Changes made based on code reviews.

24 files changed, 305 insertions, 103 deletions

diff --git a/src/H5Aint.c b/src/H5Aint.c
index 5c32e86..666f11d 100644
--- a/src/H5Aint.c
+++ b/src/H5Aint.c
@@ -1863,6 +1863,7 @@ herr_t
 H5A_set_version(const H5F_t *f, H5A_t *attr)
 {
     hbool_t type_shared, space_shared;  /* Flags to indicate that shared messages are used for this attribute */
+    uint8_t version;                    /* Message version */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -1884,18 +1885,22 @@ H5A_set_version(const H5F_t *f, H5A_t *attr)
 
     /* Check which version to encode attribute with */
     if(attr->shared->encoding != H5T_CSET_ASCII)
-        attr->shared->version = H5O_ATTR_VERSION_3;   /* Write version which includes the character encoding */
+        version = H5O_ATTR_VERSION_3;   /* Write version which includes the character encoding */
     else if(type_shared || space_shared)
-        attr->shared->version = H5O_ATTR_VERSION_2;   /* Write out version with flag for indicating shared datatype or dataspace */
+        version = H5O_ATTR_VERSION_2;   /* Write out version with flag for indicating shared datatype or dataspace */
     else
-        attr->shared->version = H5O_ATTR_VERSION_1;   /* Write out basic version */
+        version = H5O_ATTR_VERSION_1;   /* Write out basic version */
 
     /* Upgrade to the version indicated by the file's low bound if higher */
-    attr->shared->version = MAX(attr->shared->version, (uint8_t)H5O_attr_ver_bounds[H5F_LOW_BOUND(f)]);
+    version = MAX(version, (uint8_t)H5O_attr_ver_bounds[H5F_LOW_BOUND(f)]);
 
-    /* File bound check */
-    if(attr->shared->version > H5O_attr_ver_bounds[H5F_HIGH_BOUND(f)])
+    /* Version bounds check */
+    if(version > H5O_attr_ver_bounds[H5F_HIGH_BOUND(f)])
         HGOTO_ERROR(H5E_ATTR, H5E_BADRANGE, FAIL, "attribute version out of bounds")
+
+    /* Set the message version */
+    attr->shared->version = version;
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5A_set_version() */
diff --git a/src/H5Dint.c b/src/H5Dint.c
index c1a66ca..89dff1e 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -623,10 +623,10 @@ done:
 static herr_t
 H5D__init_type(H5F_t *file, const H5D_t *dset, hid_t type_id, const H5T_t *type)
 {
-    htri_t relocatable;                 /* Flag whether the type is relocatable */
-    htri_t immutable;                   /* Flag whether the type is immutable */
-    hbool_t use_v18_latest_format;      /* Flag indicating the 'latest datatype version support' is enabled */
-    herr_t ret_value = SUCCEED;         /* Return value */
+    htri_t relocatable;            /* Flag whether the type is relocatable */
+    htri_t immutable;              /* Flag whether the type is immutable */
+    hbool_t use_at_least_v18;      /* Flag indicating to use at least v18 format versions */
+    herr_t ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_STATIC
 
@@ -643,10 +643,11 @@ H5D__init_type(H5F_t *file, const H5D_t *dset, hid_t type_id, const H5T_t *type)
     if((immutable = H5T_is_immutable(type)) < 0)
         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "can't check datatype?")
 
-    use_v18_latest_format = (H5F_LOW_BOUND(file) >= H5F_LIBVER_V18);
+    /* To use at least v18 format versions or not */
+    use_at_least_v18 = (H5F_LOW_BOUND(file) >= H5F_LIBVER_V18);
 
     /* Copy the datatype if it's a custom datatype or if it'll change when it's location is changed */
-    if(!immutable || relocatable || use_v18_latest_format) {
+    if(!immutable || relocatable || use_at_least_v18) {
         /* Copy datatype for dataset */
         if((dset->shared->type = H5T_copy(type, H5T_COPY_ALL)) == NULL)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTCOPY, FAIL, "can't copy datatype")
@@ -786,6 +787,7 @@ H5D__update_oh_info(H5F_t *file, hid_t dxpl_id, H5D_t *dset, hid_t dapl_id)
     H5D_fill_value_t    fill_status;    /* Fill value status */
     hbool_t             fill_changed = FALSE;   /* Flag indicating the fill value was changed */
     hbool_t             layout_init = FALSE;    /* Flag to indicate that chunk information was initialized */
+    hbool_t             use_at_least_v18;       /* Flag indicating to use at least v18 format versions */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_STATIC
@@ -800,6 +802,9 @@ H5D__update_oh_info(H5F_t *file, hid_t dxpl_id, H5D_t *dset, hid_t dapl_id)
     type = dset->shared->type;
     fill_prop = &dset->shared->dcpl_cache.fill;
 
+    /* To use at least v18 format versions or not */
+    use_at_least_v18 = (H5F_LOW_BOUND(file) >= H5F_LIBVER_V18);
+
     /* Retrieve "defined" status of fill value */
     if(H5P_is_fill_value_defined(fill_prop, &fill_status) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't tell if fill value defined")
@@ -878,8 +883,8 @@ H5D__update_oh_info(H5F_t *file, hid_t dxpl_id, H5D_t *dset, hid_t dapl_id)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update new fill value header message")
 
     /* If there is valid information for the old fill value struct, add it */
-    /* (only if we aren't trying to write the 'latest fill message version support') */
-    if(fill_prop->buf && (H5F_LOW_BOUND(file) < H5F_LIBVER_V18)) {
+    /* (only if we aren't using v18 format versions and above */
+    if(fill_prop->buf && !use_at_least_v18) {
         H5O_fill_t old_fill_prop;       /* Copy of fill value property, for writing as "old" fill value */
 
         /* Shallow copy the fill value property */
@@ -931,10 +936,10 @@ H5D__update_oh_info(H5F_t *file, hid_t dxpl_id, H5D_t *dset, hid_t dapl_id)
 #endif /* H5O_ENABLE_BOGUS */
 
     /* Add a modification time message, if using older format. */
-    /* (If using the latest 'no modification time message' version support, the modification time is part of the object
+    /* (If using v18 format versions and above, the the modification time is part of the object
      *  header and doesn't use a separate message -QAK)
      */
-    if(H5F_LOW_BOUND(file) < H5F_LIBVER_V18)
+    if(!use_at_least_v18)
         if(H5O_touch_oh(file, dxpl_id, oh, TRUE) < 0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update modification time message")
 
diff --git a/src/H5Dlayout.c b/src/H5Dlayout.c
index 5a4d537..980b810 100644
--- a/src/H5Dlayout.c
+++ b/src/H5Dlayout.c
@@ -46,9 +46,10 @@
 /* Package Variables */
 /*********************/
 
+/* Format version bounds for layout */
 const unsigned H5O_layout_ver_bounds[] = {
     H5O_LAYOUT_VERSION_1,       /* H5F_LIBVER_EARLIEST */
-    H5O_LAYOUT_VERSION_3,       /* H5F_LIBVER_V18 */
+    H5O_LAYOUT_VERSION_3,       /* H5F_LIBVER_V18 */  /* H5O_LAYOUT_VERSION_DEFAULT */
     H5O_LAYOUT_VERSION_LATEST   /* H5F_LIBVER_LATEST */
 };
 
@@ -289,16 +290,15 @@ done:
  *
  * Return:      Non-negative on success/Negative on failure
  *
- * Programmer:  Quincey Koziol
- *              Thursday, January 15, 2009
+ * Programmer:  Vailin Choi; December 2017
  *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5D__layout_set_version(H5F_t *f, H5O_layout_t *layout)
 {
-    unsigned vers;
-    herr_t ret_value = SUCCEED;         /* Return value */
+    unsigned version;           /* Message version */
+    herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -307,12 +307,15 @@ H5D__layout_set_version(H5F_t *f, H5O_layout_t *layout)
     HDassert(f);
 
     /* Upgrade to the version indicated by the file's low bound if higher */
-    layout->version = MAX(layout->version, H5O_layout_ver_bounds[H5F_LOW_BOUND(f)]);
+    version = MAX(layout->version, H5O_layout_ver_bounds[H5F_LOW_BOUND(f)]);
 
-    /* File bound check */
-    if(layout->version > H5O_layout_ver_bounds[H5F_HIGH_BOUND(f)])
+    /* Version bounds check */
+    if(version > H5O_layout_ver_bounds[H5F_HIGH_BOUND(f)])
         HGOTO_ERROR(H5E_DATASET, H5E_BADRANGE, FAIL, "layout version out of bounds")
 
+    /* Set the message version */
+    layout->version = version;
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5D__layout_set_version() */
diff --git a/src/H5F.c b/src/H5F.c
index c670e17..8e5f65a 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -1478,6 +1478,8 @@ H5Fstart_swmr_write(hid_t file_id)
     if(file->shared->sblock->super_vers < HDF5_SUPERBLOCK_VERSION_3)
         HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "file superblock version should be at least 3")
 
+    HDassert((file->shared->low_bound == H5F_LIBVER_V110) && (file->shared->high_bound == H5F_LIBVER_V110));
+
     /* Should not be marked for SWMR writing mode already */
     if(file->shared->sblock->status_flags & H5F_SUPER_SWMR_WRITE_ACCESS)
         HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "file already in SWMR writing mode")
@@ -1739,9 +1741,12 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:   H5Fset_libver_bounds (Internal library use)
+ * Function:    H5Fset_libver_bounds
  *
- * Purpose:    Set .... the "latest format" flag while a file is open.
+ * Purpose:     Set to a different low and high bounds while a file is open.
+ *              This public routine is introduced in place of 
+ *              H5Fset_latest_format() starting release 1.10.2.
+ *              See explanation for H5Fset_latest_format() in H5Fdeprec.c.
  *
  * Return:     Non-negative on success/Negative on failure
  *-------------------------------------------------------------------------
@@ -1759,12 +1764,9 @@ H5Fset_libver_bounds(hid_t file_id, H5F_libver_t low, H5F_libver_t high)
     if(NULL == (f = (H5F_t *)H5I_object_verify(file_id, H5I_FILE)))
         HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "not a file ID")
 
-    /* Call the flush routine, for this file */
-    if(H5F__flush(f, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file's cached information")
-
-    f->shared->low_bound = low;
-    f->shared->high_bound = high;
+    /* Call private set_libver_bounds function */
+    if(H5F_set_libver_bounds(f, low, high) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "cannot set low/high bounds")
 
 done:
     FUNC_LEAVE_API(ret_value)
diff --git a/src/H5Fdeprec.c b/src/H5Fdeprec.c
index 03f5df8..a9ffa43 100644
--- a/src/H5Fdeprec.c
+++ b/src/H5Fdeprec.c
@@ -143,5 +143,67 @@ done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Fget_info1() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Fset_latest_format
+ *
+ * Purpose:     Enable switching between latest or non-latest format while
+ *              a file is open.
+ *              This is deprecated starting release 1.10.2 and is modified
+ *              to call the private H5F_set_libver_bounds() to set the
+ *              bounds.
+ *
+ *              Before release 1.10.2, the library supports only two
+ *              combinations of low/high bounds: 
+ *                  (earliest, latest)
+ *                  (latest, latest)
+ *              Thus, this public routine does the job in switching 
+ *              between the two combinations listed above.
+ *
+ *              Starting release 1.10.2, we add v18 to the enumerated
+ *              define H5F_libver_t and the library supports five combinations
+ *              as below:
+ *                  (earliest, v18)
+ *                  (earliest, v10)
+ *                  (v18, v18)
+ *                  (v18, v10)
+ *                  (v10, v10)
+ *              So we introduce the new public routine H5Fset_libver_bounds()
+ *              in place of H5Fset_latest_format().
+ *              See also RFC: Setting Bounds for Object Creation in HDF5 1.10.0.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Vailin Choi; December 2017
+ *             
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Fset_latest_format(hid_t file_id, hbool_t latest_format)
+{
+    H5F_t *f;                               /* File */
+    H5F_libver_t low  = H5F_LIBVER_LATEST;  /* Low bound */
+    H5F_libver_t high = H5F_LIBVER_LATEST;  /* High bound */
+    herr_t ret_value = SUCCEED;             /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "ib", file_id, latest_format);
+
+    /* Check args */
+    if(NULL == (f = (H5F_t *)H5I_object_verify(file_id, H5I_FILE)))
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "not a file ID")
+
+    /* 'low' and 'high' are both initialized to LATEST.
+       If latest format is not expected, set 'low' to EARLIEST */
+    if(!latest_format)
+        low = H5F_LIBVER_EARLIEST;
+
+    /* Call private set_libver_bounds function to set the bounds */
+    if(H5F_set_libver_bounds(f, low, high) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "cannot set low/high bounds")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Fset_latest_format() */
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
diff --git a/src/H5Fint.c b/src/H5Fint.c
index f223195..79f0d06 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -671,9 +671,9 @@ H5F_new(H5F_file_t *shared, unsigned flags, hid_t fcpl_id, hid_t fapl_id, H5FD_t
         if(H5P_get(plist, H5F_ACS_META_CACHE_INIT_IMAGE_CONFIG_NAME, &(f->shared->mdc_initCacheImageCfg)) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get initial metadata cache resize config")
 
-        /* File format version high bound does not allow the generation of metadata cache image */
+        /* Format version high bound does not allow the generation of metadata cache image */
         if(f->shared->mdc_initCacheImageCfg.generate_image && f->shared->high_bound < H5F_LIBVER_V110)
-            HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, NULL, "file format version out of bound for cache image")
+            HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, NULL, "format version out of bound for cache image")
 
         /* Get the VFD values to cache */
         f->shared->maxaddr = H5FD_get_maxaddr(lf);
@@ -2313,6 +2313,38 @@ H5F_set_store_msg_crt_idx(H5F_t *f, hbool_t flag)
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* H5F_set_store_msg_crt_idx() */
 
+/*-------------------------------------------------------------------------
+ * Function:    H5F_set_libver_bounds()
+ *
+ * Purpose:     Set the file's low and high bound to the input parameters
+ *              'low' and 'high' respectively.
+ *              This is done only if the existing setting is different
+ *              from the inputs.
+ *
+ * Return:      SUCCEED on success, and FAIL on failure.
+ *
+ * Programmer:  Vailin Choi; December 2017
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_set_libver_bounds(H5F_t * f, H5F_libver_t low, H5F_libver_t high)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    /* Sanity checks */
+    HDassert(f);
+    HDassert(f->shared);
+
+    /* Set the bounds only if the existing setting is different from the inputs */
+    if(f->shared->low_bound != low || f->shared->high_bound != high) {
+        f->shared->low_bound = low;
+        f->shared->high_bound = high;
+    }
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* H5F_set_libver_bounds() */
+
 
 /*-------------------------------------------------------------------------
  * Function:    H5F_get_file_image
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 50325bb..ec98468 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -769,6 +769,7 @@ H5_DLL unsigned H5F_gc_ref(const H5F_t *f);
 H5_DLL unsigned H5F_use_latest_flags(const H5F_t *f, unsigned fl);
 H5_DLL hbool_t H5F_store_msg_crt_idx(const H5F_t *f);
 H5_DLL herr_t H5F_set_store_msg_crt_idx(H5F_t *f, hbool_t flag);
+H5_DLL herr_t H5F_set_libver_bounds(H5F_t * f, H5F_libver_t low, H5F_libver_t high);
 H5_DLL struct H5UC_t *H5F_grp_btree_shared(const H5F_t *f);
 H5_DLL herr_t H5F_set_grp_btree_shared(H5F_t *f, struct H5UC_t *rc);
 H5_DLL hbool_t H5F_use_tmp_space(const H5F_t *f);
diff --git a/src/H5Fpublic.h b/src/H5Fpublic.h
index 9364ee2..d333fa7 100644
--- a/src/H5Fpublic.h
+++ b/src/H5Fpublic.h
@@ -173,7 +173,7 @@ typedef struct H5F_sect_info_t {
     hsize_t             size;   /* Size of free space section */
 } H5F_sect_info_t;
 
-/* Library's file format versions */
+/* Library's format versions */
 typedef enum H5F_libver_t {
     H5F_LIBVER_ERROR = -1,
     H5F_LIBVER_EARLIEST = 0,    /* Use the earliest possible format for storing objects */
@@ -300,6 +300,7 @@ typedef struct H5F_info1_t {
 
 /* Function prototypes */
 H5_DLL herr_t H5Fget_info1(hid_t obj_id, H5F_info1_t *finfo);
+H5_DLL herr_t H5Fset_latest_format(hid_t file_id, hbool_t latest_format);
 
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
diff --git a/src/H5Fquery.c b/src/H5Fquery.c
index 6b641f1..5d7de9d 100644
--- a/src/H5Fquery.c
+++ b/src/H5Fquery.c
@@ -716,9 +716,14 @@ H5F_sieve_buf_size(const H5F_t *f)
  * Purpose:  Replaced a macro to retrieve the "garbage collect
  *           references flag" now that the generic properties are being used
  *           to store the values.
- e
- *                              is returned.
- *           Failure:    (should not happen)
+ *
+ * Return:  Success:    The "garbage collect references flag" is returned.
+ *          Failure:    (should not happen)
+ *
+ * Programmer:  Quincey Koziol
+ *              koziol@ncsa.uiuc.edu
+ *              Jul  8 2005
+ *
  *-------------------------------------------------------------------------
  */
 unsigned
diff --git a/src/H5Fsuper.c b/src/H5Fsuper.c
index 4c12cb9..d30434d 100644
--- a/src/H5Fsuper.c
+++ b/src/H5Fsuper.c
@@ -457,23 +457,46 @@ H5F__super_read(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t initial
     if(NULL == (sblock = (H5F_super_t *)H5AC_protect(f, meta_dxpl_id, H5AC_SUPERBLOCK, (haddr_t)0, &udata, rw_flags)))
         HGOTO_ERROR(H5E_FILE, H5E_CANTPROTECT, FAIL, "unable to load superblock")
 
-     /* Upgrade low bound to at least V18 when encountering version 2 superblock */
+    /* 
+     * When opening a file with SWMR-write access, the library will first
+     * check to ensure that superblock version 3 is used.  Otherwise fail 
+     * file open.
+     *
+     * Then the library will upgrade the file's low_bound depending on 
+     * superblock version as follows:
+     *      --version 0 or 1: no change to low_bound
+     *      --version 2: upgrade low_bound to at least V18
+     *      --version 3: upgrade low_bound to at least V110
+     *
+     * Upgrading low_bound will give the best format versions available for
+     * that superblock version.  Due to the possible upgrade, the fapl returned
+     * from H5Fget_access_plist() might indicate a low_bound higher than what
+     * the user originally set.
+     *
+     * After upgrading low_bound, the library will check to ensure that the
+     * superblock version does not exceed the version allowed by high_bound.
+     * Otherise fail file open.
+     *
+     * For details, please see RFC:Setting Bounds for Object Creation in HDF5 1.10.0.
+     */
+
+    /* Check to ensure that superblock version 3 is used for SWMR-write access */
+    if(H5F_INTENT(f) & H5F_ACC_SWMR_WRITE) {
+        if(sblock->super_vers  < HDF5_SUPERBLOCK_VERSION_3)
+            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "superblock version for SWMR is less than 3")
+    }
+
+    /* Upgrade low_bound to at least V18 when encountering version 2 superblock */
     if(sblock->super_vers == HDF5_SUPERBLOCK_VERSION_2)
         f->shared->low_bound = MAX(H5F_LIBVER_V18, f->shared->low_bound);
 
-    /* Upgrade low bound to at least V110 when encountering version 3 superblock or SWMR_WRITE */
-    if((sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_3) || (H5F_INTENT(f) & H5F_ACC_SWMR_WRITE))
+    /* Upgrade low_bound to at least V110 when encountering version 3 superblock */
+    if(sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_3)
         f->shared->low_bound = MAX(H5F_LIBVER_V110, f->shared->low_bound);
 
-    /* File bound check */
+    /* Version bounds check */
     if(sblock->super_vers > HDF5_superblock_ver_bounds[f->shared->high_bound])
-        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "superblock version out of bounds (high bound)")
-
-    /* SWMR requires at least superblock version 3 */
-    if(H5F_INTENT(f) & H5F_ACC_SWMR_WRITE) {
-        if(sblock->super_vers  < HDF5_superblock_ver_bounds[f->shared->low_bound])
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "superblock version out of bounds (low bound)")
-    }
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "superblock version exceeds high bound")
 
     /* Pin the superblock in the cache */
     if(H5AC_pin_protected_entry(sblock) < 0)
@@ -833,9 +856,9 @@ H5F__super_read(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t initial
             hbool_t     rw = ((rw_flags & H5AC__READ_ONLY_FLAG) == 0);
             H5O_mdci_t  mdci_msg;
 
-            /* Message exists but file format version high bound does not allow it */
+            /* Message exists but version high bound does not allow it */
             if(f->shared->high_bound < H5F_LIBVER_V110)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "file format version out of bound for metadata cache image")
+                HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "format version out of bound for metadata cache image")
 
             /* if the metadata cache image superblock extension message exists,
              * read its contents and pass the data on to the metadata cache.
@@ -1037,6 +1060,36 @@ H5F__super_init(H5F_t *f, hid_t dxpl_id)
 	    f->shared->fs_page_size == H5F_FILE_SPACE_PAGE_SIZE_DEF))
         non_default_fs_settings = TRUE;
 
+    /* 
+     * When creating a file with write access, the library will:
+     *      -- set superblock version to 0, 1 or 2 based on feature enabled
+     *      -- no change to low_bound
+     * When creating a file with SWMR-write access, the library will:
+     * (See explanation (#) below.)
+     *      -- set superblock version to 3
+     *      -- upgrade low_bound to at least V110
+     *
+     * Then the library will finalize superblock version to that allowed by 
+     * low_bound if that is higher.
+     * Lastly, the library will check to ensure the superblock version does not 
+     * exceed the version allowed by high_bound. Otherwise fail file open.
+     *
+     * For details, please see RFC:Setting Bounds for Object Creation in HDF5 1.10.0.
+     *
+     * (#)
+     * Version 3 superblock is introduced in 1.10 for SWMR due to the problem of
+     * the status_flags field in the superblock. The problem is discussed in
+     * jira issue SWMR-79 and also in the RFC: File Format Changes in HDF5 1.10.0.
+     * The file's low_bound is upgraded for SWMR so that the library will
+     * use the best format versions available in 1.10.  
+     * Due to the possible upgrade, the fapl returned from H5Fget_access_plist() 
+     * might indicate a low_bound higher than what the user originally set.
+     */
+
+    /* 
+     * Creating a file with SWMR-write access will
+     * upgrade superblock version and low_bound
+     */
     if(H5F_INTENT(f) & H5F_ACC_SWMR_WRITE) {
         super_vers = HDF5_SUPERBLOCK_VERSION_3;
         f->shared->low_bound = MAX(H5F_LIBVER_V110, f->shared->low_bound);
@@ -1060,10 +1113,10 @@ H5F__super_init(H5F_t *f, hid_t dxpl_id)
     else if(sblock->btree_k[H5B_CHUNK_ID] != HDF5_BTREE_CHUNK_IK_DEF)
         super_vers = HDF5_SUPERBLOCK_VERSION_1;
 
-    /* Upgrade to the version indicated by the file's low bound if higher */
+    /* Finalize superblock version to that allowed by the file's low bound if higher */
     super_vers = MAX(super_vers, HDF5_superblock_ver_bounds[f->shared->low_bound]);
 
-    /* File bound check */
+    /* Version bounds check */
     if(super_vers > HDF5_superblock_ver_bounds[f->shared->high_bound])
         HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "superblock version out of bounds")
 
@@ -1091,8 +1144,8 @@ H5F__super_init(H5F_t *f, hid_t dxpl_id)
 
     /* Sanity check the userblock size vs. the file's allocation alignment */
     if(userblock_size > 0) {
-	/* Set up the alignment to use for page or aggr fs */
-	hsize_t alignment = H5F_PAGED_AGGR(f) ? f->shared->fs_page_size : f->shared->alignment;
+        /* Set up the alignment to use for page or aggr fs */
+        hsize_t alignment = H5F_PAGED_AGGR(f) ? f->shared->fs_page_size : f->shared->alignment;
 
         if(userblock_size < alignment)
             HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "userblock size must be > file object alignment")
diff --git a/src/H5Gobj.c b/src/H5Gobj.c
index 832c9a7..5f9bdc8 100644
--- a/src/H5Gobj.c
+++ b/src/H5Gobj.c
@@ -185,7 +185,7 @@ H5G__obj_create_real(H5F_t *f, hid_t dxpl_id, const H5O_ginfo_t *ginfo,
     H5G_obj_create_t *gcrt_info, H5O_loc_t *oloc/*out*/)
 {
     size_t hdr_size;                    /* Size of object header to request */
-    hbool_t use_v18_latest_format;      /* Flag indicating the new group format should be used */
+    hbool_t use_at_least_v18;           /* Flag indicating the new group format should be used */
     hid_t gcpl_id = gcrt_info->gcpl_id; /* Group creation property list ID */
     herr_t ret_value = SUCCEED;         /* Return value */
 
@@ -204,12 +204,12 @@ H5G__obj_create_real(H5F_t *f, hid_t dxpl_id, const H5O_ginfo_t *ginfo,
     if(0 == (H5F_INTENT(f) & H5F_ACC_RDWR))
         HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "no write intent on file")
 
-    /* Check for using the latest version of the group format */
+    /* Check for using the latest version of the group format which is introduced in v18 */
     /* (add more checks for creating "new format" groups when needed) */
     if((H5F_LOW_BOUND(f) >= H5F_LIBVER_V18) || linfo->track_corder || (pline && pline->nused))
-        use_v18_latest_format = TRUE;
+        use_at_least_v18 = TRUE;
     else
-        use_v18_latest_format = FALSE;
+        use_at_least_v18 = FALSE;
 
     /* Make certain that the creation order is being tracked if an index is
      *  going to be built on it.
@@ -218,7 +218,7 @@ H5G__obj_create_real(H5F_t *f, hid_t dxpl_id, const H5O_ginfo_t *ginfo,
         HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, FAIL, "must track creation order to create index for it")
 
     /* Check if we should be using the latest version of the group format */
-    if(use_v18_latest_format) {
+    if(use_at_least_v18) {
         H5O_link_t lnk;                     /* Temporary link message info for computing message size */
         char null_char = '\0';              /* Character for creating null string */
         size_t ginfo_size;                  /* Size of the group info message */
@@ -264,7 +264,7 @@ H5G__obj_create_real(H5F_t *f, hid_t dxpl_id, const H5O_ginfo_t *ginfo,
         HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "can't create header")
 
     /* Check for format of group to create */
-    if(use_v18_latest_format) {
+    if(use_at_least_v18) {
         /* Insert link info message */
         /* (Casting away const OK - QAK) */
         if(H5O_msg_create(oloc, H5O_LINFO_ID, 0, H5O_UPDATE_TIME, (void *)linfo, dxpl_id) < 0)
diff --git a/src/H5Oattr.c b/src/H5Oattr.c
index 5c45e82..773a16b 100644
--- a/src/H5Oattr.c
+++ b/src/H5Oattr.c
@@ -635,6 +635,8 @@ H5O_attr_pre_copy_file(H5F_t H5_ATTR_UNUSED *file_src, const void *native_src,
     HDassert(cpy_info);
     HDassert(cpy_info->file_dst);
 
+    /* Check to ensure that the version of the message to be copied does not exceed
+       the message version allowed by the destination file's high bound */
     if(attr_src->shared->version > H5O_attr_ver_bounds[H5F_HIGH_BOUND(cpy_info->file_dst)])
         HGOTO_ERROR(H5E_OHDR, H5E_BADRANGE, FAIL, "attribute message version out of bounds")
 
diff --git a/src/H5Ocopy.c b/src/H5Ocopy.c
index aa26f05..74c02f4 100644
--- a/src/H5Ocopy.c
+++ b/src/H5Ocopy.c
@@ -416,6 +416,7 @@ H5O_copy_header_real(const H5O_loc_t *oloc_src, H5O_loc_t *oloc_dst /*out*/,
     /* Initialize header information */
     oh_dst->version = oh_src->version;
 
+    /* Version bounds check for destination object header */
     if(oh_dst->version > H5O_obj_ver_bounds[H5F_HIGH_BOUND(oloc_dst->file)])
         HGOTO_ERROR(H5E_OHDR, H5E_BADRANGE, FAIL, "destination object header version out of bounds")
 
@@ -494,7 +495,12 @@ H5O_copy_header_real(const H5O_loc_t *oloc_src, H5O_loc_t *oloc_dst /*out*/,
             /* Decode the message if necessary. */
             H5O_LOAD_NATIVE(oloc_src->file, dxpl_id, 0, oh_src, mesg_src, FAIL)
 
+            /* Save destination file pointer in cpy_info so that it can be used
+               in the pre_copy_file callback to obtain the destination file's
+               high bound.  The high bound is used to index into the corresponding
+               message's array of versions for doing version bounds check. */
             cpy_info->file_dst = oloc_dst->file;
+
             /* Perform "pre copy" operation on message */
             if((copy_type->pre_copy_file)(oloc_src->file, mesg_src->native,
                     &(deleted[mesgno]), cpy_info, cpy_udata) < 0)
diff --git a/src/H5Odtype.c b/src/H5Odtype.c
index f6331df..c51e31d 100644
--- a/src/H5Odtype.c
+++ b/src/H5Odtype.c
@@ -1531,6 +1531,8 @@ H5O_dtype_pre_copy_file(H5F_t *file_src, const void *mesg_src,
     HDassert(cpy_info);
     HDassert(cpy_info->file_dst);
 
+    /* Check to ensure that the version of the message to be copied does not exceed
+       the message version as indicated by the destination file's high bound */
     if(dt_src->shared->version > H5O_dtype_ver_bounds[H5F_HIGH_BOUND(cpy_info->file_dst)])
         HGOTO_ERROR(H5E_OHDR, H5E_BADRANGE, FAIL, "datatype message version out of bounds")
 
diff --git a/src/H5Ofill.c b/src/H5Ofill.c
index cf64594..6dc3064 100644
--- a/src/H5Ofill.c
+++ b/src/H5Ofill.c
@@ -156,7 +156,7 @@ const H5O_msg_class_t H5O_MSG_FILL_NEW[1] = {{
 /* Format version bounds for fill value */
 const unsigned H5O_fill_ver_bounds[] = {
     H5O_FILL_VERSION_1,     /* H5F_LIBVER_EARLIEST */
-    H5O_FILL_VERSION_3,     /* H5F_LIBVER_V18 */
+    H5O_FILL_VERSION_2,     /* H5F_LIBVER_V18 */
     H5O_FILL_VERSION_LATEST /* H5F_LIBVER_LATEST */
 };
 
@@ -809,8 +809,7 @@ H5O_fill_free(void *fill)
  * Return:      Success:        Non-negative
  *              Failure:        Negative
  *
- * Programmer:  Quincey Koziol
- *              Friday, March  9, 2007
+ * Programmer:  Vailin Choi; Dec 2017
  *
  *-------------------------------------------------------------------------
  */
@@ -827,6 +826,8 @@ H5O_fill_pre_copy_file(H5F_t H5_ATTR_UNUSED *file_src, const void *mesg_src,
     HDassert(cpy_info);
     HDassert(cpy_info->file_dst);
 
+    /* Check to ensure that the version of the message to be copied does not exceed
+       the message version allowed by the destination file's high bound */
     if(fill_src->version > H5O_fill_ver_bounds[H5F_HIGH_BOUND(cpy_info->file_dst)])
         HGOTO_ERROR(H5E_OHDR, H5E_BADRANGE, FAIL, "fill value message version out of bounds")
 
@@ -1047,15 +1048,15 @@ done:
  *
  * Return:      Non-negative on success/Negative on failure
  *
- * Programmer:  Quincey Koziol
- *              Tuesday, July 24, 2007
+ * Programmer:  Vailin Choi; December 2017
  *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5O_fill_set_version(H5F_t *f, H5O_fill_t *fill)
 {
-    herr_t ret_value = SUCCEED;   /* Return value */
+    unsigned version;           /* Message version */
+    herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -1064,12 +1065,15 @@ H5O_fill_set_version(H5F_t *f, H5O_fill_t *fill)
     HDassert(fill);
 
     /* Upgrade to the version indicated by the file's low bound if higher */
-    fill->version = MAX(fill->version, H5O_fill_ver_bounds[H5F_LOW_BOUND(f)]);
+    version = MAX(fill->version, H5O_fill_ver_bounds[H5F_LOW_BOUND(f)]);
 
-    /* File bound check */
-    if(fill->version > H5O_fill_ver_bounds[H5F_HIGH_BOUND(f)])
+    /* Version bounds check */
+    if(version > H5O_fill_ver_bounds[H5F_HIGH_BOUND(f)])
         HGOTO_ERROR(H5E_OHDR, H5E_BADRANGE, FAIL, "Filter pipeline version out of bounds")
 
+    /* Set the message version */
+    fill->version = version;
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5O_fill_set_version() */
diff --git a/src/H5Oint.c b/src/H5Oint.c
index 0df7467..08eb28d 100644
--- a/src/H5Oint.c
+++ b/src/H5Oint.c
@@ -216,18 +216,17 @@ H5O__init_package(void)
  *              Chooses the oldest version possible, unless the file's
  *              low bound indicates otherwise.
  *
- * Return:	Success:    Non-negative
- *		    Failure:	Negative
+ * Return:  Success:    Non-negative
+ *          Failure:    Negative
  *
- * Programmer:  Quincey Koziol
- *              koziol@hdfgroup.org
- *              Jul 17 2007
+ * Programmer:  Vailin Choi; December 2017
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
 H5O_set_version(H5F_t *f, H5O_t *oh, uint8_t oh_flags, hbool_t store_msg_crt_idx)
 {
+    uint8_t version;            /* Message version */
     herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -238,17 +237,20 @@ H5O_set_version(H5F_t *f, H5O_t *oh, uint8_t oh_flags, hbool_t store_msg_crt_idx
 
     /* Set the correct version to encode object header with */
     if(store_msg_crt_idx || (oh_flags & H5O_HDR_ATTR_CRT_ORDER_TRACKED))
-        oh->version = H5O_VERSION_2;
+        version = H5O_VERSION_LATEST;
     else
-        oh->version = H5O_VERSION_1;
+        version = H5O_VERSION_1;
 
     /* Upgrade to the version indicated by the file's low bound if higher */
-    oh->version = MAX(oh->version, (uint8_t)H5O_obj_ver_bounds[H5F_LOW_BOUND(f)]);
+    version = MAX(version, (uint8_t)H5O_obj_ver_bounds[H5F_LOW_BOUND(f)]);
 
-    /* File bound check */
-    if(oh->version > H5O_obj_ver_bounds[H5F_HIGH_BOUND(f)])
+    /* Version bounds check */
+    if(version > H5O_obj_ver_bounds[H5F_HIGH_BOUND(f)])
         HGOTO_ERROR(H5E_OHDR, H5E_BADRANGE, FAIL, "object header version out of bounds")
 
+    /* Set the message version */
+    oh->version = version;
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5O_set_version() */
diff --git a/src/H5Olayout.c b/src/H5Olayout.c
index 3745f6d..85d7791 100644
--- a/src/H5Olayout.c
+++ b/src/H5Olayout.c
@@ -1055,8 +1055,7 @@ done:
  * Return:      Success:        Non-negative
  *              Failure:        Negative
  *
- * Programmer:  Quincey Koziol
- *              Friday, March  9, 2007
+ * Programmer:  Vailin Choi; Dec 2017
  *
  *-------------------------------------------------------------------------
  */
@@ -1073,6 +1072,8 @@ H5O__layout_pre_copy_file(H5F_t H5_ATTR_UNUSED *file_src, const void *mesg_src,
     HDassert(cpy_info);
     HDassert(cpy_info->file_dst);
 
+    /* Check to ensure that the version of the message to be copied does not exceed
+       the message version allowed by the destination file's high bound */
     if(layout_src->version > H5O_layout_ver_bounds[H5F_HIGH_BOUND(cpy_info->file_dst)])
         HGOTO_ERROR(H5E_OHDR, H5E_BADRANGE, FAIL, "layout message version out of bounds")
 
diff --git a/src/H5Opkg.h b/src/H5Opkg.h
index 13e0e3e..498938a 100644
--- a/src/H5Opkg.h
+++ b/src/H5Opkg.h
@@ -63,8 +63,8 @@
     )
 #define H5O_ALIGN_OH(O, X)						      \
      H5O_ALIGN_VERS((O)->version, X)
-#define H5O_ALIGN_F(F, X)						      \
-     H5O_ALIGN_VERS(((H5F_LOW_BOUND(F) >= H5F_LIBVER_V18) ? H5O_VERSION_LATEST : H5O_VERSION_1), X)
+#define H5O_ALIGN_F(F, X)                             \
+     H5O_ALIGN_VERS(MAX(H5O_VERSION_1, (uint8_t)H5O_obj_ver_bounds[H5F_LOW_BOUND(F)]), X)
 
 /* Size of checksum (on disk) */
 #define H5O_SIZEOF_CHKSUM               4
@@ -136,7 +136,7 @@
 #define H5O_SIZEOF_MSGHDR_OH(O)						      \
     H5O_SIZEOF_MSGHDR_VERS((O)->version, (O)->flags & H5O_HDR_ATTR_CRT_ORDER_TRACKED)
 #define H5O_SIZEOF_MSGHDR_F(F, C)						      \
-    H5O_SIZEOF_MSGHDR_VERS(((H5F_LOW_BOUND(F) >= H5F_LIBVER_V18) || H5F_STORE_MSG_CRT_IDX(F)) ? H5O_VERSION_LATEST : H5O_VERSION_1, (C))
+    H5O_SIZEOF_MSGHDR_VERS(MAX((H5F_STORE_MSG_CRT_IDX(F) ? H5O_VERSION_LATEST : H5O_VERSION_1), (uint8_t)H5O_obj_ver_bounds[H5F_LOW_BOUND(F)]), (C))
 
 /*
  * Size of chunk "header" for each chunk
@@ -641,6 +641,8 @@ H5_DLL herr_t H5O_attr_link(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh, void *_mesg
 H5_DLL herr_t H5O_attr_count_real(H5F_t *f, hid_t dxpl_id, H5O_t *oh,
     hsize_t *nattrs);
 
+/* Arrays of versions for:
+   Object header, Layout/Attribute/Datatype/Fill value/Filter pipeline/Dataspace messages */
 H5_DLLVAR const unsigned H5O_obj_ver_bounds[H5F_LIBVER_NBOUNDS];
 H5_DLLVAR const unsigned H5O_layout_ver_bounds[H5F_LIBVER_NBOUNDS];
 H5_DLLVAR const unsigned H5O_attr_ver_bounds[H5F_LIBVER_NBOUNDS];
diff --git a/src/H5Opline.c b/src/H5Opline.c
index ea913da..e817f9a 100644
--- a/src/H5Opline.c
+++ b/src/H5Opline.c
@@ -576,7 +576,7 @@ H5O_pline_pre_copy_file(H5F_t H5_ATTR_UNUSED *file_src, const void *mesg_src,
 {
     const H5O_pline_t *pline_src = (const H5O_pline_t *)mesg_src;    /* Source pline */
     H5O_copy_file_ud_common_t *udata = (H5O_copy_file_ud_common_t *)_udata; /* Object copying user data */
-    herr_t             ret_value = SUCCEED;                     /* Return value */
+    herr_t ret_value = SUCCEED;                                     /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
 
@@ -585,6 +585,8 @@ H5O_pline_pre_copy_file(H5F_t H5_ATTR_UNUSED *file_src, const void *mesg_src,
     HDassert(cpy_info);
     HDassert(cpy_info->file_dst);
 
+    /* Check to ensure that the version of the message to be copied does not exceed
+       the message version allowed by the destination file's high bound */
     if(pline_src->version > H5O_pline_ver_bounds[H5F_HIGH_BOUND(cpy_info->file_dst)])
         HGOTO_ERROR(H5E_OHDR, H5E_BADRANGE, FAIL, "pline message version out of bounds")
 
@@ -681,15 +683,15 @@ H5O_pline_debug(H5F_t H5_ATTR_UNUSED *f, hid_t H5_ATTR_UNUSED dxpl_id, const voi
  *
  * Return:      Non-negative on success/Negative on failure
  *
- * Programmer:  Quincey Koziol
- *              Tuesday, July 24, 2007
+ * Programmer:  Vailin Choi; December 2017
  *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5O_pline_set_version(H5F_t *f, H5O_pline_t *pline)
 {
-    herr_t ret_value = SUCCEED;   /* Return value */
+    unsigned version;           /* Message version */
+    herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -698,12 +700,15 @@ H5O_pline_set_version(H5F_t *f, H5O_pline_t *pline)
     HDassert(pline);
 
     /* Upgrade to the version indicated by the file's low bound if higher */
-    pline->version = MAX(pline->version, H5O_pline_ver_bounds[H5F_LOW_BOUND(f)]);
+    version = MAX(pline->version, H5O_pline_ver_bounds[H5F_LOW_BOUND(f)]);
 
-    /* File bound check */
-    if(pline->version > H5O_pline_ver_bounds[H5F_HIGH_BOUND(f)])
+    /* Version bounds check */
+    if(version > H5O_pline_ver_bounds[H5F_HIGH_BOUND(f)])
         HGOTO_ERROR(H5E_PLINE, H5E_BADRANGE, FAIL, "Filter pipeline version out of bounds")
 
+    /* Set the message version */
+    pline->version = version;
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5O_pline_set_version() */
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 5cf9dce..2253bb2 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -178,7 +178,11 @@ typedef struct H5O_copy_t {
     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 */
     H5F_t   *file_dst;                  /* The destination file pointer */
-    void    *shared_fo;                 /* The shared pointer for the object */
+                                        /* This is used in the pre_copy_file callback to obtain
+                                           the destination file's high bound.  The high bound
+                                           is used to index into the corresponding message's
+                                           array of versions for doing version bounds check. */
+    void    *shared_fo;                 /* The shared pointer for the src 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/src/H5Osdspace.c b/src/H5Osdspace.c
index 9a9d020..12a9bb6 100644
--- a/src/H5Osdspace.c
+++ b/src/H5Osdspace.c
@@ -455,6 +455,8 @@ H5O_sdspace_pre_copy_file(H5F_t H5_ATTR_UNUSED *file_src, const void *mesg_src,
     HDassert(cpy_info);
     HDassert(cpy_info->file_dst);
 
+    /* Check to ensure that the version of the message to be copied does not exceed
+       the message version allowed by the destination file's high bound */
     if(src_space_extent->version > H5O_sdspace_ver_bounds[H5F_HIGH_BOUND(cpy_info->file_dst)])
         HGOTO_ERROR(H5E_OHDR, H5E_BADRANGE, FAIL, "dataspace message version out of bounds")
 
diff --git a/src/H5S.c b/src/H5S.c
index 8046357..8f3e132 100644
--- a/src/H5S.c
+++ b/src/H5S.c
@@ -2180,15 +2180,15 @@ H5S_extent_nelem(const H5S_extent_t *ext)
  *
  * Return:      Non-negative on success/Negative on failure
  *
- * Programmer:  Quincey Koziol
- *              Tuesday, July 24, 2007
+ * Programmer:  Vailin Choi; December 2017
  *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5S_set_version(H5F_t *f, H5S_t *ds)
 {
-    herr_t ret_value = SUCCEED;   /* Return value */
+    unsigned version;           /* Message version */
+    herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -2197,12 +2197,15 @@ H5S_set_version(H5F_t *f, H5S_t *ds)
     HDassert(ds);
 
     /* Upgrade to the version indicated by the file's low bound if higher */
-    ds->extent.version = MAX(ds->extent.version, H5O_sdspace_ver_bounds[H5F_LOW_BOUND(f)]);
+    version = MAX(ds->extent.version, H5O_sdspace_ver_bounds[H5F_LOW_BOUND(f)]);
 
-    /* File bound check */
-    if(ds->extent.version > H5O_sdspace_ver_bounds[H5F_HIGH_BOUND(f)])
+    /* Version bounds check */
+    if(version > H5O_sdspace_ver_bounds[H5F_HIGH_BOUND(f)])
         HGOTO_ERROR(H5E_DATASET, H5E_BADRANGE, FAIL, "Dataspace version out of bounds")
 
+    /* Set the message version */
+    ds->extent.version = version;
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 
diff --git a/src/H5T.c b/src/H5T.c
index aa61358..eca0132 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -5418,8 +5418,7 @@ done:
  *
  * Return:      Non-negative on success/Negative on failure
  *
- * Programmer:  Quincey Koziol
- *              Thursday, July 19, 2007
+ * Programmer:  Vailin Choi; December 2017
  *
  *-------------------------------------------------------------------------
  */
@@ -5442,7 +5441,7 @@ H5T_set_version(H5F_t *f, H5T_t *dt)
             HGOTO_ERROR(H5E_DATATYPE, H5E_CANTSET, FAIL, "can't upgrade datatype encoding")
     }
     
-    /* File bound check */
+    /* Version bounds check */
     if(dt->shared->version > H5O_dtype_ver_bounds[H5F_HIGH_BOUND(f)])
         HGOTO_ERROR(H5E_DATATYPE, H5E_BADRANGE, FAIL, "Datatype version out of bounds")
 
diff --git a/src/H5trace.c b/src/H5trace.c
index 5f8ccd1..b1f05ba 100644
--- a/src/H5trace.c
+++ b/src/H5trace.c
@@ -1021,7 +1021,8 @@ H5_trace(const double *returning, const char *func, const char *type, ...)
                                     fprintf(out, "H5F_LIBVER_V18");
                                     break;
 
-                                case H5F_LIBVER_LATEST:
+                                case H5F_LIBVER_V110:
+                                    HDassert(H5F_LIBVER_LATEST == H5F_LIBVER_V110);
                                     fprintf(out, "H5F_LIBVER_LATEST");
                                     break;