Fix for HDFFV-7853 H5Ocopy doesn't work with open identifiers

Changes made so that raw data for dataset objects are copied from cached info when possible instead of flushing objects to file and read them back in again.

6 files changed, 630 insertions, 205 deletions

diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index 33fc036..d693466 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -188,6 +188,10 @@ typedef struct H5D_chunk_it_ud3_t {
 
     /* needed for copy object pointed by refs */
     H5O_copy_t          *cpy_info;              /* Copy options */
+
+    /* needed for getting raw data from chunk cache */
+    hbool_t             chunk_in_cache;
+    uint8_t	            *chunk;		                /* the unfiltered chunk data		*/
 } H5D_chunk_it_ud3_t;
 
 /* Callback info for iteration to dump index */
@@ -2280,8 +2284,8 @@ H5D__chunk_read(H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
             void *chunk = NULL;             /* Pointer to locked chunk buffer */
             htri_t cacheable;               /* Whether the chunk is cacheable */
 
-	    /* Set chunk's [scaled] coordinates */
-	    io_info->store->chunk.scaled = chunk_info->scaled;
+            /* Set chunk's [scaled] coordinates */
+            io_info->store->chunk.scaled = chunk_info->scaled;
 
             /* Determine if we should use the chunk cache */
             if((cacheable = H5D__chunk_cacheable(io_info, udata.chunk_block.offset, FALSE)) < 0)
@@ -2796,7 +2800,7 @@ H5D__chunk_cinfo_cache_found(const H5D_chunk_cached_t *last, H5D_chunk_ud_t *uda
         /* Retrieve the information from the cache */
         udata->chunk_block.offset = last->addr;
         udata->chunk_block.length = last->nbytes;
-	udata->chunk_idx = last->chunk_idx;
+        udata->chunk_idx = last->chunk_idx;
         udata->filter_mask = last->filter_mask;
 
         /* Indicate that the data was found */
@@ -3065,19 +3069,19 @@ H5D__chunk_flush_entry(const H5D_t *dset, hid_t dxpl_id, const H5D_dxpl_cache_t
 
     buf = ent->chunk;
     if(ent->dirty) {
-	H5D_chk_idx_info_t idx_info;    /* Chunked index info */
+        H5D_chk_idx_info_t idx_info;    /* Chunked index info */
         H5D_chunk_ud_t 	udata;		/* pass through B-tree		*/
         hbool_t must_alloc = FALSE;     /* Whether the chunk must be allocated */
-	hbool_t need_insert = FALSE;    /* Whether the chunk needs to be inserted into the index */
+        hbool_t need_insert = FALSE;    /* Whether the chunk needs to be inserted into the index */
 
         /* Set up user data for index callbacks */
         udata.common.layout = &dset->shared->layout.u.chunk;
         udata.common.storage = &dset->shared->layout.storage.u.chunk;
-	udata.common.scaled = ent->scaled;
+        udata.common.scaled = ent->scaled;
         udata.chunk_block.offset = ent->chunk_block.offset;
         udata.chunk_block.length = dset->shared->layout.u.chunk.size;
         udata.filter_mask = 0;
-	udata.chunk_idx = ent->chunk_idx;
+        udata.chunk_idx = ent->chunk_idx;
 
         /* Should the chunk be filtered before writing it to disk? */
         if(dset->shared->dcpl_cache.pline.nused
@@ -3155,8 +3159,8 @@ H5D__chunk_flush_entry(const H5D_t *dset, hid_t dxpl_id, const H5D_dxpl_cache_t
             /* Create the chunk it if it doesn't exist, or reallocate the chunk
              *  if its size changed.
              */
-	    if(H5D__chunk_file_alloc(&idx_info, &(ent->chunk_block), &udata.chunk_block, &need_insert, ent->scaled) < 0)
-		HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL, "unable to insert/resize chunk on chunk level")
+            if(H5D__chunk_file_alloc(&idx_info, &(ent->chunk_block), &udata.chunk_block, &need_insert, ent->scaled) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL, "unable to insert/resize chunk on chunk level")
 
             /* Update the chunk entry's info, in case it was allocated or relocated */
             ent->chunk_block.offset = udata.chunk_block.offset;
@@ -3170,7 +3174,7 @@ H5D__chunk_flush_entry(const H5D_t *dset, hid_t dxpl_id, const H5D_dxpl_cache_t
             HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to write raw data to file")
 
         /* Insert the chunk record into the index */
-	if(need_insert && dset->shared->layout.storage.u.chunk.ops->insert)
+        if(need_insert && dset->shared->layout.storage.u.chunk.ops->insert)
             if((dset->shared->layout.storage.u.chunk.ops->insert)(&idx_info, &udata, dset) < 0)
                 HGOTO_ERROR(H5E_DATASET, H5E_CANTINSERT, FAIL, "unable to insert chunk addr into index")
 
@@ -3644,7 +3648,7 @@ H5D__chunk_lock(const H5D_io_info_t *io_info, H5D_chunk_ud_t *udata,
                 if(H5F_block_read(dset->oloc.file, H5FD_MEM_DRAW, chunk_addr, my_chunk_alloc, io_info->raw_dxpl_id, chunk) < 0)
                     HGOTO_ERROR(H5E_IO, H5E_READERROR, NULL, "unable to read raw data chunk")
 
-		if(old_pline && old_pline->nused) {
+                if(old_pline && old_pline->nused) {
                     if(H5Z_pipeline(old_pline, H5Z_FLAG_REVERSE,
                             &(udata->filter_mask),
                             io_info->dxpl_cache->err_detect,
@@ -3733,14 +3737,14 @@ H5D__chunk_lock(const H5D_io_info_t *io_info, H5D_chunk_ud_t *udata,
                 if(NULL == (ent = H5FL_CALLOC(H5D_rdcc_ent_t)))
                     HGOTO_ERROR(H5E_DATASET, H5E_CANTALLOC, NULL, "can't allocate raw data chunk entry")
 
-		ent->edge_chunk_state = disable_filters ? H5D_RDCC_DISABLE_FILTERS : 0;
-		if(udata->new_unfilt_chunk)
-		    ent->edge_chunk_state |= H5D_RDCC_NEWLY_DISABLED_FILTERS;
+                ent->edge_chunk_state = disable_filters ? H5D_RDCC_DISABLE_FILTERS : 0;
+                if(udata->new_unfilt_chunk)
+                    ent->edge_chunk_state |= H5D_RDCC_NEWLY_DISABLED_FILTERS;
 
                 /* Initialize the new entry */
                 ent->chunk_block.offset = chunk_addr;
                 ent->chunk_block.length = chunk_alloc;
-		ent->chunk_idx = udata->chunk_idx;
+                ent->chunk_idx = udata->chunk_idx;
                 HDmemcpy(ent->scaled, udata->common.scaled, sizeof(hsize_t) * layout->u.chunk.ndims);
                 H5_CHECKED_ASSIGN(ent->rd_count, uint32_t, chunk_size, size_t);
                 H5_CHECKED_ASSIGN(ent->wr_count, uint32_t, chunk_size, size_t);
@@ -3761,8 +3765,8 @@ H5D__chunk_lock(const H5D_io_info_t *io_info, H5D_chunk_ud_t *udata,
                 } /* end if */
                 else
                     rdcc->head = rdcc->tail = ent;
-		ent->tmp_next = NULL;
-		ent->tmp_prev = NULL;
+                ent->tmp_next = NULL;
+                ent->tmp_prev = NULL;
 
             } /* end if */
             else
@@ -5658,11 +5662,22 @@ H5D__chunk_copy_cb(const H5D_chunk_rec_t *chunk_rec, void *_udata)
     H5Z_cb_t                cb_struct;                  /* Filter failure callback struct */
     int                     ret_value = H5_ITER_CONT;   /* Return value */
 
+
     FUNC_ENTER_STATIC
 
     /* Get 'size_t' local value for number of bytes in chunk */
     H5_CHECKED_ASSIGN(nbytes, size_t, chunk_rec->nbytes, uint32_t);
 
+    /* Check for filtered chunks */
+    /* Check for an edge chunk that is not filtered */
+    if(pline && pline->nused) {
+        must_filter = TRUE;
+        if( (udata->common.layout->flags & H5O_LAYOUT_CHUNK_DONT_FILTER_PARTIAL_BOUND_CHUNKS) &&
+            (H5D__chunk_is_partial_edge_chunk(udata->dset_ndims, udata->common.layout->dim, 
+                                              chunk_rec->scaled, udata->dset_dims)) )
+            must_filter = FALSE;
+    }
+
     /* Check parameter for type conversion */
     if(udata->do_convert) {
         if(H5T_detect_class(udata->dt_src, H5T_VLEN, FALSE) > 0)
@@ -5673,19 +5688,6 @@ H5D__chunk_copy_cb(const H5D_chunk_rec_t *chunk_rec, void *_udata)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTCOPY, H5_ITER_ERROR, "unable to copy dataset elements")
     } /* end if */
 
-    /* Check for filtered chunks */
-    if((is_vlen || fix_ref) && pline && pline->nused) {
-        /* Check if we should disable filters on this chunk */
-        if(udata->common.layout->flags
-                & H5O_LAYOUT_CHUNK_DONT_FILTER_PARTIAL_BOUND_CHUNKS) {
-            /* Check if the chunk is an edge chunk, and disable filters if so */
-            if(!H5D__chunk_is_partial_edge_chunk(udata->dset_ndims, udata->common.layout->dim, chunk_rec->scaled, udata->dset_dims))
-                must_filter = TRUE;
-        } /* end if */
-        else
-            must_filter = TRUE;
-    } /* end if */
-
     /* Resize the buf if it is too small to hold the data */
     if(nbytes > buf_size) {
         void *new_buf;          /* New buffer for data */
@@ -5708,12 +5710,51 @@ H5D__chunk_copy_cb(const H5D_chunk_rec_t *chunk_rec, void *_udata)
         udata->buf_size = buf_size = nbytes;
     } /* end if */
 
-    /* read chunk data from the source file */
-    if(H5F_block_read(udata->file_src, H5FD_MEM_DRAW, chunk_rec->chunk_addr, nbytes, H5AC_rawdata_dxpl_id, buf) < 0)
-        HGOTO_ERROR(H5E_IO, H5E_READERROR, H5_ITER_ERROR, "unable to read raw data chunk")
+    if(udata->chunk_in_cache && udata->chunk) {
+        HDassert(!H5F_addr_defined(chunk_rec->chunk_addr));
+        HDmemcpy(buf, udata->chunk, nbytes);
+        udata->chunk = NULL;
+    } else {
+        H5D_rdcc_ent_t *ent = NULL;    /* Cache entry */
+        unsigned idx;                   /* Index of chunk in cache, if present */
+        unsigned u;                     /* Counter */
+        H5D_shared_t *shared_fo = udata->cpy_info->shared_fo;
+
+        /* See if the written chunk is in the chunk cache */
+        if(shared_fo && shared_fo->cache.chunk.nslots > 0) {
+            /* Determine the chunk's location in the hash table */
+            idx = H5D__chunk_hash_val(shared_fo, chunk_rec->scaled);
+
+            /* Get the chunk cache entry for that location */
+            ent = shared_fo->cache.chunk.slot[idx];
+            if(ent) {
+                /* Speculatively set the 'found' flag */
+                udata->chunk_in_cache = TRUE;
+
+                /* Verify that the cache entry is the correct chunk */
+                for(u = 0; u < shared_fo->ndims; u++)
+                    if(chunk_rec->scaled[u] != ent->scaled[u]) {
+                        udata->chunk_in_cache = FALSE;
+                        break;
+                    } /* end if */
+            } /* end if */
+        } /* end if */
+
+        if(udata->chunk_in_cache) {
+            HDassert(H5F_addr_defined(chunk_rec->chunk_addr));
+            HDassert(H5F_addr_defined(ent->chunk_block.offset));
+
+            H5_CHECKED_ASSIGN(nbytes, size_t, shared_fo->layout.u.chunk.size, uint32_t);
+            HDmemcpy(buf, ent->chunk, nbytes);
+        } else {
+            /* read chunk data from the source file */
+            if(H5F_block_read(udata->file_src, H5FD_MEM_DRAW, chunk_rec->chunk_addr, nbytes, H5AC_rawdata_dxpl_id, buf) < 0)
+                HGOTO_ERROR(H5E_IO, H5E_READERROR, H5_ITER_ERROR, "unable to read raw data chunk")
+        }
+    }
 
-    /* Need to uncompress variable-length & reference data elements */
-    if(must_filter) {
+    /* Need to uncompress filtered variable-length & reference data elements that are not found in chunk cache */
+    if(must_filter && (is_vlen || fix_ref) && !udata->chunk_in_cache) {
         unsigned filter_mask = chunk_rec->filter_mask;
 
         cb_struct.func = NULL; /* no callback function when failed */
@@ -5777,8 +5818,8 @@ H5D__chunk_copy_cb(const H5D_chunk_rec_t *chunk_rec, void *_udata)
     udata_dst.chunk_block.length = chunk_rec->nbytes;
     udata_dst.filter_mask = chunk_rec->filter_mask;
 
-    /* Need to compress variable-length & reference data elements before writing to file */
-    if(must_filter) {
+    /* Need to compress variable-length or reference data elements or a chunk found in cache before writing to file */
+    if(must_filter && (is_vlen || fix_ref || udata->chunk_in_cache) ) {
         if(H5Z_pipeline(pline, 0, &(udata_dst.filter_mask), H5Z_NO_EDC, cb_struct, &nbytes, &buf_size, &buf) < 0)
             HGOTO_ERROR(H5E_PLINE, H5E_CANTFILTER, H5_ITER_ERROR, "output pipeline failed")
 #if H5_SIZEOF_SIZE_T > 4
@@ -5787,12 +5828,14 @@ H5D__chunk_copy_cb(const H5D_chunk_rec_t *chunk_rec, void *_udata)
             HGOTO_ERROR(H5E_DATASET, H5E_BADRANGE, H5_ITER_ERROR, "chunk too large for 32-bit length")
 #endif /* H5_SIZEOF_SIZE_T > 4 */
         H5_CHECKED_ASSIGN(udata_dst.chunk_block.length, uint32_t, nbytes, size_t);
-	udata->buf = buf;
-	udata->buf_size = buf_size;
+        udata->buf = buf;
+        udata->buf_size = buf_size;
     } /* end if */
 
+    udata->chunk_in_cache = FALSE;
+
     udata_dst.chunk_idx = H5VM_array_offset_pre(udata_dst.common.layout->ndims - 1, 
-			    udata_dst.common.layout->max_down_chunks, udata_dst.common.scaled);
+	udata_dst.common.layout->max_down_chunks, udata_dst.common.scaled);
 
     /* Allocate chunk in the file */
     if(H5D__chunk_file_alloc(udata->idx_info_dst, NULL, &udata_dst.chunk_block, &need_insert, udata_dst.common.scaled) < 0)
@@ -6047,11 +6090,35 @@ H5D__chunk_copy(H5F_t *f_src, H5O_storage_chunk_t *storage_src,
     udata.dset_ndims = (unsigned)sndims;
     udata.dset_dims = curr_dims;
     udata.cpy_info = cpy_info;
+    udata.chunk_in_cache = FALSE;
+    udata.chunk = NULL;
 
     /* Iterate over chunks to copy data */
     if((storage_src->ops->iterate)(&idx_info_src, H5D__chunk_copy_cb, &udata) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_BADITER, FAIL, "unable to iterate over chunk index to copy data")
 
+    /* Iterate over the chunk cache to copy data for chunks with undefined address */
+    if(udata.cpy_info->shared_fo) {
+        H5D_rdcc_ent_t  *ent, *next;
+        H5D_chunk_rec_t chunk_rec;
+        H5D_shared_t *shared_fo = (H5D_shared_t *)udata.cpy_info->shared_fo;
+
+        chunk_rec.nbytes = layout_src->size;
+        chunk_rec.filter_mask = 0;
+        chunk_rec.chunk_addr = HADDR_UNDEF;
+
+        for(ent = shared_fo->cache.chunk.head; ent; ent = next) {
+            if(!H5F_addr_defined(ent->chunk_block.offset)) {
+                HDmemcpy(chunk_rec.scaled, ent->scaled, sizeof(chunk_rec.scaled));
+                udata.chunk = ent->chunk;
+                udata.chunk_in_cache = TRUE;
+                if(H5D__chunk_copy_cb(&chunk_rec, &udata) < 0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTCOPY, FAIL, "unable to copy chunk data in cache")
+            }
+            next = ent->next;
+        } /* end for */
+    }
+
     /* I/O buffers may have been re-allocated */
     buf = udata.buf;
     bkg = udata.bkg;
diff --git a/src/H5Dcompact.c b/src/H5Dcompact.c
index 99a25b6..041d28f 100644
--- a/src/H5Dcompact.c
+++ b/src/H5Dcompact.c
@@ -420,7 +420,7 @@ H5D__compact_dest(H5D_t *dset, hid_t H5_ATTR_UNUSED dxpl_id)
  *-------------------------------------------------------------------------
  */
 herr_t
-H5D__compact_copy(H5F_t *f_src, H5O_storage_compact_t *storage_src, H5F_t *f_dst,
+H5D__compact_copy(H5F_t *f_src, H5O_storage_compact_t *_storage_src, H5F_t *f_dst,
     H5O_storage_compact_t *storage_dst, H5T_t *dt_src, H5O_copy_t *cpy_info,
     hid_t dxpl_id)
 {
@@ -431,6 +431,8 @@ H5D__compact_copy(H5F_t *f_src, H5O_storage_compact_t *storage_src, H5F_t *f_dst
     void       *bkg = NULL;             /* Temporary buffer for copying data */
     void       *reclaim_buf = NULL;     /* Buffer for reclaiming data */
     hid_t       buf_sid = -1;           /* ID for buffer dataspace */
+    H5D_shared_t    *shared_fo = cpy_info->shared_fo;   /* Pointer to the shared struct for dataset object */
+    H5O_storage_compact_t *storage_src = _storage_src;  /* Pointer to storage_src */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_PACKAGE
@@ -443,6 +445,10 @@ H5D__compact_copy(H5F_t *f_src, H5O_storage_compact_t *storage_src, H5F_t *f_dst
     HDassert(storage_dst->buf);
     HDassert(dt_src);
 
+    /* If the dataset is open in the file, point to "layout" in the shared struct */
+    if(shared_fo != NULL)
+        storage_src = &(shared_fo->layout.storage.u.compact);
+
     /* Create datatype ID for src datatype, so it gets freed */
     if((tid_src = H5I_register(H5I_DATATYPE, dt_src, FALSE)) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTREGISTER, FAIL, "unable to register source file datatype")
diff --git a/src/H5Dcontig.c b/src/H5Dcontig.c
index 0ee4d28..86de017 100644
--- a/src/H5Dcontig.c
+++ b/src/H5Dcontig.c
@@ -31,17 +31,18 @@
 /***********/
 /* Headers */
 /***********/
-#include "H5private.h"		/* Generic Functions			*/
-#include "H5Dpkg.h"		/* Dataset functions			*/
-#include "H5Eprivate.h"		/* Error handling		  	*/
-#include "H5Fprivate.h"		/* Files				*/
-#include "H5FDprivate.h"	/* File drivers				*/
-#include "H5FLprivate.h"	/* Free Lists                           */
-#include "H5Iprivate.h"		/* IDs			  		*/
-#include "H5MFprivate.h"	/* File memory management		*/
-#include "H5Oprivate.h"		/* Object headers		  	*/
-#include "H5Pprivate.h"		/* Property lists			*/
-#include "H5VMprivate.h"		/* Vector and array functions		*/
+#include "H5private.h"      /* Generic Functions            */
+#include "H5Dpkg.h"         /* Dataset functions            */
+#include "H5Eprivate.h"     /* Error handling               */
+#include "H5Fprivate.h"     /* Files                        */
+#include "H5FDprivate.h"    /* File drivers                 */
+#include "H5FLprivate.h"    /* Free Lists                   */
+#include "H5Iprivate.h"     /* IDs                          */
+#include "H5MFprivate.h"    /* File memory management       */
+#include "H5FOprivate.h"    /* File objects                 */
+#include "H5Oprivate.h"     /* Object headers               */
+#include "H5Pprivate.h"     /* Property lists               */
+#include "H5VMprivate.h"    /* Vector and array functions   */
 
 
 /****************/
@@ -1362,6 +1363,10 @@ H5D__contig_copy(H5F_t *f_src, const H5O_storage_contig_t *storage_src,
     hsize_t     buf_dim[1] = {0};       /* Dimension for buffer */
     hbool_t     is_vlen = FALSE;        /* Flag to indicate that VL type conversion should occur */
     hbool_t     fix_ref = FALSE;        /* Flag to indicate that ref values should be fixed */
+    H5D_shared_t    *shared_fo = cpy_info->shared_fo;  /* Pointer to the shared struct for dataset object */
+    hbool_t     try_sieve = FALSE;      /* Try to get data from the sieve buffer */
+    haddr_t     sieve_start = HADDR_UNDEF; /* Start location of sieve buffer */
+    haddr_t     sieve_end = HADDR_UNDEF;    /* End locations of sieve buffer */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_PACKAGE
@@ -1485,6 +1490,16 @@ H5D__contig_copy(H5F_t *f_src, const H5O_storage_contig_t *storage_src,
     /* Loop over copying data */
     addr_src = storage_src->addr;
     addr_dst = storage_dst->addr;
+
+    /* If data sieving is enabled and the dataset is open in the file,
+       set up to copy data out of the sieve buffer if deemed possible later */
+    if(H5F_HAS_FEATURE(f_src, H5FD_FEAT_DATA_SIEVE) &&
+       shared_fo && shared_fo->cache.contig.sieve_buf) {
+        try_sieve = TRUE;
+        sieve_start = shared_fo->cache.contig.sieve_loc;
+        sieve_end = sieve_start + shared_fo->cache.contig.sieve_size;
+    }
+
     while(total_src_nbytes > 0) {
         /* Check if we should reduce the number of bytes to transfer */
         if(total_src_nbytes < src_nbytes) {
@@ -1510,14 +1525,20 @@ H5D__contig_copy(H5F_t *f_src, const H5O_storage_contig_t *storage_src,
                 dst_nbytes = mem_nbytes = src_nbytes;
         } /* end if */
 
-        /* Read raw data from source file - use raw dxpl because passed in one is metadata */
-        if(H5F_block_read(f_src, H5FD_MEM_DRAW, addr_src, src_nbytes, H5AC_rawdata_dxpl_id, buf) < 0)
-            HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "unable to read raw data")
+        /* If the entire copy is within the sieve buffer, copy data from the sieve buffer */
+        if(try_sieve && (addr_src >= sieve_start) && ((addr_src + src_nbytes -1) < sieve_end)) {
+            unsigned char *base_sieve_buf = shared_fo->cache.contig.sieve_buf + (addr_src - sieve_start);
+
+            HDmemcpy(buf, base_sieve_buf, src_nbytes);
+        } else
+            /* Read raw data from source file - use raw dxpl because passed in one is metadata */
+            if(H5F_block_read(f_src, H5FD_MEM_DRAW, addr_src, src_nbytes, H5AC_rawdata_dxpl_id, buf) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "unable to read raw data")
 
         /* Perform datatype conversion, if necessary */
         if(is_vlen) {
             /* Convert from source file to memory */
-	    if(H5T_convert(tpath_src_mem, tid_src, tid_mem, nelmts, (size_t)0, (size_t)0, buf, bkg, dxpl_id) < 0)
+            if(H5T_convert(tpath_src_mem, tid_src, tid_mem, nelmts, (size_t)0, (size_t)0, buf, bkg, dxpl_id) < 0)
                 HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "datatype conversion failed")
 
             /* Copy into another buffer, to reclaim memory later */
@@ -1527,13 +1548,13 @@ H5D__contig_copy(H5F_t *f_src, const H5O_storage_contig_t *storage_src,
             HDmemset(bkg, 0, buf_size);
 
             /* Convert from memory to destination file */
-	    if(H5T_convert(tpath_mem_dst, tid_mem, tid_dst, nelmts, (size_t)0, (size_t)0, buf, bkg, dxpl_id) < 0)
+            if(H5T_convert(tpath_mem_dst, tid_mem, tid_dst, nelmts, (size_t)0, (size_t)0, buf, bkg, dxpl_id) < 0)
                 HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "datatype conversion failed")
 
             /* Reclaim space from variable length data */
             if(H5D_vlen_reclaim(tid_mem, buf_space, dxpl_id, reclaim_buf) < 0)
                 HGOTO_ERROR(H5E_DATASET, H5E_BADITER, FAIL, "unable to reclaim variable-length data")
-	} /* end if */
+        } /* end if */
         else if(fix_ref) {
             /* Check for expanding references */
             if(cpy_info->expand_ref) {
diff --git a/src/H5Ocopy.c b/src/H5Ocopy.c
index 597af63..aa2a9e0 100644
--- a/src/H5Ocopy.c
+++ b/src/H5Ocopy.c
@@ -347,36 +347,8 @@ H5O_copy_header_real(const H5O_loc_t *oloc_src, H5O_loc_t *oloc_dst /*out*/,
     if(NULL == (obj_class = H5O_obj_class(oloc_src, dxpl_id)))
         HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "unable to determine object type")
 
-    /* Check if the object at the address is already open in the file */
-    if(H5FO_opened(oloc_src->file, oloc_src->addr) != NULL) {
-	H5G_loc_t   tmp_loc; 	/* Location of object */
-	H5O_loc_t   tmp_oloc; 	/* Location of object */
-	H5G_name_t  tmp_path;	/* Object's path */
-	void *obj_ptr = NULL;	/* Object pointer */
-	hid_t tmp_id = -1;	/* Object ID */
-
-	tmp_loc.oloc = &tmp_oloc;
-	tmp_loc.path = &tmp_path;
-	tmp_oloc.file = oloc_src->file;
-	tmp_oloc.addr = oloc_src->addr;
-	tmp_oloc.holding_file = FALSE;
-	H5G_name_reset(tmp_loc.path);
-
-	/* Get a temporary ID */
-	if((tmp_id = obj_class->open(&tmp_loc, H5P_DEFAULT, dxpl_id, FALSE)) < 0)
-            HGOTO_ERROR(H5E_OHDR, H5E_CANTFLUSH, FAIL, "unable to open object")
-
-	/* Get object pointer */
-	obj_ptr = H5I_object(tmp_id);
-
-	/* Flush the object */
-        if(obj_class->flush && obj_class->flush(obj_ptr, dxpl_id) < 0)
-            HGOTO_ERROR(H5E_OHDR, H5E_CANTFLUSH, FAIL, "unable to flush object")
-
-	/* Release the temporary ID */
-	if(tmp_id != -1 && H5I_dec_app_ref(tmp_id))
-	    HGOTO_ERROR(H5E_OHDR, H5E_CANTRELEASE, FAIL, "unable to close temporary ID")
-    } /* end if */
+    /* Set the pointer to the shared struct for the object if opened in the file */
+    cpy_info->shared_fo = H5FO_opened(oloc_src->file, oloc_src->addr);
 
     /* Get source object header */
     if(NULL == (oh_src = H5O_protect(oloc_src, dxpl_id, H5AC__READ_ONLY_FLAG, FALSE)))
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 0f798b2..563f8fa 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -174,6 +174,7 @@ typedef struct H5O_copy_t {
     H5SL_t  *dst_dt_list;               /* Skip list to hold committed datatypes in dest file */
     hbool_t dst_dt_list_complete;       /* Whether the destination datatype list is complete (i.e. not only populated with "suggestions" from H5Padd_merge_committed_dtype_path) */
     H5O_t   *oh_dst;                    /* The destination object header */
+    void    *shared_fo;                 /* The shared pointer for the object */
     H5O_mcdt_search_cb_t mcdt_cb;	/* The callback to invoke before searching the global list of committed datatypes at destination */
     void *mcdt_ud;			/* User data passed to callback */
 } H5O_copy_t;
diff --git a/test/objcopy.c b/test/objcopy.c
index b7f5673..216d111 100644
--- a/test/objcopy.c
+++ b/test/objcopy.c
@@ -2200,6 +2200,9 @@ error:
  * Purpose:     Create a simple dataset in SRC file and copy it to DST file
  *              (Note: dataset has no data)
  *
+ *              Note: The parameter "test_open" is added to test for H5Ocopy when 
+ *                    the dataset is open in the file (HDFFV-7853).
+ *
  * Return:      Success:        0
  *              Failure:        number of errors
  *
@@ -2209,7 +2212,7 @@ error:
  *-------------------------------------------------------------------------
  */
 static int
-test_copy_dataset_simple_empty(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl)
+test_copy_dataset_simple_empty(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl, hbool_t test_open)
 {
     hid_t fid_src = -1, fid_dst = -1;           /* File IDs */
     hid_t sid = -1;                             /* Dataspace ID */
@@ -2218,7 +2221,11 @@ test_copy_dataset_simple_empty(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, h
     char src_filename[NAME_BUF_SIZE];
     char dst_filename[NAME_BUF_SIZE];
 
-    TESTING("H5Ocopy(): empty contiguous dataset");
+    if(test_open) {
+        TESTING("H5Ocopy(): empty and openend contiguous dataset");
+    } else {
+        TESTING("H5Ocopy(): empty contiguous dataset");
+    }
 
     /* Initialize the filenames */
     h5_fixname(FILENAME[0], src_fapl, src_filename, sizeof src_filename);
@@ -2246,15 +2253,18 @@ test_copy_dataset_simple_empty(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, h
     /* attach attributes to the dataset */
     if(test_copy_attach_attributes(did, H5T_NATIVE_INT) < 0) TEST_ERROR
 
-    /* close the dataset */
-    if(H5Dclose(did) < 0) TEST_ERROR
+    if(!test_open) {
 
-    /* close the SRC file */
-    if(H5Fclose(fid_src) < 0) TEST_ERROR
+        /* close the dataset */
+        if(H5Dclose(did) < 0) TEST_ERROR
 
+        /* close the SRC file */
+        if(H5Fclose(fid_src) < 0) TEST_ERROR
 
-    /* open the source file with read-only */
-    if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+        /* open the source file with read-only */
+        if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+
+    }
 
     /* create destination file */
     if((fid_dst = H5Fcreate(dst_filename, H5F_ACC_TRUNC, fcpl_dst, dst_fapl)) < 0) TEST_ERROR
@@ -2265,8 +2275,10 @@ test_copy_dataset_simple_empty(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, h
     /* copy the dataset from SRC to DST */
     if(H5Ocopy(fid_src, NAME_DATASET_SIMPLE, fid_dst, NAME_DATASET_SIMPLE, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
-    /* open the dataset for copy */
-    if((did = H5Dopen2(fid_src, NAME_DATASET_SIMPLE, H5P_DEFAULT)) < 0) TEST_ERROR
+    if(!test_open) {
+        /* open the dataset for copy */
+        if((did = H5Dopen2(fid_src, NAME_DATASET_SIMPLE, H5P_DEFAULT)) < 0) TEST_ERROR
+    }
 
     /* open the destination dataset */
     if((did2 = H5Dopen2(fid_dst, NAME_DATASET_SIMPLE, H5P_DEFAULT)) < 0) TEST_ERROR
@@ -3890,6 +3902,9 @@ error:
  *
  * Purpose:     Create a compressed, chunked dataset in SRC file and copy it to DST file
  *
+ *              Note: The parameter "test_open" is added to test for H5Ocopy when 
+ *                    the dataset is open in the file (HDFFV-7853).
+ *
  * Return:      Success:        0
  *              Failure:        number of errors
  *
@@ -3902,7 +3917,7 @@ error:
  */
 static int
 test_copy_dataset_no_edge_filt(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl,
-    hid_t dst_fapl)
+    hid_t dst_fapl, hbool_t test_open)
 {
 #ifdef H5_HAVE_FILTER_DEFLATE
     hid_t fid_src = -1, fid_dst = -1;           /* File IDs */
@@ -3917,7 +3932,11 @@ test_copy_dataset_no_edge_filt(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl,
     char dst_filename[NAME_BUF_SIZE];
 #endif /* H5_HAVE_FILTER_DEFLATE */
 
-    TESTING("H5Ocopy(): compressed dataset with no edge filters");
+    if(test_open) {
+        TESTING("H5Ocopy(): compressed and opened dataset with no edge filters");
+    } else {
+        TESTING("H5Ocopy(): compressed dataset with no edge filters");
+    }
 
 #ifndef H5_HAVE_FILTER_DEFLATE
     SKIPPED();
@@ -3966,15 +3985,19 @@ test_copy_dataset_no_edge_filt(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl,
     /* attach attributes to the dataset */
     if(test_copy_attach_attributes(did, H5T_NATIVE_INT) < 0) TEST_ERROR
 
-    /* close the dataset */
-    if(H5Dclose(did) < 0) TEST_ERROR
+    if(!test_open) {
 
-    /* close the SRC file */
-    if(H5Fclose(fid_src) < 0) TEST_ERROR
+        /* close the dataset */
+        if(H5Dclose(did) < 0) TEST_ERROR
 
+        /* close the SRC file */
+        if(H5Fclose(fid_src) < 0) TEST_ERROR
 
-    /* open the source file with read-only */
-    if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+
+        /* open the source file with read-only */
+        if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+
+    }
 
     /* create destination file */
     if((fid_dst = H5Fcreate(dst_filename, H5F_ACC_TRUNC, fcpl_dst, dst_fapl)) < 0) TEST_ERROR
@@ -3985,8 +4008,10 @@ test_copy_dataset_no_edge_filt(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl,
     /* copy the dataset from SRC to DST */
     if(H5Ocopy(fid_src, NAME_DATASET_CHUNKED, fid_dst, NAME_DATASET_CHUNKED, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
-    /* open the dataset for copy */
-    if((did = H5Dopen2(fid_src, NAME_DATASET_CHUNKED, H5P_DEFAULT)) < 0) TEST_ERROR
+    if(!test_open) {
+        /* open the dataset for copy */
+        if((did = H5Dopen2(fid_src, NAME_DATASET_CHUNKED, H5P_DEFAULT)) < 0) TEST_ERROR
+    }
 
     /* open the destination dataset */
     if((did2 = H5Dopen2(fid_dst, NAME_DATASET_CHUNKED, H5P_DEFAULT)) < 0) TEST_ERROR
@@ -4034,6 +4059,9 @@ error:
  *
  * Purpose:     Create a compact dataset in SRC file and copy it to DST file
  *
+ *              Note: The parameter "test_open" is added to test for H5Ocopy when 
+ *                    the dataset is open in the file (HDFFV-7853).
+ *
  * Return:      Success:        0
  *              Failure:        number of errors
  *
@@ -4043,7 +4071,7 @@ error:
  *-------------------------------------------------------------------------
  */
 static int
-test_copy_dataset_compact(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl)
+test_copy_dataset_compact(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl, hbool_t test_open)
 {
     hid_t fid_src = -1, fid_dst = -1;           /* File IDs */
     hid_t sid = -1;                             /* Dataspace ID */
@@ -4055,7 +4083,11 @@ test_copy_dataset_compact(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t
     char src_filename[NAME_BUF_SIZE];
     char dst_filename[NAME_BUF_SIZE];
 
-    TESTING("H5Ocopy(): compact dataset");
+    if(test_open) {
+        TESTING("H5Ocopy(): compact and opened dataset");
+    } else {
+        TESTING("H5Ocopy(): compact dataset");
+    }
 
     /* set initial data values */
     for (i=0; i<DIM_SIZE_1; i++)
@@ -4098,15 +4130,17 @@ test_copy_dataset_compact(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t
     /* attach attributes to the dataset */
     if(test_copy_attach_attributes(did, H5T_NATIVE_INT) < 0) TEST_ERROR
 
-    /* close the dataset */
-    if(H5Dclose(did) < 0) TEST_ERROR
+    if(!test_open) {
+        /* close the dataset */
+        if(H5Dclose(did) < 0) TEST_ERROR
 
-    /* close the SRC file */
-    if(H5Fclose(fid_src) < 0) TEST_ERROR
+        /* close the SRC file */
+        if(H5Fclose(fid_src) < 0) TEST_ERROR
 
 
-    /* open the source file with read-only */
-    if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+        /* open the source file with read-only */
+        if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+    }
 
     /* create destination file */
     if((fid_dst = H5Fcreate(dst_filename, H5F_ACC_TRUNC, fcpl_dst, dst_fapl)) < 0) TEST_ERROR
@@ -4117,8 +4151,10 @@ test_copy_dataset_compact(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t
     /* copy the dataset from SRC to DST */
     if(H5Ocopy(fid_src, NAME_DATASET_COMPACT, fid_dst, NAME_DATASET_COMPACT, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
-    /* open the dataset for copy */
-    if((did = H5Dopen2(fid_src, NAME_DATASET_COMPACT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if(!test_open) {
+        /* open the dataset for copy */
+        if((did = H5Dopen2(fid_src, NAME_DATASET_COMPACT, H5P_DEFAULT)) < 0) TEST_ERROR
+    }
 
     /* open the destination dataset */
     if((did2 = H5Dopen2(fid_dst, NAME_DATASET_COMPACT, H5P_DEFAULT)) < 0) TEST_ERROR
@@ -4686,6 +4722,9 @@ error:
  *              creates lots of object header chunks in SRC file and copy
  *              datasets to DST file
  *
+ *              Note: The parameter "test_open" is added to test for H5Ocopy when
+ *                    the dataset is open in the file (HDFFV-7853).
+ *
  * Return:      Success:        0
  *              Failure:        number of errors
  *
@@ -4695,7 +4734,7 @@ error:
  *-------------------------------------------------------------------------
  */
 static int
-test_copy_dataset_multi_ohdr_chunks(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl)
+test_copy_dataset_multi_ohdr_chunks(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl, hbool_t test_open)
 {
     hid_t fid_src = -1, fid_dst = -1;           /* File IDs */
     hid_t sid = -1;                             /* Dataspace ID */
@@ -4707,7 +4746,11 @@ test_copy_dataset_multi_ohdr_chunks(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fa
     char src_filename[NAME_BUF_SIZE];
     char dst_filename[NAME_BUF_SIZE];
 
-    TESTING("H5Ocopy(): datasets that have multiple ohdr chunks");
+    if(test_open) {
+        TESTING("H5Ocopy(): opened datasets that have multiple ohdr chunks");
+    } else {
+        TESTING("H5Ocopy(): datasets that have multiple ohdr chunks");
+    }
 
     /* set initial data values */
     for (i=0; i<DIM_SIZE_1; i++)
@@ -4747,24 +4790,27 @@ test_copy_dataset_multi_ohdr_chunks(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fa
     /* Add attributes to datasets in a way that creates lots of chunks */
     if(test_copy_attach_paired_attributes(did, did2, H5T_NATIVE_INT) < 0) TEST_ERROR
 
+    /* close dataspace */
+    if(H5Sclose(sid) < 0) TEST_ERROR
+
     /* close the first dataset */
     if(H5Dclose(did) < 0) TEST_ERROR
 
-    /* close the second dataset */
-    if(H5Dclose(did2) < 0) TEST_ERROR
+    if(!test_open) {
 
-    /* close dataspace */
-    if(H5Sclose(sid) < 0) TEST_ERROR
+        /* close the second dataset */
+        if(H5Dclose(did2) < 0) TEST_ERROR
 
-    /* close group */
-    if(H5Gclose(gid) < 0) TEST_ERROR
+        /* close group */
+        if(H5Gclose(gid) < 0) TEST_ERROR
 
-    /* close the SRC file */
-    if(H5Fclose(fid_src) < 0) TEST_ERROR
+        /* close the SRC file */
+        if(H5Fclose(fid_src) < 0) TEST_ERROR
 
+        /* open the source file with read-only */
+        if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
 
-    /* open the source file with read-only */
-    if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+    }
 
     /* create destination file */
     if((fid_dst = H5Fcreate(dst_filename, H5F_ACC_TRUNC, fcpl_dst, dst_fapl)) < 0) TEST_ERROR
@@ -4775,8 +4821,13 @@ test_copy_dataset_multi_ohdr_chunks(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fa
     /* copy the dataset from SRC to DST */
     if(H5Ocopy(fid_src, NAME_GROUP_TOP, fid_dst, NAME_GROUP_TOP, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
-    /* open the group for copy */
-    if((gid = H5Gopen2(fid_src, NAME_GROUP_TOP, H5P_DEFAULT)) < 0) FAIL_STACK_ERROR
+    if(test_open) {
+        /* close the second dataset */
+        if(H5Dclose(did2) < 0) TEST_ERROR
+
+    } else 
+        /* open the group for copy */
+        if((gid = H5Gopen2(fid_src, NAME_GROUP_TOP, H5P_DEFAULT)) < 0) FAIL_STACK_ERROR
 
     /* open the destination group */
     if((gid2 = H5Gopen2(fid_dst, NAME_GROUP_TOP, H5P_DEFAULT)) < 0) FAIL_STACK_ERROR
@@ -7008,6 +7059,9 @@ error:
  * Purpose:     Create a soft link in SRC file and copy it to DST file
  *              copy a datast pointed by a soft link to DST file
  *
+ *              Note: The parameter "test_open" is added to test for H5Ocopy when
+ *                    the dataset is open in the file (HDFFV-7853).
+ *
  * Return:      Success:        0
  *              Failure:        number of errors
  *
@@ -7017,7 +7071,7 @@ error:
  *-------------------------------------------------------------------------
  */
 static int
-test_copy_soft_link(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl)
+test_copy_soft_link(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl, hbool_t test_open)
 {
     hid_t fid_src = -1, fid_dst = -1;           /* File IDs */
     hid_t sid = -1;                             /* Dataspace ID */
@@ -7029,7 +7083,11 @@ test_copy_soft_link(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fa
     char src_filename[NAME_BUF_SIZE];
     char dst_filename[NAME_BUF_SIZE];
 
-    TESTING("H5Ocopy(): object through soft link");
+    if(test_open) {
+        TESTING("H5Ocopy(): openend object through soft link");
+    } else {
+        TESTING("H5Ocopy(): object through soft link");
+    }
 
     /* set initial data values */
     for (i=0; i<DIM_SIZE_1; i++)
@@ -7066,21 +7124,22 @@ test_copy_soft_link(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fa
     /* close dataspace */
     if(H5Sclose(sid) < 0) FAIL_STACK_ERROR
 
-    /* close the dataset */
-    if(H5Dclose(did) < 0) FAIL_STACK_ERROR
+    /* close the group */
+    if(H5Gclose(gid) < 0) FAIL_STACK_ERROR
 
     /* make a soft link to the dataset */
     if(H5Lcreate_soft(NAME_LINK_DATASET, fid_src, NAME_LINK_SOFT, H5P_DEFAULT, H5P_DEFAULT) < 0) FAIL_STACK_ERROR
 
-    /* close the group */
-    if(H5Gclose(gid) < 0) FAIL_STACK_ERROR
+    if(!test_open) {
+        /* close the dataset */
+        if(H5Dclose(did) < 0) FAIL_STACK_ERROR
 
-    /* close the SRC file */
-    if(H5Fclose(fid_src) < 0) FAIL_STACK_ERROR
+        /* close the SRC file */
+        if(H5Fclose(fid_src) < 0) FAIL_STACK_ERROR
 
-
-    /* open the source file with read-only */
-    if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+        /* open the source file with read-only */
+        if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+    }
 
     /* create destination file */
     if((fid_dst = H5Fcreate(dst_filename, H5F_ACC_TRUNC, fcpl_dst, dst_fapl)) < 0) TEST_ERROR
@@ -7091,8 +7150,10 @@ test_copy_soft_link(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fa
     /* copy the dataset from SRC to DST */
     if(H5Ocopy(fid_src, NAME_LINK_SOFT, fid_dst, NAME_DATASET_SIMPLE, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
-    /* open the dataset through the soft link for copy */
-    if((did = H5Dopen2(fid_src, NAME_LINK_SOFT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if(!test_open) {
+        /* open the dataset through the soft link for copy */
+        if((did = H5Dopen2(fid_src, NAME_LINK_SOFT, H5P_DEFAULT)) < 0) TEST_ERROR
+    }
 
     /* open the destination dataset */
     if((did2 = H5Dopen2(fid_dst, NAME_DATASET_SIMPLE, H5P_DEFAULT)) < 0) TEST_ERROR
@@ -7593,14 +7654,18 @@ error:
  *-------------------------------------------------------------------------
  */
 static int
-test_copy_old_layout(hid_t fcpl_dst, hid_t fapl)
+test_copy_old_layout(hid_t fcpl_dst, hid_t fapl, hbool_t test_open)
 {
     hid_t fid_src = -1, fid_dst = -1;           /* File IDs */
     hid_t did = -1, did2 = -1;                  /* Dataset IDs */
     const char *src_filename = H5_get_srcdir_filename(FILE_OLD_LAYOUT); /* Corrected test file name */
     char dst_filename[NAME_BUF_SIZE];
 
-    TESTING("H5Ocopy(): dataset with old layout format");
+    if(test_open) {
+        TESTING("H5Ocopy(): opened dataset with old layout format");
+    } else {
+        TESTING("H5Ocopy(): dataset with old layout format");
+    }
 
     /* Initialize the destination filename */
     h5_fixname(FILENAME[1], fapl, dst_filename, sizeof dst_filename);
@@ -7617,11 +7682,18 @@ test_copy_old_layout(hid_t fcpl_dst, hid_t fapl)
     /* Create an uncopied object in destination file so that addresses in source and destination files aren't the same */
     if(H5Gclose(H5Gcreate2(fid_dst, NAME_GROUP_UNCOPIED, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
 
+    if(test_open) {
+        /* open the source dataset */
+        if((did = H5Dopen2(fid_src, NAME_OLD_FORMAT, H5P_DEFAULT)) < 0) TEST_ERROR
+    }
+
     /* copy the dataset from SRC to DST */
     if(H5Ocopy(fid_src, NAME_OLD_FORMAT, fid_dst, NAME_DATASET_SIMPLE, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
-    /* open the source dataset */
-    if((did = H5Dopen2(fid_src, NAME_OLD_FORMAT, H5P_DEFAULT)) < 0) TEST_ERROR
+    if(!test_open) {
+        /* open the source dataset */
+        if((did = H5Dopen2(fid_src, NAME_OLD_FORMAT, H5P_DEFAULT)) < 0) TEST_ERROR
+    }
 
     /* open the destination dataset */
     if((did2 = H5Dopen2(fid_dst, NAME_DATASET_SIMPLE, H5P_DEFAULT)) < 0) TEST_ERROR
@@ -7962,6 +8034,9 @@ error:
  * Purpose:     Create a dataset that uses a named variable length datatype
  *              in SRC file and copy it to DST file
  *
+ *              Note: The parameter "test_open" is added to test for H5Ocopy when 
+ *                    the dataset is open in the file (HDFFV-7853).
+ *
  * Return:      Success:        0
  *              Failure:        number of errors
  *
@@ -7971,7 +8046,7 @@ error:
  *-------------------------------------------------------------------------
  */
 static int
-test_copy_dataset_chunked_named_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl)
+test_copy_dataset_chunked_named_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl, hbool_t test_open)
 {
     hid_t fid_src = -1, fid_dst = -1;           /* File IDs */
     hid_t tid = -1, tid_copy=-1;                /* Datatype ID */
@@ -7986,7 +8061,11 @@ test_copy_dataset_chunked_named_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fap
     char src_filename[NAME_BUF_SIZE];
     char dst_filename[NAME_BUF_SIZE];
 
-    TESTING("H5Ocopy(): chunked dataset with named VLEN datatype");
+    if(test_open) {
+        TESTING("H5Ocopy(): chunked and opened dataset with named VLEN datatype");
+    } else {
+        TESTING("H5Ocopy(): chunked dataset with named VLEN datatype");
+    }
 
     /* set initial data values */
     for(i = 0; i < DIM_SIZE_1; i++) {
@@ -8037,15 +8116,18 @@ test_copy_dataset_chunked_named_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fap
     /* close the datatype */
     if(H5Tclose(tid) < 0) TEST_ERROR
 
-    /* close the dataset */
-    if(H5Dclose(did) < 0) TEST_ERROR
+    if(!test_open) {
 
-    /* close the SRC file */
-    if(H5Fclose(fid_src) < 0) TEST_ERROR
+        /* close the dataset */
+        if(H5Dclose(did) < 0) TEST_ERROR
 
+        /* close the SRC file */
+        if(H5Fclose(fid_src) < 0) TEST_ERROR
 
-    /* open the source file with read-only */
-    if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+
+        /* open the source file with read-only */
+        if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+    }
 
     /* create destination file */
     if((fid_dst = H5Fcreate(dst_filename, H5F_ACC_TRUNC, fcpl_dst, dst_fapl)) < 0) TEST_ERROR
@@ -8056,8 +8138,10 @@ test_copy_dataset_chunked_named_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fap
     /* copy the dataset from SRC to DST */
     if(H5Ocopy(fid_src, NAME_DATASET_VL, fid_dst, NAME_DATASET_VL, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
-    /* open the dataset for copy */
-    if((did = H5Dopen2(fid_src, NAME_DATASET_VL, H5P_DEFAULT)) < 0) TEST_ERROR
+    if(!test_open) {
+        /* open the dataset for copy */
+        if((did = H5Dopen2(fid_src, NAME_DATASET_VL, H5P_DEFAULT)) < 0) TEST_ERROR
+    }
 
     /* open the destination dataset */
     if((did2 = H5Dopen2(fid_dst, NAME_DATASET_VL, H5P_DEFAULT)) < 0) TEST_ERROR
@@ -8438,6 +8522,9 @@ error:
  * Purpose:     Create a compact dataset w/nested VLEN datatype
  *              in SRC file and copy it to DST file
  *
+ *              Note: The parameter "test_open" is added to test for H5Ocopy when 
+ *                    the dataset is open in the file (HDFFV-7853).
+ *
  * Return:      Success:        0
  *              Failure:        number of errors
  *
@@ -8447,7 +8534,7 @@ error:
  *-------------------------------------------------------------------------
  */
 static int
-test_copy_dataset_contig_vl_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl)
+test_copy_dataset_contig_vl_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl, hbool_t test_open)
 {
     hid_t fid_src = -1, fid_dst = -1;           /* File IDs */
     hid_t tid=-1, tid2=-1;                      /* Datatype ID */
@@ -8462,7 +8549,11 @@ test_copy_dataset_contig_vl_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, h
     char src_filename[NAME_BUF_SIZE];
     char dst_filename[NAME_BUF_SIZE];
 
-    TESTING("H5Ocopy(): contigous dataset with nested VLEN datatype");
+    if(test_open) {
+        TESTING("H5Ocopy(): contigous and opened dataset with nested VLEN datatype");
+    } else {
+        TESTING("H5Ocopy(): contigous dataset with nested VLEN datatype");
+    }
 
     /* set initial data values */
     for(i=0; i<DIM_SIZE_1; i++) {
@@ -8519,15 +8610,17 @@ test_copy_dataset_contig_vl_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, h
     /* close compact plist */
     if(H5Pclose(pid) < 0) TEST_ERROR
 
-    /* close the dataset */
-    if(H5Dclose(did) < 0) TEST_ERROR
+    if(!test_open) {
+        /* close the dataset */
+        if(H5Dclose(did) < 0) TEST_ERROR
 
-    /* close the SRC file */
-    if(H5Fclose(fid_src) < 0) TEST_ERROR
+        /* close the SRC file */
+        if(H5Fclose(fid_src) < 0) TEST_ERROR
 
 
-    /* open the source file with read-only */
-    if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+        /* open the source file with read-only */
+        if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+    }
 
     /* create destination file */
     if((fid_dst = H5Fcreate(dst_filename, H5F_ACC_TRUNC, fcpl_dst, dst_fapl)) < 0) TEST_ERROR
@@ -8538,8 +8631,10 @@ test_copy_dataset_contig_vl_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, h
     /* copy the dataset from SRC to DST */
     if(H5Ocopy(fid_src, NAME_DATASET_VL_VL, fid_dst, NAME_DATASET_VL_VL, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
-    /* open the dataset for copy */
-    if((did = H5Dopen2(fid_src, NAME_DATASET_VL_VL, H5P_DEFAULT)) < 0) TEST_ERROR
+    if(!test_open) {
+        /* open the dataset for copy */
+        if((did = H5Dopen2(fid_src, NAME_DATASET_VL_VL, H5P_DEFAULT)) < 0) TEST_ERROR
+    }
 
     /* open the destination dataset */
     if((did2 = H5Dopen2(fid_dst, NAME_DATASET_VL_VL, H5P_DEFAULT)) < 0) TEST_ERROR
@@ -8801,6 +8896,9 @@ error:
  * Purpose:     Create a dataset that uses a named variable length datatype
  *              in SRC file and copy it to DST file
  *
+ *              Note: The parameter "test_open" is added to test for H5Ocopy when 
+ *                    the dataset is open in the file (HDFFV-7853).
+ *
  * Return:      Success:        0
  *              Failure:        number of errors
  *
@@ -8810,7 +8908,7 @@ error:
  *-------------------------------------------------------------------------
  */
 static int
-test_copy_dataset_compressed_vl_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl)
+test_copy_dataset_compressed_vl_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl, hbool_t test_open)
 {
     hid_t fid_src = -1, fid_dst = -1;           /* File IDs */
     hid_t tid = -1, tid2=-1;       /* Datatype ID */
@@ -8826,7 +8924,11 @@ test_copy_dataset_compressed_vl_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fap
     char src_filename[NAME_BUF_SIZE];
     char dst_filename[NAME_BUF_SIZE];
 
-    TESTING("H5Ocopy(): compressed dataset with nested VLEN datatype");
+    if(test_open) {
+        TESTING("H5Ocopy(): compressed and opened dataset with nested VLEN datatype");
+    } else {
+        TESTING("H5Ocopy(): compressed dataset with nested VLEN datatype");
+    }
 
     /* set initial data values */
     for(i=0; i<DIM_SIZE_1; i++) {
@@ -8884,16 +8986,19 @@ test_copy_dataset_compressed_vl_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fap
     /* close compact plist */
     if(H5Pclose(pid) < 0) TEST_ERROR
 
-    /* close the dataset */
-    if(H5Dclose(did) < 0) TEST_ERROR
+    if(!test_open) {
 
-    /* close the SRC file */
-    if(H5Fclose(fid_src) < 0) TEST_ERROR
+        /* close the dataset */
+        if(H5Dclose(did) < 0) TEST_ERROR
 
+        /* close the SRC file */
+        if(H5Fclose(fid_src) < 0) TEST_ERROR
 
-    /* open the source file with read-only */
-    if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
 
+        /* open the source file with read-only */
+        if((fid_src = H5Fopen(src_filename, H5F_ACC_RDONLY, src_fapl)) < 0) TEST_ERROR
+    }
+  
     /* create destination file */
     if((fid_dst = H5Fcreate(dst_filename, H5F_ACC_TRUNC, fcpl_dst, dst_fapl)) < 0) TEST_ERROR
 
@@ -8902,8 +9007,10 @@ test_copy_dataset_compressed_vl_vl(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fap
     /* copy the dataset from SRC to DST */
     if(H5Ocopy(fid_src, NAME_DATASET_VL_VL, fid_dst, NAME_DATASET_VL_VL, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
-    /* open the dataset for copy */
-    if((did = H5Dopen2(fid_src, NAME_DATASET_VL_VL, H5P_DEFAULT)) < 0) TEST_ERROR
+    if(!test_open) {
+        /* open the dataset for copy */
+        if((did = H5Dopen2(fid_src, NAME_DATASET_VL_VL, H5P_DEFAULT)) < 0) TEST_ERROR
+    }
 
     /* open the destination dataset */
     if((did2 = H5Dopen2(fid_dst, NAME_DATASET_VL_VL, H5P_DEFAULT)) < 0) TEST_ERROR
@@ -9584,6 +9691,189 @@ error:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    test_copy_null_ref_open
+ *
+ * Purpose:     Creates 2 datasets with references, one with object and
+ *              the other with region references.  Copies these datasets
+ *              to a new file without expanding references, causing them
+ *              to become NULL.  Next, copies these references to a third
+ *              file with expanding references, to verify that NULL
+ *              references are handled correctly.
+ *
+ *              Note: this is copied from test_copy_null_ref() with modifications
+ *              to test for opened datasets in the files.
+ *
+ * Return:      Success:        0
+ *              Failure:        number of errors
+ *
+ * Programmer:  Neil Fortner
+ *              Wednesday, March 31, 2010
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+test_copy_null_ref_open(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst_fapl)
+{
+    hid_t fid1 = -1, fid2 = -1, fid3 = -1;      /* File IDs */
+    hid_t sid = -1;                             /* Dataspace ID */
+    hid_t pid = -1;                             /* Object copy property list ID */
+    hid_t did1 = -1, did2 = -1;                 /* Dataset IDs */
+    hid_t did3 = -1, did4 = -1;                 /* Dataset IDs */
+    hid_t did5 = -1, did6 = -1;                 /* Dataset IDs */
+    hid_t dcpl = -1;                            /* Dataset creation property list */
+    hsize_t chunk_dim1d[1] = {2};               /* Chunk dimensions */
+    hsize_t dim1d[1] = {3};                     /* Dataset dimensions */
+    hobj_ref_t obj_buf[3];                      /* Buffer for object refs */
+    hdset_reg_ref_t reg_buf[3];                 /* Buffer for region refs */
+    char zeros[MAX(sizeof(obj_buf),sizeof(reg_buf))]; /* Array of zeros, for memcmp */
+    char src_filename[NAME_BUF_SIZE];
+    char mid_filename[NAME_BUF_SIZE];
+    char dst_filename[NAME_BUF_SIZE];
+
+    TESTING("H5Ocopy(): NULL references for opened datasets");
+
+    /* Initialize "zeros" array */
+    HDmemset(zeros, 0, sizeof(zeros));
+
+    /* Initialize the filenames */
+    h5_fixname(FILENAME[0], src_fapl, src_filename, sizeof src_filename);
+    h5_fixname(FILENAME[1], src_fapl, mid_filename, sizeof mid_filename);
+    h5_fixname(FILENAME[2], dst_fapl, dst_filename, sizeof dst_filename);
+
+    /* Reset file address checking info */
+    addr_reset();
+
+    /* Create source file */
+    if((fid1 = H5Fcreate(src_filename, H5F_ACC_TRUNC, fcpl_src, src_fapl)) < 0)
+        TEST_ERROR
+
+    /* Create dataspace */
+    if((sid = H5Screate_simple(1, dim1d, NULL)) < 0) TEST_ERROR
+
+     /* create and set chunk plist */
+    if((dcpl = H5Pcreate(H5P_DATASET_CREATE)) < 0) TEST_ERROR
+    if(H5Pset_chunk(dcpl, 1, chunk_dim1d) < 0) TEST_ERROR
+    if(H5Pset_deflate(dcpl, 9) < 0) TEST_ERROR
+    if(H5Pset_chunk_opts(dcpl, H5D_CHUNK_DONT_FILTER_PARTIAL_CHUNKS) < 0) TEST_ERROR
+
+    /* Create object reference dataset at SRC file */
+    if((did1 = H5Dcreate2(fid1, "obj_ref_dset", H5T_STD_REF_OBJ, sid,
+            H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0) TEST_ERROR
+
+    /* Create region reference dataset at SRC file */
+    if((did2 = H5Dcreate2(fid1, "reg_ref_dset", H5T_STD_REF_DSETREG,
+            sid, H5P_DEFAULT, dcpl, H5P_DEFAULT)) < 0) TEST_ERROR
+
+    /* Create references */
+    if(H5Rcreate(&obj_buf[0], did1, ".", H5R_OBJECT, (hid_t)-1) < 0) TEST_ERROR
+    if(H5Rcreate(&obj_buf[1], did2, ".", H5R_OBJECT, (hid_t)-1) < 0) TEST_ERROR
+    if(H5Rcreate(&reg_buf[0], did1, ".", H5R_DATASET_REGION, sid) < 0)
+        TEST_ERROR
+    if(H5Rcreate(&reg_buf[1], did2, ".", H5R_DATASET_REGION, sid) < 0)
+        TEST_ERROR
+
+    /* Write data into file */
+    if(H5Dwrite(did1, H5T_STD_REF_OBJ, H5S_ALL, H5S_ALL, H5P_DEFAULT, obj_buf)
+            < 0) TEST_ERROR
+    if(H5Dwrite(did2, H5T_STD_REF_DSETREG, H5S_ALL, H5S_ALL, H5P_DEFAULT,
+            reg_buf) < 0) TEST_ERROR
+
+
+    /* Create middle file */
+    if((fid2 = H5Fcreate(mid_filename, H5F_ACC_TRUNC, fcpl_src, src_fapl)) < 0)
+        TEST_ERROR
+
+    /* Copy the source file to the middle file.  Note the expand references
+     * flag is not set. */
+    if(H5Ocopy(fid1, "/", fid2, "/A", H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
+
+    /* Close datasets in source file */
+    if(H5Dclose(did1) < 0) TEST_ERROR
+    if(H5Dclose(did2) < 0) TEST_ERROR
+
+    /* Close source file */
+    if(H5Fclose(fid1) < 0) TEST_ERROR
+
+    /* Open copied datasets */
+    if((did3 = H5Dopen2(fid2, "/A/obj_ref_dset", H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did4 = H5Dopen2(fid2, "/A/reg_ref_dset", H5P_DEFAULT)) < 0) TEST_ERROR
+
+    /* Read copied datasets */
+    if(H5Dread(did3, H5T_STD_REF_OBJ, H5S_ALL, H5S_ALL, H5P_DEFAULT, obj_buf)
+          < 0) TEST_ERROR
+    if(H5Dread(did4, H5T_STD_REF_DSETREG, H5S_ALL, H5S_ALL, H5P_DEFAULT,
+          reg_buf) < 0) TEST_ERROR
+
+    /* Verify that the references contain only "0" bytes */
+    if(HDmemcmp(obj_buf, zeros, sizeof(obj_buf))) TEST_ERROR
+    if(HDmemcmp(reg_buf, zeros, sizeof(reg_buf))) TEST_ERROR
+
+    /* Create destination file */
+    if((fid3 = H5Fcreate(dst_filename, H5F_ACC_TRUNC, fcpl_dst, dst_fapl)) < 0)
+       TEST_ERROR
+
+    /* Create object copy property list */
+    if((pid = H5Pcreate(H5P_OBJECT_COPY)) < 0) TEST_ERROR
+
+    /* Set the "expand references" flag */
+    if(H5Pset_copy_object(pid, H5O_COPY_EXPAND_REFERENCE_FLAG) < 0) TEST_ERROR
+
+    /* Copy the middle file to the destination file.  Note the expand references
+     * flag *is* set, even though the references are now NULL. */
+    if(H5Ocopy(fid2, "/", fid3, "/AA", pid, H5P_DEFAULT) < 0) TEST_ERROR
+
+    /* Close datasets in middle file */
+    if(H5Dclose(did3) < 0) TEST_ERROR
+    if(H5Dclose(did4) < 0) TEST_ERROR
+
+    /* Close the middle file */
+    if(H5Fclose(fid2) < 0) TEST_ERROR
+
+    /* Open copied datasets */
+    if((did5 = H5Dopen2(fid3, "/AA/A/obj_ref_dset", H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did6 = H5Dopen2(fid3, "/AA/A/reg_ref_dset", H5P_DEFAULT)) < 0) TEST_ERROR
+
+    /* Read copied datasets */
+    if(H5Dread(did5, H5T_STD_REF_OBJ, H5S_ALL, H5S_ALL, H5P_DEFAULT, obj_buf)
+            < 0) TEST_ERROR
+    if(H5Dread(did6, H5T_STD_REF_DSETREG, H5S_ALL, H5S_ALL, H5P_DEFAULT,
+            reg_buf) < 0) TEST_ERROR
+
+    /* Verify that the references contain only "0" bytes */
+    if(HDmemcmp(obj_buf, zeros, sizeof(obj_buf))) TEST_ERROR
+    if(HDmemcmp(reg_buf, zeros, sizeof(reg_buf))) TEST_ERROR
+
+    /* Close */
+    if(H5Pclose(pid) < 0) TEST_ERROR
+    if(H5Pclose(dcpl) < 0) TEST_ERROR
+    if(H5Dclose(did5) < 0) TEST_ERROR
+    if(H5Dclose(did6) < 0) TEST_ERROR
+    if(H5Fclose(fid3) < 0) TEST_ERROR
+    if(H5Sclose(sid) < 0) TEST_ERROR
+
+    PASSED();
+    return 0;
+
+error:
+    H5E_BEGIN_TRY {
+        H5Pclose(pid);
+        H5Pclose(dcpl);
+        H5Sclose(sid);
+        H5Dclose(did1);
+        H5Dclose(did2);
+        H5Dclose(did3);
+        H5Dclose(did4);
+        H5Dclose(did5);
+        H5Dclose(did6);
+        H5Fclose(fid1);
+        H5Fclose(fid2);
+        H5Fclose(fid3);
+    } H5E_END_TRY;
+    return 1;
+} /* end test_copy_null_ref_open */
+
+
+/*-------------------------------------------------------------------------
  * Function:    test_copy_attr_crt_order
  *
  * Purpose:     Tests copying attributes with creation order tracked, with
@@ -13309,9 +13599,12 @@ test_copy_dataset_open(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst
     hid_t sid = -1;                             /* Dataspace ID */
     hid_t tid = -1;                             /* Datatype ID */
     hid_t did = -1, did2 = -1;                  /* Dataset IDs */
+    hid_t did3 = -1, did4 = -1;                 /* Dataset IDs */
     hid_t gid = -1, gid2 = -1;                  /* Group IDs */
+    hid_t pid = -1;                             /* Dataset creation property list */
+    hsize_t chunk_dim2d[2] = {CHUNK_SIZE_1, CHUNK_SIZE_2};   /* Chunk dimension sizes */
     int buf[DIM_SIZE_1][DIM_SIZE_2];            /* Buffer for writing data */
-    int newbuf[DIM_SIZE_1][DIM_SIZE_2];		/* Buffer for writing data */
+    int newbuf[DIM_SIZE_1][DIM_SIZE_2];         /* Buffer for writing data */
     hsize_t dim2d[2];                           /* Dataset dimensions */
     int i, j;                                   /* local index variables */
     char src_filename[NAME_BUF_SIZE];
@@ -13352,14 +13645,23 @@ test_copy_dataset_open(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst
     /* create 2D dataspace */
     if((sid = H5Screate_simple(2, dim2d, NULL)) < 0) TEST_ERROR
 
-    /* create 2D int dataset in SRC file */
+    /* create and set chunk plist */
+    if((pid = H5Pcreate(H5P_DATASET_CREATE)) < 0) TEST_ERROR
+    if(H5Pset_chunk(pid, 2, chunk_dim2d) < 0) TEST_ERROR
+
+    /* create 2D dataset in SRC file */
     if((did = H5Dcreate2(fid_src, NAME_DATASET_SIMPLE, H5T_NATIVE_INT, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) TEST_ERROR
 
+    /* create 2D chunked dataset in SRC file */
+    if((did2 = H5Dcreate2(fid_src, NAME_DATASET_CHUNKED, H5T_NATIVE_INT, sid, H5P_DEFAULT, pid, H5P_DEFAULT)) < 0) TEST_ERROR
+
     /* write data to the dataset */
     if(H5Dwrite(did, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0) TEST_ERROR
-
+    if(H5Dwrite(did2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf) < 0) TEST_ERROR
+                                
     /* attach attributes to the dataset */
     if(test_copy_attach_attributes(did, H5T_NATIVE_INT) < 0) TEST_ERROR
+    if(test_copy_attach_attributes(did2, H5T_NATIVE_INT) < 0) TEST_ERROR
 
     /* 
      * Test case 1 
@@ -13370,74 +13672,94 @@ test_copy_dataset_open(hid_t fcpl_src, hid_t fcpl_dst, hid_t src_fapl, hid_t dst
      */
     /* copy the opened dataset to another location in SRC file */
     if(H5Ocopy(fid_src, NAME_DATASET_SIMPLE, fid_src, NAME_DATASET_SIMPLE2, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
+    if(H5Ocopy(fid_src, NAME_DATASET_CHUNKED, fid_src, NAME_DATASET_CHUNKED2, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
     /* open the copied dataset */
-    if((did2 = H5Dopen2(fid_src, NAME_DATASET_SIMPLE2, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did3 = H5Dopen2(fid_src, NAME_DATASET_SIMPLE2, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did4 = H5Dopen2(fid_src, NAME_DATASET_CHUNKED2, H5P_DEFAULT)) < 0) TEST_ERROR
 
     /* Check if the datasets are equal */
-    if(compare_datasets(did, did2, H5P_DEFAULT, buf) != TRUE) TEST_ERROR
+    if(compare_datasets(did, did3, H5P_DEFAULT, buf) != TRUE) TEST_ERROR
+    if(compare_datasets(did2, did4, H5P_DEFAULT, buf) != TRUE) TEST_ERROR
 
     /* close the copied dataset */
-    if(H5Dclose(did2) < 0) TEST_ERROR
+    if(H5Dclose(did3) < 0) TEST_ERROR
+    if(H5Dclose(did4) < 0) TEST_ERROR
 
     /* 
      * Copy to another file
      */
     /* copy the opened dataset from SRC to DST */
     if(H5Ocopy(fid_src, NAME_DATASET_SIMPLE, fid_dst, NAME_DATASET_SIMPLE, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
+    if(H5Ocopy(fid_src, NAME_DATASET_CHUNKED, fid_dst, NAME_DATASET_CHUNKED, H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
     /* open the copied dataset in DST file */
-    if((did2 = H5Dopen2(fid_dst, NAME_DATASET_SIMPLE, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did3 = H5Dopen2(fid_dst, NAME_DATASET_SIMPLE, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did4 = H5Dopen2(fid_dst, NAME_DATASET_CHUNKED, H5P_DEFAULT)) < 0) TEST_ERROR
 
     /* Check if the datasets are equal */
-    if(compare_datasets(did, did2, H5P_DEFAULT, buf) != TRUE) TEST_ERROR
+    if(compare_datasets(did, did3, H5P_DEFAULT, buf) != TRUE) TEST_ERROR
+    if(compare_datasets(did2, did4, H5P_DEFAULT, buf) != TRUE) TEST_ERROR
 
     /* close the copied dataset in DST file */
-    if(H5Dclose(did2) < 0) TEST_ERROR
+    if(H5Dclose(did3) < 0) TEST_ERROR
+    if(H5Dclose(did4) < 0) TEST_ERROR
 
     /* close the dataset in SRC file */
     if(H5Dclose(did) < 0) TEST_ERROR
+    if(H5Dclose(did2) < 0) TEST_ERROR
 
     /* 
      * Test case 2 
      */
     /* reopen the dataset in SRC file */
     if((did = H5Dopen2(fid_src, NAME_DATASET_SIMPLE, H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did2 = H5Dopen2(fid_src, NAME_DATASET_CHUNKED, H5P_DEFAULT)) < 0) TEST_ERROR
 
     /* write another set of data to the dataset */
     if(H5Dwrite(did, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, newbuf) < 0) TEST_ERROR
+    if(H5Dwrite(did2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, newbuf) < 0) TEST_ERROR
 
     /* 
      * Copy within the same file
      */
     /* copy the opened dataset to another location in SRC file */
-    if(H5Ocopy(fid_src, NAME_DATASET_SIMPLE, fid_src, "NEW_DATASET", H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
+    if(H5Ocopy(fid_src, NAME_DATASET_SIMPLE, fid_src, "NEW_DATASET_SIMPLE", H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
+    if(H5Ocopy(fid_src, NAME_DATASET_CHUNKED, fid_src, "NEW_DATASET_CHUNKED", H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
     /* open the copied dataset */
-    if((did2 = H5Dopen2(fid_src, "NEW_DATASET", H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did3 = H5Dopen2(fid_src, "NEW_DATASET_SIMPLE", H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did4 = H5Dopen2(fid_src, "NEW_DATASET_CHUNKED", H5P_DEFAULT)) < 0) TEST_ERROR
 
     /* Check if the datasets are equal */
-    if(compare_datasets(did, did2, H5P_DEFAULT, newbuf) != TRUE) TEST_ERROR
+    if(compare_datasets(did, did3, H5P_DEFAULT, newbuf) != TRUE) TEST_ERROR
+    if(compare_datasets(did2, did4, H5P_DEFAULT, newbuf) != TRUE) TEST_ERROR
 
     /* close the copied dataset in SRC file */
-    if(H5Dclose(did2) < 0) TEST_ERROR
+    if(H5Dclose(did3) < 0) TEST_ERROR
+    if(H5Dclose(did4) < 0) TEST_ERROR
     /* 
      * Copy to another file
      */
     /* copy the opened dataset from SRC to DST */
-    if(H5Ocopy(fid_src, NAME_DATASET_SIMPLE, fid_dst, "NEW_DATASET", H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
+    if(H5Ocopy(fid_src, NAME_DATASET_SIMPLE, fid_dst, "NEW_DATASET_SIMPLE", H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
+    if(H5Ocopy(fid_src, NAME_DATASET_CHUNKED, fid_dst, "NEW_DATASET_CHUNKED", H5P_DEFAULT, H5P_DEFAULT) < 0) TEST_ERROR
 
     /* open the copied dataset in DST file */
-    if((did2 = H5Dopen2(fid_dst, "NEW_DATASET", H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did3 = H5Dopen2(fid_dst, "NEW_DATASET_SIMPLE", H5P_DEFAULT)) < 0) TEST_ERROR
+    if((did4 = H5Dopen2(fid_dst, "NEW_DATASET_CHUNKED", H5P_DEFAULT)) < 0) TEST_ERROR
 
     /* Check if the datasets are equal */
-    if(compare_datasets(did, did2, H5P_DEFAULT, newbuf) != TRUE) TEST_ERROR
+    if(compare_datasets(did, did3, H5P_DEFAULT, newbuf) != TRUE) TEST_ERROR
+    if(compare_datasets(did2, did4, H5P_DEFAULT, newbuf) != TRUE) TEST_ERROR
 
     /* close the copied dataset in DST file */
-    if(H5Dclose(did2) < 0) TEST_ERROR
+    if(H5Dclose(did3) < 0) TEST_ERROR
+    if(H5Dclose(did4) < 0) TEST_ERROR
 
     /* close the dataset at SRC file */
     if(H5Dclose(did) < 0) TEST_ERROR
+    if(H5Dclose(did2) < 0) TEST_ERROR
 
     /* 
      * Test case 3 
@@ -13696,15 +14018,28 @@ main(void)
         /* The tests... */
         nerrors += test_copy_dataset_simple(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
         nerrors += test_copy_dataset_simple_samefile(fcpl_src, src_fapl);
-        nerrors += test_copy_dataset_simple_empty(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
+
+        /* Test with dataset opened in the file or not */
+        nerrors += test_copy_dataset_simple_empty(fcpl_src, fcpl_dst, src_fapl, dst_fapl, FALSE);
+        nerrors += test_copy_dataset_simple_empty(fcpl_src, fcpl_dst, src_fapl, dst_fapl, TRUE);
+
         nerrors += test_copy_dataset_compound(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
         nerrors += test_copy_dataset_chunked(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
         nerrors += test_copy_dataset_chunked_empty(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
         nerrors += test_copy_dataset_chunked_sparse(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
         nerrors += test_copy_dataset_compressed(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
-        nerrors += test_copy_dataset_no_edge_filt(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
-        nerrors += test_copy_dataset_compact(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
-        nerrors += test_copy_dataset_multi_ohdr_chunks(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
+
+        /* Test with dataset opened in the file or not */
+        nerrors += test_copy_dataset_no_edge_filt(fcpl_src, fcpl_dst, src_fapl, dst_fapl, FALSE);
+        nerrors += test_copy_dataset_no_edge_filt(fcpl_src, fcpl_dst, src_fapl, dst_fapl, TRUE);
+
+        /* Test with dataset opened in the file or not */
+        nerrors += test_copy_dataset_compact(fcpl_src, fcpl_dst, src_fapl, dst_fapl, FALSE);
+        nerrors += test_copy_dataset_compact(fcpl_src, fcpl_dst, src_fapl, dst_fapl, TRUE);
+
+        nerrors += test_copy_dataset_multi_ohdr_chunks(fcpl_src, fcpl_dst, src_fapl, dst_fapl, FALSE);
+        nerrors += test_copy_dataset_multi_ohdr_chunks(fcpl_src, fcpl_dst, src_fapl, dst_fapl, TRUE);
+
         nerrors += test_copy_dataset_attr_named_dtype(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
 
         nerrors += test_copy_group_empty(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
@@ -13714,7 +14049,11 @@ main(void)
         nerrors += test_copy_group_loop(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
         nerrors += test_copy_group_wide_loop(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
         nerrors += test_copy_group_links(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
-        nerrors += test_copy_soft_link(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
+
+        /* Test with dataset opened in the file or not */
+        nerrors += test_copy_soft_link(fcpl_src, fcpl_dst, src_fapl, dst_fapl, FALSE);
+        nerrors += test_copy_soft_link(fcpl_src, fcpl_dst, src_fapl, dst_fapl, TRUE);
+
         nerrors += test_copy_ext_link(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
         nerrors += test_copy_exist(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
         nerrors += test_copy_path(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
@@ -13794,19 +14133,38 @@ main(void)
             nerrors += test_copy_attribute_compound_vlstr(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
             nerrors += test_copy_dataset_compact_named_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
             nerrors += test_copy_dataset_contig_named_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
-            nerrors += test_copy_dataset_chunked_named_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
+
+            /* Test with dataset opened in the file or not */
+            nerrors += test_copy_dataset_chunked_named_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl, FALSE);
+            nerrors += test_copy_dataset_chunked_named_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl, TRUE);
+
             nerrors += test_copy_dataset_compressed_named_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
             nerrors += test_copy_dataset_compact_vl_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
-            nerrors += test_copy_dataset_contig_vl_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
+
+            /* Test with dataset opened in the file or not */
+            nerrors += test_copy_dataset_contig_vl_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl, FALSE);
+            nerrors += test_copy_dataset_contig_vl_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl, TRUE);
+
             nerrors += test_copy_dataset_chunked_vl_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
-            nerrors += test_copy_dataset_compressed_vl_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
+
+            /* Test with dataset opened in the file or not */
+            nerrors += test_copy_dataset_compressed_vl_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl, FALSE);
+            nerrors += test_copy_dataset_compressed_vl_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl, TRUE);
+
             nerrors += test_copy_dataset_contig_cmpd_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
             nerrors += test_copy_dataset_chunked_cmpd_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
             nerrors += test_copy_dataset_compact_cmpd_vl(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
 
             nerrors += test_copy_same_file_named_datatype(fcpl_src, src_fapl);
-            nerrors += test_copy_old_layout(fcpl_dst, dst_fapl);
+
+            /* Test with dataset opened in the file or not */
+            nerrors += test_copy_old_layout(fcpl_dst, dst_fapl, FALSE);
+            nerrors += test_copy_old_layout(fcpl_dst, dst_fapl, TRUE);
+
+            /* Test with dataset opened in the file or not */
             nerrors += test_copy_null_ref(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
+            nerrors += test_copy_null_ref_open(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
+
             nerrors += test_copy_iterate(fcpl_src, fcpl_dst, src_fapl, dst_fapl);
         } /* end if */