H5T_t *
-H5T_copy(const H5T_t *old_dt, H5T_copy_t method)
+H5T_copy(H5T_t *old_dt, H5T_copy_t method)
 {
     H5T_t           *new_dt = NULL, *tmp = NULL;
     H5T_shared_t    *reopened_fo = NULL;
diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index 6aea00e..4cc5f3c 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -3609,39 +3609,52 @@ H5T__conv_ref(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
                 for(elmtno = 0; elmtno < safe; elmtno++) {
                     size_t buf_size;
                     hbool_t dst_copy = FALSE;
+                    hbool_t is_nil; /* Whether sequence is "nil" */
 
-                    /* Get size of references */
-                    if(0 == (buf_size = src->shared->u.atomic.u.r.cls->getsize(
-                        src->shared->u.atomic.u.r.file, s, src->shared->size,
-                        dst->shared->u.atomic.u.r.file, &dst_copy)))
-                        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "incorrect size")
-
-                    /* Check if conversion buffer is large enough, resize if necessary. */
-                    if(conv_buf_size < buf_size) {
-                        conv_buf_size = buf_size;
-                        if(NULL == (conv_buf = H5FL_BLK_REALLOC(ref_seq, conv_buf, conv_buf_size)))
-                            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for type conversion")
-                        HDmemset(conv_buf, 0, conv_buf_size);
-                    } /* end if */
+                    /* Check for "nil" source sequence */
+                    if((*(src->shared->u.atomic.u.r.cls->isnull))(src->shared->u.atomic.u.r.file, s, &is_nil) < 0)
+                        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't check if reference data is 'nil'")
 
-                    if(dst_copy && (src->shared->u.atomic.u.r.loc == H5T_LOC_DISK)) {
-                        H5MM_memcpy(conv_buf, s, buf_size);
-                    } else {
-                        /* Read reference */
-                        if(src->shared->u.atomic.u.r.cls->read(
+                    if(is_nil) {
+
+                        /* Write "nil" sequence to destination location */
+                        if((*(dst->shared->u.atomic.u.r.cls->setnull))(dst->shared->u.atomic.u.r.file, d, b) < 0)
+                            HGOTO_ERROR(H5E_DATATYPE, H5E_WRITEERROR, FAIL, "can't set reference data to 'nil'")
+                    } /* end else-if */
+                    else {
+                        /* Get size of references */
+                        if(0 == (buf_size = src->shared->u.atomic.u.r.cls->getsize(
                             src->shared->u.atomic.u.r.file, s, src->shared->size,
-                            dst->shared->u.atomic.u.r.file, conv_buf, buf_size) < 0)
-                            HGOTO_ERROR(H5E_DATATYPE, H5E_READERROR, FAIL, "can't read reference data")
-                    }
+                            dst->shared->u.atomic.u.r.file, &dst_copy)))
+                            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "incorrect size")
+
+                        /* Check if conversion buffer is large enough, resize if necessary. */
+                        if(conv_buf_size < buf_size) {
+                            conv_buf_size = buf_size;
+                            if(NULL == (conv_buf = H5FL_BLK_REALLOC(ref_seq, conv_buf, conv_buf_size)))
+                                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for type conversion")
+                            HDmemset(conv_buf, 0, conv_buf_size);
+                        } /* end if */
 
-                    if(dst_copy && (dst->shared->u.atomic.u.r.loc == H5T_LOC_DISK)) {
-                        H5MM_memcpy(d, conv_buf, buf_size);
-                    } else {
-                        /* Write reference to destination location */
-                        if(dst->shared->u.atomic.u.r.cls->write(
-                            src->shared->u.atomic.u.r.file, conv_buf, buf_size, src->shared->u.atomic.u.r.rtype,
-                            dst->shared->u.atomic.u.r.file, d, dst->shared->size, b) < 0)
-                            HGOTO_ERROR(H5E_DATATYPE, H5E_WRITEERROR, FAIL, "can't write reference data")
+                        if(dst_copy && (src->shared->u.atomic.u.r.loc == H5T_LOC_DISK)) {
+                            H5MM_memcpy(conv_buf, s, buf_size);
+                        } else {
+                            /* Read reference */
+                            if(src->shared->u.atomic.u.r.cls->read(
+                                src->shared->u.atomic.u.r.file, s, src->shared->size,
+                                dst->shared->u.atomic.u.r.file, conv_buf, buf_size) < 0)
+                                HGOTO_ERROR(H5E_DATATYPE, H5E_READERROR, FAIL, "can't read reference data")
+                        }
+
+                        if(dst_copy && (dst->shared->u.atomic.u.r.loc == H5T_LOC_DISK)) {
+                            H5MM_memcpy(d, conv_buf, buf_size);
+                        } else {
+                            /* Write reference to destination location */
+                            if(dst->shared->u.atomic.u.r.cls->write(
+                                src->shared->u.atomic.u.r.file, conv_buf, buf_size, src->shared->u.atomic.u.r.rtype,
+                                dst->shared->u.atomic.u.r.file, d, dst->shared->size, b) < 0)
+                                HGOTO_ERROR(H5E_DATATYPE, H5E_WRITEERROR, FAIL, "can't write reference data")
+                        }
                     }
 
                     /* Advance pointers */
diff --git a/src/H5Tpkg.h b/src/H5Tpkg.h
index 1dbc229..39bff15 100644
--- a/src/H5Tpkg.h
+++ b/src/H5Tpkg.h
@@ -182,11 +182,15 @@ struct H5T_path_t {
 };
 
 /* Reference function pointers */
+typedef herr_t (*H5T_ref_isnullfunc_t)(const H5VL_object_t *file, const void *src_buf, hbool_t *isnull);
+typedef herr_t (*H5T_ref_setnullfunc_t)(H5VL_object_t *file, void *dst_buf, void *bg_buf);
 typedef size_t (*H5T_ref_getsizefunc_t)(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, hbool_t *dst_copy);
 typedef herr_t (*H5T_ref_readfunc_t)(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size);
 typedef herr_t (*H5T_ref_writefunc_t)(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5R_type_t src_type, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size, void *bg_buf);
 
 typedef struct H5T_ref_class_t {
+    H5T_ref_isnullfunc_t    isnull;     /* check if reference value is NIL */
+    H5T_ref_setnullfunc_t   setnull;    /* set a reference value to NIL */
     H5T_ref_getsizefunc_t   getsize;    /* get reference size (bytes)   */
     H5T_ref_readfunc_t      read;       /* read reference into buffer   */
     H5T_ref_writefunc_t     write;      /* write reference from buffer  */
diff --git a/src/H5Tprivate.h b/src/H5Tprivate.h
index 86bc174..d8e98af 100644
--- a/src/H5Tprivate.h
+++ b/src/H5Tprivate.h
@@ -109,7 +109,7 @@ H5_DLLVAR H5T_order_t H5T_native_order_g;
 
 /* Private functions */
 H5_DLL herr_t H5T_init(void);
-H5_DLL H5T_t *H5T_copy(const H5T_t *old_dt, H5T_copy_t method);
+H5_DLL H5T_t *H5T_copy(H5T_t *old_dt, H5T_copy_t method);
 H5_DLL herr_t H5T_lock(H5T_t *dt, hbool_t immutable);
 H5_DLL herr_t H5T_close(H5T_t *dt);
 H5_DLL herr_t H5T_close_real(H5T_t *dt);
diff --git a/src/H5Tref.c b/src/H5Tref.c
index b1bc9e8..6f21363 100644
--- a/src/H5Tref.c
+++ b/src/H5Tref.c
@@ -54,18 +54,24 @@ struct H5Tref_dsetreg {
 /* Local Prototypes */
 /********************/
 
+static herr_t H5T__ref_mem_isnull(const H5VL_object_t *src_file, const void *src_buf, hbool_t *isnull);
+static herr_t H5T__ref_mem_setnull(H5VL_object_t *dst_file, void *dst_buf, void *bg_buf);
 static size_t H5T__ref_mem_getsize(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, hbool_t *dst_copy);
 static herr_t H5T__ref_mem_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size);
 static herr_t H5T__ref_mem_write(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5R_type_t src_type, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size, void *bg_buf);
 
+static herr_t H5T__ref_disk_isnull(const H5VL_object_t *src_file, const void *src_buf, hbool_t *isnull);
+static herr_t H5T__ref_disk_setnull(H5VL_object_t *dst_file, void *dst_buf, void *bg_buf);
 static size_t H5T__ref_disk_getsize(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, hbool_t *dst_copy);
 static herr_t H5T__ref_disk_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size);
 static herr_t H5T__ref_disk_write(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5R_type_t src_type, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size, void *bg_buf);
 
 /* For compatibility */
+static herr_t H5T__ref_obj_disk_isnull(const H5VL_object_t *src_file, const void *src_buf, hbool_t *isnull);
 static size_t H5T__ref_obj_disk_getsize(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, hbool_t *dst_copy);
 static herr_t H5T__ref_obj_disk_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size);
 
+static herr_t H5T__ref_dsetreg_disk_isnull(const H5VL_object_t *src_file, const void *src_buf, hbool_t *isnull);
 static size_t H5T__ref_dsetreg_disk_getsize(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, hbool_t *dst_copy);
 static herr_t H5T__ref_dsetreg_disk_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size);
 
@@ -75,24 +81,32 @@ static herr_t H5T__ref_dsetreg_disk_read(H5VL_object_t *src_file, const void *sr
 
 /* Class for reference in memory */
 static const H5T_ref_class_t H5T_ref_mem_g = {
+    H5T__ref_mem_isnull,            /* 'isnull' */
+    H5T__ref_mem_setnull,           /* 'setnull' */
     H5T__ref_mem_getsize,           /* 'getsize' */
     H5T__ref_mem_read,              /* 'read' */
     H5T__ref_mem_write              /* 'write' */
 };
 
 static const H5T_ref_class_t H5T_ref_disk_g = {
+    H5T__ref_disk_isnull,           /* 'isnull' */
+    H5T__ref_disk_setnull,          /* 'setnull' */
     H5T__ref_disk_getsize,          /* 'getsize' */
     H5T__ref_disk_read,             /* 'read' */
     H5T__ref_disk_write             /* 'write' */
 };
 
 static const H5T_ref_class_t H5T_ref_obj_disk_g = {
+    H5T__ref_obj_disk_isnull,       /* 'isnull' */
+    NULL,                           /* 'setnull' */
     H5T__ref_obj_disk_getsize,      /* 'getsize' */
     H5T__ref_obj_disk_read,         /* 'read' */
     NULL                            /* 'write' */
 };
 
 static const H5T_ref_class_t H5T_ref_dsetreg_disk_g = {
+    H5T__ref_dsetreg_disk_isnull,   /* 'isnull' */
+    NULL,                           /* 'setnull' */
     H5T__ref_dsetreg_disk_getsize,  /* 'getsize' */
     H5T__ref_dsetreg_disk_read,     /* 'read' */
     NULL                            /* 'write' */
@@ -268,6 +282,57 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5T__ref_mem_isnull
+ *
+ * Purpose: Check if it's a NULL / uninitialized reference.
+ *
+ * Return:  Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5T__ref_mem_isnull(const H5VL_object_t H5_ATTR_UNUSED *src_file,
+    const void *src_buf, hbool_t *isnull)
+{
+    const unsigned char zeros[H5T_REF_MEM_SIZE] = { 0 };
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Check parameters */
+    HDassert(src_buf);
+    HDassert(isnull);
+
+    *isnull = (0 == HDmemcmp(src_buf, zeros, H5T_REF_MEM_SIZE)) ? TRUE : FALSE;
+
+    FUNC_LEAVE_NOAPI(ret_value)
+}   /* end H5T__ref_mem_isnull() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5T__ref_mem_setnull
+ *
+ * Purpose: Set a reference as NULL / uninitialized.
+ *
+ * Return:  Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5T__ref_mem_setnull(H5VL_object_t H5_ATTR_UNUSED *dst_file, void *dst_buf,
+    H5_ATTR_UNUSED void *bg_buf)
+{
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC_NOERR
+
+    HDmemset(dst_buf, 0, H5T_REF_MEM_SIZE);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+}   /* end H5T__ref_mem_setnull() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5T__ref_mem_getsize
  *
  * Purpose:	Retrieves the size of a memory based reference.
@@ -280,10 +345,12 @@ static size_t
 H5T__ref_mem_getsize(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf,
     size_t H5_ATTR_UNUSED src_size, H5VL_object_t *dst_file, hbool_t *dst_copy)
 {
-    H5F_t *src_f;
-    H5F_t *dst_f;
     H5VL_object_t *vol_obj = NULL;
     const H5R_ref_priv_t *src_ref = (const H5R_ref_priv_t *)src_buf;
+    hbool_t files_equal = FALSE;
+    char file_name_buf_static[256];
+    char *file_name_buf_dyn = NULL;
+    ssize_t file_name_len;
     unsigned flags = 0;
     size_t ret_value = 0;
 
@@ -296,27 +363,43 @@ H5T__ref_mem_getsize(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf
     if(NULL == (vol_obj = H5VL_vol_object(src_ref->loc_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid location identifier")
 
-    /* We should assert here that the terminal connector is H5VL_NATIVE once
-     * there is a facility to do so -NAF 2019/10/30 */
-
-    /* Retrieve files from VOL objects */
-    if(NULL == (src_f = (H5F_t *)H5VL_object_data(vol_obj)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
-    if(NULL == (dst_f = (H5F_t *)H5VL_object_data(dst_file)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
-
     /* Set external flag if referenced file is not destination file */
-    flags |= (src_f->shared != dst_f->shared) ? H5R_IS_EXTERNAL : 0;
+    if(H5VL_file_specific(vol_obj, H5VL_FILE_IS_EQUAL, H5P_DATASET_XFER_DEFAULT, NULL, dst_file, &files_equal) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCOMPARE, 0, "can't check if files are equal")
+    flags |= !files_equal ? H5R_IS_EXTERNAL : 0;
 
     /* Force re-calculating encoding size if any flags are set */
     if(flags || !src_ref->encode_size) {
         /* Pass the correct encoding version for the selection depending on the
          * file libver bounds, this is later retrieved in H5S hyper encode */
-        if(src_ref->type == (int8_t)H5R_DATASET_REGION2)
-            H5CX_set_libver_bounds(dst_f);
+        if(src_ref->type == (int8_t)H5R_DATASET_REGION2) {
+            /* Temporary hack to check if this is the native connector.  We need to
+             * add a way to check if the terminal connector is native.  For now this
+             * will break passthroughs, but it's needed for other VOL connectors to
+             * work.  -NAF */
+            if(dst_file->connector->cls->value == H5VL_NATIVE_VALUE) {
+                H5F_t *dst_f;
+
+                if(NULL == (dst_f = (H5F_t *)H5VL_object_data(dst_file)))
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
+                H5CX_set_libver_bounds(dst_f);
+            } /* end if */
+            else
+                H5CX_set_libver_bounds(NULL);
+        } /* end if */
+
+        /* Get file name */
+        if(H5VL_file_get(vol_obj, H5VL_FILE_GET_NAME, H5P_DATASET_XFER_DEFAULT, NULL, H5I_FILE, sizeof(file_name_buf_static), file_name_buf_static, &file_name_len) < 0)
+            HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, 0, "can't get file name")
+        if(file_name_len >= (ssize_t)sizeof(file_name_buf_static)) {
+            if(NULL == (file_name_buf_dyn = (char *)H5MM_malloc((size_t)file_name_len + 1)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, 0, "can't allocate space for file name")
+            if(H5VL_file_get(vol_obj, H5VL_FILE_GET_NAME, H5P_DATASET_XFER_DEFAULT, NULL, H5I_FILE, (size_t)file_name_len + 1, file_name_buf_dyn, &file_name_len) < 0)
+                HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, 0, "can't get file name")
+        } /* end if */
 
         /* Determine encoding size */
-        if(H5R__encode(H5F_ACTUAL_NAME(src_f), src_ref, NULL, &ret_value, flags) < 0)
+        if(H5R__encode(file_name_buf_dyn ? file_name_buf_dyn : file_name_buf_static, src_ref, NULL, &ret_value, flags) < 0)
             HGOTO_ERROR(H5E_REFERENCE, H5E_CANTENCODE, 0, "unable to determine encoding size")
     } else {
         /* Can do a direct copy and skip blob decoding */
@@ -328,6 +411,8 @@ H5T__ref_mem_getsize(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf
     }
 
 done:
+    H5MM_xfree(file_name_buf_dyn);
+
     FUNC_LEAVE_NOAPI(ret_value)
 }   /* end H5T__ref_mem_getsize() */
 
@@ -346,10 +431,12 @@ H5T__ref_mem_read(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf,
     size_t H5_ATTR_UNUSED src_size, H5VL_object_t *dst_file, void *dst_buf,
     size_t dst_size)
 {
-    H5F_t *src_f;
-    H5F_t *dst_f;
     H5VL_object_t *vol_obj = NULL;
     const H5R_ref_priv_t *src_ref = (const H5R_ref_priv_t *)src_buf;
+    hbool_t files_equal = FALSE;
+    char file_name_buf_static[256];
+    char *file_name_buf_dyn = NULL;
+    ssize_t file_name_len;
     unsigned flags = 0;
     herr_t ret_value = SUCCEED;
 
@@ -365,28 +452,46 @@ H5T__ref_mem_read(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf,
     if(NULL == (vol_obj = H5VL_vol_object(src_ref->loc_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid location identifier")
 
-    /* We should assert here that the terminal connector is H5VL_NATIVE once
-     * there is a facility to do so -NAF 2019/10/30 */
-
-    /* Retrieve files from VOL objects */
-    if(NULL == (src_f = (H5F_t *)H5VL_object_data(vol_obj)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
-    if(NULL == (dst_f = (H5F_t *)H5VL_object_data(dst_file)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
-
     /* Set external flag if referenced file is not destination file */
-    flags |= (src_f->shared != dst_f->shared) ? H5R_IS_EXTERNAL : 0;
+    if(H5VL_file_specific(vol_obj, H5VL_FILE_IS_EQUAL, H5P_DATASET_XFER_DEFAULT, NULL, dst_file, &files_equal) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCOMPARE, FAIL, "can't check if files are equal")
+    flags |= !files_equal ? H5R_IS_EXTERNAL : 0;
 
     /* Pass the correct encoding version for the selection depending on the
      * file libver bounds, this is later retrieved in H5S hyper encode */
-    if(src_ref->type == (int8_t)H5R_DATASET_REGION2)
-        H5CX_set_libver_bounds(dst_f);
+    if(src_ref->type == (int8_t)H5R_DATASET_REGION2) {
+        /* Temporary hack to check if this is the native connector.  We need to
+         * add a way to check if the terminal connector is native.  For now this
+         * will break passthroughs, but it's needed for other VOL connectors to
+         * work.  -NAF */
+        if(dst_file->connector->cls->value == H5VL_NATIVE_VALUE) {
+            H5F_t *dst_f;
+
+            if(NULL == (dst_f = (H5F_t *)H5VL_object_data(dst_file)))
+                HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
+            H5CX_set_libver_bounds(dst_f);
+        } /* end if */
+        else
+            H5CX_set_libver_bounds(NULL);
+    } /* end if */
+
+    /* Get file name */
+    if(H5VL_file_get(vol_obj, H5VL_FILE_GET_NAME, H5P_DATASET_XFER_DEFAULT, NULL, H5I_FILE, sizeof(file_name_buf_static), file_name_buf_static, &file_name_len) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, 0, "can't get file name")
+    if(file_name_len >= (ssize_t)sizeof(file_name_buf_static)) {
+        if(NULL == (file_name_buf_dyn = (char *)H5MM_malloc((size_t)file_name_len + 1)))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, 0, "can't allocate space for file name")
+        if(H5VL_file_get(vol_obj, H5VL_FILE_GET_NAME, H5P_DATASET_XFER_DEFAULT, NULL, H5I_FILE, (size_t)file_name_len + 1, file_name_buf_dyn, &file_name_len) < 0)
+            HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, 0, "can't get file name")
+    } /* end if */
 
     /* Encode reference */
-    if(H5R__encode(H5F_ACTUAL_NAME(src_f), src_ref, (unsigned char *)dst_buf, &dst_size, flags) < 0)
+    if(H5R__encode(file_name_buf_dyn ? file_name_buf_dyn : file_name_buf_static, src_ref, (unsigned char *)dst_buf, &dst_size, flags) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTENCODE, FAIL, "Cannot encode reference")
 
 done:
+    H5MM_xfree(file_name_buf_dyn);
+
     FUNC_LEAVE_NOAPI(ret_value)
 }   /* end H5T__ref_mem_read() */
 
@@ -468,7 +573,7 @@ H5T__ref_mem_write(H5VL_object_t *src_file, const void *src_buf, size_t src_size
     /* If no filename set, this is not an external reference */
     if(NULL == H5R_REF_FILENAME(dst_ref)) {
         /* TODO temporary hack to retrieve file object */
-        if((file_id = H5F__get_file_id(src_f, FALSE)) < 0)
+        if((file_id = H5F_get_file_id(src_file, H5I_FILE, FALSE)) < 0)
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
 
         /* Attach loc ID to reference and hold reference to it */
@@ -484,6 +589,96 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5T__ref_disk_isnull
+ *
+ * Purpose: Check if it's a NULL / uninitialized reference.
+ *
+ * Return:  Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5T__ref_disk_isnull(const H5VL_object_t *src_file, const void *src_buf,
+    hbool_t *isnull)
+{
+    const uint8_t *p = (const uint8_t *)src_buf;
+    H5R_type_t ref_type;
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Check parameters */
+    HDassert(src_file);
+    HDassert(src_buf);
+    HDassert(isnull);
+
+    /* Try to check encoded reference type */
+    ref_type = (H5R_type_t)*p++;
+    if(ref_type) {
+        /* This is a valid reference */
+        *isnull = FALSE;
+    } else {
+        /* Skip the size / header */
+        p = (const uint8_t *)src_buf + H5R_ENCODE_HEADER_SIZE + H5_SIZEOF_UINT32_T;
+
+        /* Check if blob ID is "nil" */
+        if(H5VL_blob_specific(src_file, (void *)p, H5VL_BLOB_ISNULL, isnull) < 0)
+            HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "unable to check if a blob ID is 'nil'")
+    }
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+}   /* end H5T__ref_disk_isnull() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5T__ref_disk_setnull
+ *
+ * Purpose: Set a reference as NULL / uninitialized.
+ *
+ * Return:  Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5T__ref_disk_setnull(H5VL_object_t *dst_file, void *dst_buf, void *bg_buf)
+{
+    uint8_t *q = (uint8_t *)dst_buf;
+    uint8_t *p_bg = (uint8_t *)bg_buf;
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    HDassert(dst_file);
+    HDassert(dst_buf);
+
+    /* TODO Should get rid of bg stuff */
+    if(p_bg) {
+        /* Skip the size / header */
+        p_bg += (H5_SIZEOF_UINT32_T + H5R_ENCODE_HEADER_SIZE);
+
+        /* Remove blob for old data */
+        if(H5VL_blob_specific(dst_file, (void *)p_bg, H5VL_BLOB_DELETE) < 0)
+            HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREMOVE, FAIL, "unable to delete blob")
+    } /* end if */
+
+    /* Copy header manually so that it does not get encoded into the blob */
+    HDmemset(q, 0, H5R_ENCODE_HEADER_SIZE);
+    q += H5R_ENCODE_HEADER_SIZE;
+
+    /* Set the size */
+    UINT32ENCODE(q, 0);
+
+    /* Set blob ID to "nil" */
+    if(H5VL_blob_specific(dst_file, q, H5VL_BLOB_SETNULL) < 0)
+        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTSET, FAIL, "unable to set a blob ID to 'nil'")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+}   /* end H5T__ref_disk_setnull() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5T__ref_disk_getsize
  *
  * Purpose:	Retrieves the length of a disk based reference.
@@ -562,7 +757,7 @@ H5T__ref_disk_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size
     q += H5R_ENCODE_HEADER_SIZE;
     blob_size -= H5R_ENCODE_HEADER_SIZE;
 
-    /* Skip the length of the sequence */
+    /* Skip the size */
     p += H5_SIZEOF_UINT32_T;
     HDassert(src_size > (H5R_ENCODE_HEADER_SIZE + H5_SIZEOF_UINT32_T));
 
@@ -606,10 +801,10 @@ H5T__ref_disk_write(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf,
     if(p_bg) {
         size_t p_buf_size_left = dst_size;
 
-        /* Skip the length of the reference */
-        p_bg += H5_SIZEOF_UINT32_T;
-        HDassert(p_buf_size_left > H5_SIZEOF_UINT32_T);
-        p_buf_size_left -= H5_SIZEOF_UINT32_T;
+        /* Skip the size / header */
+        p_bg += (H5_SIZEOF_UINT32_T + H5R_ENCODE_HEADER_SIZE);
+        HDassert(p_buf_size_left > (H5_SIZEOF_UINT32_T + H5R_ENCODE_HEADER_SIZE));
+        p_buf_size_left -= (H5_SIZEOF_UINT32_T + H5R_ENCODE_HEADER_SIZE);
 
         /* Remove blob for old data */
         if(H5VL_blob_specific(dst_file, (void *)p_bg, H5VL_BLOB_DELETE) < 0)
@@ -638,6 +833,48 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5T__ref_obj_disk_isnull
+ *
+ * Purpose: Check if it's a NULL / uninitialized reference.
+ *
+ * Return:  Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t H5T__ref_obj_disk_isnull(const H5VL_object_t *src_file,
+    const void *src_buf, hbool_t *isnull)
+{
+    H5F_t *src_f;
+    const uint8_t *p = (const uint8_t *)src_buf;
+    haddr_t addr;
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Check parameters */
+    HDassert(src_file);
+    HDassert(src_buf);
+    HDassert(isnull);
+
+    /* We should assert here that the terminal connector is H5VL_NATIVE once
+     * there is a facility to do so -NAF 2019/10/30 */
+
+    /* Retrieve file from VOL object */
+    if(NULL == (src_f = (H5F_t *)H5VL_object_data(src_file)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid VOL object")
+
+    /* Get the object address */
+    H5F_addr_decode(src_f, &p, &addr);
+
+    /* Check if heap address is 'nil' */
+    *isnull = (addr == 0) ? TRUE : FALSE;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+}   /* end H5T__ref_obj_disk_isnull() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5T__ref_obj_disk_getsize
  *
  * Purpose: Retrieves the length of a disk based reference.
@@ -718,6 +955,49 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5T__ref_dsetreg_disk_isnull
+ *
+ * Purpose: Check if it's a NULL / uninitialized reference.
+ *
+ * Return:  Non-negative on success/Negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5T__ref_dsetreg_disk_isnull(const H5VL_object_t *src_file, const void *src_buf,
+    hbool_t *isnull)
+{
+    H5F_t *src_f;
+    const uint8_t *p = (const uint8_t *)src_buf;
+    haddr_t addr;
+    herr_t ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Check parameters */
+    HDassert(src_file);
+    HDassert(src_buf);
+    HDassert(isnull);
+
+    /* We should assert here that the terminal connector is H5VL_NATIVE once
+     * there is a facility to do so -NAF 2019/10/30 */
+
+    /* Retrieve file from VOL object */
+    if(NULL == (src_f = (H5F_t *)H5VL_object_data(src_file)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid VOL object")
+
+    /* Get the heap address */
+    H5F_addr_decode(src_f, &p, &addr);
+
+    /* Check if heap address is 'nil' */
+    *isnull = (addr == 0) ? TRUE : FALSE;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+}   /* end H5T__ref_dsetreg_disk_isnull() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5T__ref_dsetreg_disk_getsize
  *
  * Purpose: Retrieves the length of a disk based reference.
@@ -727,28 +1007,28 @@ done:
  *-------------------------------------------------------------------------
  */
 static size_t
-H5T__ref_dsetreg_disk_getsize(H5VL_object_t H5_ATTR_UNUSED *file,
-    const void H5_ATTR_UNUSED *buf, size_t H5_ATTR_UNUSED buf_size,
+H5T__ref_dsetreg_disk_getsize(H5VL_object_t H5_ATTR_UNUSED *src_file,
+    const void H5_ATTR_UNUSED *src_buf, size_t H5_ATTR_UNUSED src_size,
     H5VL_object_t H5_ATTR_UNUSED *dst_file, hbool_t H5_ATTR_UNUSED *dst_copy)
 {
     size_t ret_value = sizeof(struct H5Tref_dsetreg);
 
     FUNC_ENTER_STATIC
 
-    HDassert(buf);
+    HDassert(src_buf);
 
 #ifndef NDEBUG
     {
-        H5F_t *f;
+        H5F_t *src_f;
 
         /* We should assert here that the terminal connector is H5VL_NATIVE once
          * there is a facility to do so -NAF 2019/10/30 */
 
         /* Retrieve file from VOL object */
-        if(NULL == (f = (H5F_t *)H5VL_object_data(file)))
+        if(NULL == (src_f = (H5F_t *)H5VL_object_data(src_file)))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
 
-        HDassert(buf_size == H5T_REF_DSETREG_DISK_SIZE(f));
+        HDassert(src_size == H5T_REF_DSETREG_DISK_SIZE(src_f));
     } /* end block */
 #endif /* NDEBUG */
 
@@ -827,3 +1107,4 @@ H5T_ref_reclaim(void *elem, const H5T_t *dt)
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5T_ref_reclaim() */
+
diff --git a/src/H5VLcallback.c b/src/H5VLcallback.c
index 8d7368b..77df207 100644
--- a/src/H5VLcallback.c
+++ b/src/H5VLcallback.c
@@ -101,6 +101,8 @@ static void * H5VL__file_open(const H5VL_class_t *cls, const char *name,
     unsigned flags, hid_t fapl_id, hid_t dxpl_id, void **req);
 static herr_t H5VL__file_get(void *obj, const H5VL_class_t *cls, H5VL_file_get_t get_type, 
     hid_t dxpl_id, void **req, va_list arguments);
+static herr_t H5VL__file_specific_wrap_va_list(void *obj, const H5VL_class_t *cls,
+    H5VL_file_specific_t specific_type,  hid_t dxpl_id, void **req, ...);
 static herr_t H5VL__file_specific(void *obj, const H5VL_class_t *cls, H5VL_file_specific_t specific_type, 
     hid_t dxpl_id, void **req, va_list arguments);
 static herr_t H5VL__file_optional(void *obj, const H5VL_class_t *cls, hid_t dxpl_id,
@@ -2989,6 +2991,43 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5VL__file_specific_wrap_va_list
+ *
+ * Purpose:     Perform File specific operations through the VOL.  Just
+ *              starts a va_list and passes it to the connector's
+ *              callback.  Needed when the VOL layer needs to replace one
+ *              of the variable arguments.
+ *
+ * Return:      Success:    Non-negative
+ *              Failure:    Negative
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5VL__file_specific_wrap_va_list(void *obj, const H5VL_class_t *cls,
+    H5VL_file_specific_t specific_type,  hid_t dxpl_id, void **req, ...)
+{
+    va_list arguments;                  /* Argument list passed from the API call */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Start access to the varargs, so they are available in all situations below */
+    HDva_start(arguments, req);
+
+    /* Call the corresponding VOL callback */
+    if((cls->file_cls.specific)(obj, specific_type, dxpl_id, req, arguments) < 0)
+        HGOTO_ERROR(H5E_VOL, H5E_CANTOPERATE, FAIL, "file specific failed")
+
+done:
+    /* End access to the va_list */
+    HDva_end(arguments);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5VL__file_specific_wrap_va_list() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5VL__file_specific
  *
  * Purpose:	Perform File specific operations through the VOL
@@ -3010,9 +3049,38 @@ H5VL__file_specific(void *obj, const H5VL_class_t *cls, H5VL_file_specific_t spe
     if(NULL == cls->file_cls.specific)
         HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "VOL connector has no 'file specific' method")
 
-    /* Call the corresponding VOL callback */
-    if((cls->file_cls.specific)(obj, specific_type, dxpl_id, req, arguments) < 0)
-        HGOTO_ERROR(H5E_VOL, H5E_CANTOPERATE, FAIL, "file specific failed")
+    /* Special handling for file is equal */
+    if(specific_type == H5VL_FILE_IS_EQUAL) {
+        va_list             tmp_args;       /* Argument list passed from the API call */
+        H5VL_object_t       *vol_obj2;      /* Second VOL object */
+        hbool_t             *is_equal;      /* Output variable */
+        int                 cmp_value;      /* Comparison result */
+
+        /* Get parameters */
+        HDva_copy(tmp_args, arguments);
+        vol_obj2 = HDva_arg(tmp_args, H5VL_object_t *);
+        is_equal = HDva_arg(tmp_args, hbool_t *);
+        HDva_end(tmp_args);
+
+        HDassert(vol_obj2);
+
+        /* Compare connector classes */
+        if(H5VL_cmp_connector_cls(&cmp_value, cls, vol_obj2->connector->cls) < 0)
+            HGOTO_ERROR(H5E_VOL, H5E_CANTCOMPARE, FAIL, "can't compare connector classes")
+
+        /* If the classes are different the files are different */
+        if(cmp_value)
+            *is_equal = FALSE;
+        else
+            /* Make callback (need to extract data from vol_obj2 and redo the
+             * va_list) */
+            if(H5VL__file_specific_wrap_va_list(obj, cls, specific_type, dxpl_id, req, vol_obj2->data, is_equal) < 0)
+                HGOTO_ERROR(H5E_VOL, H5E_CANTOPERATE, FAIL, "file specific failed")
+    } /* end if */
+    else
+        /* Call the corresponding VOL callback */
+        if((cls->file_cls.specific)(obj, specific_type, dxpl_id, req, arguments) < 0)
+            HGOTO_ERROR(H5E_VOL, H5E_CANTOPERATE, FAIL, "file specific failed")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5VLconnector.h b/src/H5VLconnector.h
index 13cb2b5..373eb44 100644
--- a/src/H5VLconnector.h
+++ b/src/H5VLconnector.h
@@ -52,7 +52,9 @@
 
 /* type for tokens. Token are unique and permanent identifiers that are
  * used to reference HDF5 objects. */
-typedef unsigned char H5VL_token_t[H5VL_MAX_TOKEN_SIZE];
+typedef struct {
+    char __data[H5VL_MAX_TOKEN_SIZE];
+} H5VL_token_t;
 
 /* types for attribute GET callback */
 typedef enum H5VL_attr_get_t {
@@ -122,7 +124,8 @@ typedef enum H5VL_file_specific_t {
     H5VL_FILE_MOUNT,                        /* Mount a file                     */
     H5VL_FILE_UNMOUNT,                      /* Unmount a file                   */
     H5VL_FILE_IS_ACCESSIBLE,                /* Check if a file is accessible    */
-    H5VL_FILE_DELETE                        /* Delete a file                    */
+    H5VL_FILE_DELETE,                       /* Delete a file                    */
+    H5VL_FILE_IS_EQUAL                      /* Check if two files are the same  */
 } H5VL_file_specific_t;
 
 /* types for group GET callback */
@@ -160,6 +163,7 @@ typedef enum H5VL_link_specific_t {
 
 /* types for object GET callback */
 typedef enum H5VL_object_get_t {
+    H5VL_OBJECT_GET_FILE,              /* object file                       */
     H5VL_OBJECT_GET_NAME,              /* object name                       */
     H5VL_OBJECT_GET_TYPE               /* object type                       */
 } H5VL_object_get_t;
@@ -211,7 +215,7 @@ typedef struct H5VL_loc_by_idx {
 } H5VL_loc_by_idx_t;
 
 typedef struct H5VL_loc_by_token {
-    void *token;
+    H5VL_token_t *token;
 } H5VL_loc_by_token_t;
 
 /* Structure to hold parameters for object locations.
diff --git a/src/H5VLint.c b/src/H5VLint.c
index 733a2b5..284b266 100644
--- a/src/H5VLint.c
+++ b/src/H5VLint.c
@@ -1639,6 +1639,12 @@ H5VL_cmp_connector_cls(int *cmp_value, const H5VL_class_t *cls1, const H5VL_clas
     HDassert(cls1);
     HDassert(cls2);
 
+    /* If the pointers are the same the classes are the same */
+    if(cls1 == cls2) {
+        *cmp_value = 0;
+        HGOTO_DONE(SUCCEED);
+    } /* end if */
+
     /* Compare connector "values" */
     if(cls1->value < cls2->value) {
         *cmp_value = -1;
diff --git a/src/H5VLnative.h b/src/H5VLnative.h
index 5b51e66..73cec8d 100644
--- a/src/H5VLnative.h
+++ b/src/H5VLnative.h
@@ -57,25 +57,24 @@ typedef int H5VL_native_file_optional_t;
 #define H5VL_NATIVE_FILE_GET_MDC_SIZE                   7   /* H5Fget_mdc_size                      */
 #define H5VL_NATIVE_FILE_GET_SIZE                       8   /* H5Fget_filesize                      */
 #define H5VL_NATIVE_FILE_GET_VFD_HANDLE                 9   /* H5Fget_vfd_handle                    */
-#define H5VL_NATIVE_FILE_GET_FILE_ID                    10  /* H5Fget_file_id                       */
-#define H5VL_NATIVE_FILE_RESET_MDC_HIT_RATE             11  /* H5Freset_mdc_hit_rate_stats          */
-#define H5VL_NATIVE_FILE_SET_MDC_CONFIG                 12  /* H5Fset_mdc_config                    */
-#define H5VL_NATIVE_FILE_GET_METADATA_READ_RETRY_INFO   13  /* H5Fget_metadata_read_retry_info      */
-#define H5VL_NATIVE_FILE_START_SWMR_WRITE               14  /* H5Fstart_swmr_write                  */
-#define H5VL_NATIVE_FILE_START_MDC_LOGGING              15  /* H5Fstart_mdc_logging                 */
-#define H5VL_NATIVE_FILE_STOP_MDC_LOGGING               16  /* H5Fstop_mdc_logging                  */
-#define H5VL_NATIVE_FILE_GET_MDC_LOGGING_STATUS         17  /* H5Fget_mdc_logging_status            */
-#define H5VL_NATIVE_FILE_FORMAT_CONVERT                 18  /* H5Fformat_convert                    */
-#define H5VL_NATIVE_FILE_RESET_PAGE_BUFFERING_STATS     19  /* H5Freset_page_buffering_stats        */
-#define H5VL_NATIVE_FILE_GET_PAGE_BUFFERING_STATS       20  /* H5Fget_page_buffering_stats          */
-#define H5VL_NATIVE_FILE_GET_MDC_IMAGE_INFO             21  /* H5Fget_mdc_image_info                */
-#define H5VL_NATIVE_FILE_GET_EOA                        22  /* H5Fget_eoa                           */
-#define H5VL_NATIVE_FILE_INCR_FILESIZE                  23  /* H5Fincrement_filesize                */
-#define H5VL_NATIVE_FILE_SET_LIBVER_BOUNDS              24  /* H5Fset_latest_format/libver_bounds   */
-#define H5VL_NATIVE_FILE_GET_MIN_DSET_OHDR_FLAG         25  /* H5Fget_dset_no_attrs_hint            */
-#define H5VL_NATIVE_FILE_SET_MIN_DSET_OHDR_FLAG         26  /* H5Fset_dset_no_attrs_hint            */
-#define H5VL_NATIVE_FILE_GET_MPI_ATOMICITY              27  /* H5Fget_mpi_atomicity                 */
-#define H5VL_NATIVE_FILE_SET_MPI_ATOMICITY              28  /* H5Fset_mpi_atomicity                 */
+#define H5VL_NATIVE_FILE_RESET_MDC_HIT_RATE             10  /* H5Freset_mdc_hit_rate_stats          */
+#define H5VL_NATIVE_FILE_SET_MDC_CONFIG                 11  /* H5Fset_mdc_config                    */
+#define H5VL_NATIVE_FILE_GET_METADATA_READ_RETRY_INFO   12  /* H5Fget_metadata_read_retry_info      */
+#define H5VL_NATIVE_FILE_START_SWMR_WRITE               13  /* H5Fstart_swmr_write                  */
+#define H5VL_NATIVE_FILE_START_MDC_LOGGING              14  /* H5Fstart_mdc_logging                 */
+#define H5VL_NATIVE_FILE_STOP_MDC_LOGGING               15  /* H5Fstop_mdc_logging                  */
+#define H5VL_NATIVE_FILE_GET_MDC_LOGGING_STATUS         16  /* H5Fget_mdc_logging_status            */
+#define H5VL_NATIVE_FILE_FORMAT_CONVERT                 17  /* H5Fformat_convert                    */
+#define H5VL_NATIVE_FILE_RESET_PAGE_BUFFERING_STATS     18  /* H5Freset_page_buffering_stats        */
+#define H5VL_NATIVE_FILE_GET_PAGE_BUFFERING_STATS       19  /* H5Fget_page_buffering_stats          */
+#define H5VL_NATIVE_FILE_GET_MDC_IMAGE_INFO             20  /* H5Fget_mdc_image_info                */
+#define H5VL_NATIVE_FILE_GET_EOA                        21  /* H5Fget_eoa                           */
+#define H5VL_NATIVE_FILE_INCR_FILESIZE                  22  /* H5Fincrement_filesize                */
+#define H5VL_NATIVE_FILE_SET_LIBVER_BOUNDS              23  /* H5Fset_latest_format/libver_bounds   */
+#define H5VL_NATIVE_FILE_GET_MIN_DSET_OHDR_FLAG         24  /* H5Fget_dset_no_attrs_hint            */
+#define H5VL_NATIVE_FILE_SET_MIN_DSET_OHDR_FLAG         25  /* H5Fset_dset_no_attrs_hint            */
+#define H5VL_NATIVE_FILE_GET_MPI_ATOMICITY              26  /* H5Fget_mpi_atomicity                 */
+#define H5VL_NATIVE_FILE_SET_MPI_ATOMICITY              27  /* H5Fset_mpi_atomicity                 */
 
 /* Typedef and values for native VOL connector group optional VOL operations */
 typedef int H5VL_native_group_optional_t;
diff --git a/src/H5VLnative_file.c b/src/H5VLnative_file.c
index 094722e..588d59f 100644
--- a/src/H5VLnative_file.c
+++ b/src/H5VLnative_file.c
@@ -418,6 +418,19 @@ H5VL__native_file_specific(void *obj, H5VL_file_specific_t specific_type,
                 break;
             }
 
+        /* Check if two files are the same */
+        case H5VL_FILE_IS_EQUAL:
+            {
+                H5F_t *file2 = (H5F_t *)HDva_arg(arguments, void *);
+                hbool_t *is_equal = HDva_arg(arguments, hbool_t *);
+
+                if(!obj || !file2)
+                    *is_equal = FALSE;
+                else
+                    *is_equal = (((H5F_t *)obj)->shared == file2->shared);
+                break;
+            }
+
         default:
             HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "invalid specific operation")
     } /* end switch */
@@ -578,20 +591,6 @@ H5VL__native_file_optional(void *obj, hid_t H5_ATTR_UNUSED dxpl_id, void H5_ATTR
                 break;
             }
 
-        /* H5Iget_file_id */
-        case H5VL_NATIVE_FILE_GET_FILE_ID:
-            {
-                H5I_type_t  type = (H5I_type_t)HDva_arg(arguments, int); /* enum work-around */
-                hbool_t     app_ref = (hbool_t)HDva_arg(arguments, int);
-                hid_t      *file_id = HDva_arg(arguments, hid_t *);
-
-                if(NULL == (f = H5F__get_file(obj, type)))
-                    HGOTO_ERROR(H5E_FILE, H5E_BADTYPE, FAIL, "not a file or file object")
-                if((*file_id = H5F__get_file_id(f, app_ref)) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get file ID")
-                break;
-            }
-
         /* H5Fclear_elink_file_cache */
         case H5VL_NATIVE_FILE_CLEAR_ELINK_CACHE:
             {
diff --git a/src/H5VLnative_object.c b/src/H5VLnative_object.c
index 675d8cf..6a22b05 100644
--- a/src/H5VLnative_object.c
+++ b/src/H5VLnative_object.c
@@ -16,10 +16,11 @@
  */
 
 #define H5O_FRIEND              /* Suppress error about including H5Opkg    */
+#define H5F_FRIEND              /* Suppress error about including H5Fpkg    */
 
 #include "H5private.h"          /* Generic Functions                        */
 #include "H5Eprivate.h"         /* Error handling                           */
-#include "H5Fprivate.h"         /* Files                                    */
+#include "H5Fpkg.h"             /* Files (pkg needed for id_exists)         */
 #include "H5Gprivate.h"         /* Groups                                   */
 #include "H5Iprivate.h"         /* IDs                                      */
 #include "H5Opkg.h"             /* Object headers                           */
@@ -150,6 +151,25 @@ H5VL__native_object_get(void *obj, const H5VL_loc_params_t *loc_params, H5VL_obj
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
 
     switch(get_type) {
+
+        /* Object file */
+        case H5VL_OBJECT_GET_FILE:
+            {
+                void **ret = HDva_arg(arguments, void **);
+
+                if(loc_params->type == H5VL_OBJECT_BY_SELF) {
+                    *ret = (void *)loc.oloc->file;
+
+                    /* TODO we currently need to set id_exists to TRUE because
+                     * the upper layer will create an ID from the returned
+                     * object. In theory this should not be needed and id_exists
+                     * should be removed once the H5Fmount code gets fixed. */
+                    loc.oloc->file->id_exists = TRUE;
+                } else
+                    HGOTO_ERROR(H5E_VOL, H5E_UNSUPPORTED, FAIL, "unknown get_file parameters")
+                break;
+            }
+
         /* Object name */
         case H5VL_OBJECT_GET_NAME:
             {
@@ -267,7 +287,7 @@ H5VL__native_object_specific(void *obj, const H5VL_loc_params_t *loc_params, H5V
         /* Lookup object */
         case H5VL_OBJECT_LOOKUP:
             {
-                void *token = va_arg(arguments, void *);
+                H5VL_token_t *token = va_arg(arguments, H5VL_token_t *);
 
                 HDassert(token);
 
diff --git a/src/H5private.h b/src/H5private.h
index 2b35bd4..c39c946 100644
--- a/src/H5private.h
+++ b/src/H5private.h
@@ -521,13 +521,6 @@
 #   define H5_POSIX_CREATE_MODE_RW      0666
 #endif
 
-/*
- * A macro to portably increment enumerated types.
- */
-#ifndef H5_INC_ENUM
-#  define H5_INC_ENUM(TYPE,VAR) (VAR)=((TYPE)((VAR)+1))
-#endif
-
 /* Represents an empty asynchronous request handle.
  * Used in the VOL code.
  */
diff --git a/src/H5trace.c b/src/H5trace.c
index 79dfbc8..65e267e 100644
--- a/src/H5trace.c
+++ b/src/H5trace.c
@@ -3000,6 +3000,9 @@ H5_trace(const double *returning, const char *func, const char *type, ...)
                             H5VL_object_get_t get = (H5VL_object_get_t)HDva_arg(ap, int);
 
                             switch(get) {
+                                case H5VL_OBJECT_GET_FILE:
+                                    HDfprintf(out, "H5VL_OBJECT_GET_FILE");
+                                    break;
                                 case H5VL_OBJECT_GET_NAME:
                                     HDfprintf(out, "H5VL_OBJECT_GET_NAME");
                                     break;
diff --git a/src/hdf5-lin.lnt b/src/hdf5-lin.lnt
index da20937..23ceed2 100644
--- a/src/hdf5-lin.lnt
+++ b/src/hdf5-lin.lnt
@@ -13,9 +13,6 @@
 // Turn off warnings about not using the return value from these functions:
 -emacro(534,HDfflush,HDgetrusage,HDgettimeofday,HDputc)
 
-// Turn off warnings about converting an enum to an int
--emacro(641,H5_INC_ENUM,H5_DEC_ENUM)
-
 // Suppress message about "Expression with side effects passed to repeated parameter 1 in macro 'assert'"
 -esym(666,assert)
 
diff --git a/src/hdf5.lnt b/src/hdf5.lnt
index 642698a..995e3f6 100644
--- a/src/hdf5.lnt
+++ b/src/hdf5.lnt
@@ -30,11 +30,6 @@
 -esym(534, H5UC_decr)
 -esym(534, H5VM_array_fill)
 
-
-// Turn off warnings about "Expression-like macro not parenthesized" for
-// enumerated type increment & decrement macros:
--esym(773, H5_INC_ENUM, H5_DEC_ENUM)
-
 /* So far, the following files have been linted with these options:
         H5.c
         H5A.c
@@ -60,7 +55,7 @@
         H5FO.c
 
         H5Tcommit.c
-	H5Tcompound.c
+        H5Tcompound.c
 
         H5Tcset.c
         H5Tenum.c
diff --git a/src/libhdf5.settings.in b/src/libhdf5.settings.in
index 0c2be75..1591bed 100644
--- a/src/libhdf5.settings.in
+++ b/src/libhdf5.settings.in
@@ -39,7 +39,7 @@ Languages:
                     H5_CPPFLAGS: @H5_CPPFLAGS@
                     AM_CPPFLAGS: @AM_CPPFLAGS@
                         C Flags: @CFLAGS@
-                     H5 C Flags: @H5_CFLAGS@ @H5_ECFLAGS@
+                     H5 C Flags: @H5_CFLAGS@
                      AM C Flags: @AM_CFLAGS@
                Shared C Library: @enable_shared@
                Static C Library: @enable_static@