[svn-r13361] Description:

	Add H5Aopen(), H5Aopen_by_idx() and H5Acreate2() routines.

Tested on:
	Mac OS X/32 10.4.8 (amazon)

5 files changed, 620 insertions, 119 deletions

diff --git a/src/H5A.c b/src/H5A.c
index 3484d45e..5730353 100644
--- a/src/H5A.c
+++ b/src/H5A.c
@@ -66,11 +66,7 @@ typedef struct H5A_iter_cb1 {
 /* Local Prototypes */
 /********************/
 
-static hid_t H5A_create(const H5G_loc_t *loc, const char *name,
-    const H5T_t *type, const H5S_t *space, hid_t acpl_id, hid_t dxpl_id);
 static herr_t H5A_open_common(const H5G_loc_t *loc, H5A_t *attr);
-static H5A_t *H5A_open_by_name(const H5G_loc_t *loc, const char *obj_name,
-    const char *attr_name, hid_t lapl_id, hid_t dxpl_id);
 static herr_t H5A_write(H5A_t *attr, const H5T_t *mem_type, const void *buf, hid_t dxpl_id);
 static herr_t H5A_read(const H5A_t *attr, const H5T_t *mem_type, void *buf, hid_t dxpl_id);
 static hsize_t H5A_get_storage_size(const H5A_t *attr);
@@ -191,49 +187,50 @@ H5A_term_interface(void)
 
 /*--------------------------------------------------------------------------
  NAME
-    H5Acreate
+    H5Acreate2
  PURPOSE
-    Creates a dataset as an attribute of another dataset or group
+    Creates an attribute on an object
  USAGE
-    hid_t H5Acreate (loc_id, name, type_id, space_id, plist_id)
+    hid_t H5Acreate2(loc_id, obj_name, attr_name, type_id, space_id, acpl_id,
+            aapl_id, lapl_id)
         hid_t loc_id;       IN: Object (dataset or group) to be attached to
-        const char *name;   IN: Name of attribute to create
-        hid_t type_id;      IN: ID of datatype for attribute
-        hid_t space_id;     IN: ID of dataspace for attribute
-        hid_t plist_id;     IN: ID of creation property list (currently not used)
+        const char *obj_name;   IN: Name of object relative to location
+        const char *attr_name;  IN: Name of attribute to locate and open
+        hid_t type_id;          IN: ID of datatype for attribute
+        hid_t space_id;         IN: ID of dataspace for attribute
+        hid_t acpl_id;          IN: ID of creation property list (currently not used)
+        hid_t aapl_id;          IN: Attribute access property list
+        hid_t lapl_id;          IN: Link access property list
  RETURNS
     Non-negative on success/Negative on failure
 
  DESCRIPTION
         This function creates an attribute which is attached to the object
-    specified with 'location_id'.  The name specified with 'name' for each
-    attribute for an object must be unique for that object.  The 'type_id'
+    specified with 'loc_id/obj_name'.  The name specified with 'attr_name' for
+    each attribute for an object must be unique for that object.  The 'type_id'
     and 'space_id' are created with the H5T and H5S interfaces respectively.
-    Currently only simple dataspaces are allowed for attribute dataspaces.
-    The 'plist_id' property list is currently un-used, but will be
-    used int the future for optional properties of attributes.  The attribute
-    ID returned from this function must be released with H5Aclose or resource
-    leaks will develop.
-        The link created (see H5G API documentation for more information on
-    link types) is a hard link, so the attribute may be shared among datasets
-    and will not be removed from the file until the reference count for the
-    attribute is reduced to zero.
-        The location object may be either a group or a dataset, both of
-    which may have any sort of attribute.
+    The 'aapl_id' property list is currently unused, but will be used in the
+    future for optional attribute access properties.  The attribute ID returned
+    from this function must be released with H5Aclose or resource leaks will
+    develop.
 
 --------------------------------------------------------------------------*/
 /* ARGSUSED */
 hid_t
-H5Acreate(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
-	  hid_t plist_id)
+H5Acreate2(hid_t loc_id, const char *obj_name, const char *attr_name,
+    hid_t type_id, hid_t space_id, hid_t acpl_id, hid_t UNUSED aapl_id,
+    hid_t lapl_id)
 {
     H5G_loc_t           loc;                    /* Object location */
+    H5G_loc_t           obj_loc;                /* Location used to open group */
+    H5G_name_t          obj_path;            	/* Opened object group hier. path */
+    H5O_loc_t           obj_oloc;            	/* Opened object object location */
+    hbool_t             loc_found = FALSE;      /* Entry at 'obj_name' found */
     H5T_t		*type;                  /* Datatype to use for attribute */
     H5S_t		*space;                 /* Dataspace to use for attribute */
     hid_t		ret_value;              /* Return value */
 
-    FUNC_ENTER_API(H5Acreate, FAIL)
-    H5TRACE5("i", "isiii", loc_id, name, type_id, space_id, plist_id);
+    FUNC_ENTER_API(H5Acreate2, FAIL)
 
     /* check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
@@ -242,20 +239,36 @@ H5Acreate(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(0 == (H5F_INTENT(loc.oloc->file) & H5F_ACC_RDWR))
 	HGOTO_ERROR(H5E_ARGS, H5E_WRITEERROR, FAIL, "no write intent on file")
-    if(!name || !*name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+    if(!obj_name || !*obj_name)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
+    if(!attr_name || !*attr_name)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
     if(NULL == (type = (H5T_t *)H5I_object_verify(type_id, H5I_DATATYPE)))
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a type")
     if(NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space")
 
+    /* Set up opened group location to fill in */
+    obj_loc.oloc = &obj_oloc;
+    obj_loc.path = &obj_path;
+    H5G_loc_reset(&obj_loc);
+
+    /* Find the object's location */
+    if(H5G_loc_find(&loc, obj_name, &obj_loc/*out*/, lapl_id, H5AC_ind_dxpl_id) < 0)
+        HGOTO_ERROR(H5E_ATTR, H5E_NOTFOUND, FAIL, "object not found")
+    loc_found = TRUE;
+
     /* Go do the real work for attaching the attribute to the dataset */
-    if((ret_value = H5A_create(&loc, name, type, space, plist_id, H5AC_dxpl_id)) < 0)
+    if((ret_value = H5A_create(&obj_loc, attr_name, type, space, acpl_id, H5AC_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to create attribute")
 
 done:
+    /* Release resources */
+    if(loc_found && H5G_loc_free(&obj_loc) < 0)
+        HDONE_ERROR(H5E_ATTR, H5E_CANTRELEASE, FAIL, "can't free location")
+
     FUNC_LEAVE_API(ret_value)
-} /* H5Acreate() */
+} /* H5Acreate2() */
 
 
 /*-------------------------------------------------------------------------
@@ -276,17 +289,9 @@ done:
  * Programmer:	Quincey Koziol
  *		April 2, 1998
  *
- * Modifications:
- *
- *	 Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
- *	 Added a deep copy of the symbol table entry
- *
- *       James Laird, <jlaird@ncsa.uiuc.edu> 9 Nov 2005
- *       Added Attribute Creation Property List
- *
  *-------------------------------------------------------------------------
  */
-static hid_t
+hid_t
 H5A_create(const H5G_loc_t *loc, const char *name, const H5T_t *type,
     const H5S_t *space, hid_t acpl_id, hid_t dxpl_id)
 {
@@ -416,13 +421,16 @@ done:
 
 /*--------------------------------------------------------------------------
  NAME
-    H5Aopen_name
+    H5Aopen
  PURPOSE
     Opens an attribute for an object by looking up the attribute name
  USAGE
-    hid_t H5Aopen_name (loc_id, name)
-        hid_t loc_id;       IN: Object (dataset or group) to be attached to
-        const char *name;   IN: Name of attribute to locate and open
+    hid_t H5Aopen(loc_id, obj_name, attr_name, aapl_id, lapl_id)
+        hid_t loc_id;           IN: Object that attribute is attached to
+        const char *obj_name;   IN: Name of object relative to location
+        const char *attr_name;  IN: Name of attribute to locate and open
+        hid_t aapl_id;          IN: Attribute access property list
+        hid_t lapl_id;          IN: Link access property list
  RETURNS
     ID of attribute on success, negative on failure
 
@@ -431,29 +439,34 @@ done:
     name specified is used to look up the corresponding attribute for the
     object.  The attribute ID returned from this function must be released with
     H5Aclose or resource leaks will develop.
-        The location object may be either a group or a dataset, both of
-    which may have any sort of attribute.
 --------------------------------------------------------------------------*/
 hid_t
-H5Aopen_name(hid_t loc_id, const char *name)
+H5Aopen(hid_t loc_id, const char *obj_name, const char *attr_name,
+    hid_t UNUSED aapl_id, hid_t lapl_id)
 {
     H5G_loc_t    	loc;            /* Object location */
     H5A_t               *attr = NULL;   /* Attribute opened */
     hid_t		ret_value;
 
-    FUNC_ENTER_API(H5Aopen_name, FAIL)
-    H5TRACE2("i", "is", loc_id, name);
+    FUNC_ENTER_API(H5Aopen, FAIL)
 
     /* check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!name || !*name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+    if(!obj_name || !*obj_name)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
+    if(!attr_name || !*attr_name)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
+    if(H5P_DEFAULT == lapl_id)
+        lapl_id = H5P_LINK_ACCESS_DEFAULT;
+    else
+        if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
     /* Open the attribute on the object header */
-    if(NULL == (attr = H5A_open_by_name(&loc, ".", name, H5P_LINK_ACCESS_DEFAULT, H5AC_ind_dxpl_id)))
+    if(NULL == (attr = H5A_open_by_name(&loc, obj_name, attr_name, lapl_id, H5AC_ind_dxpl_id)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
 
     /* Register the attribute and get an ID for it */
@@ -467,7 +480,7 @@ done:
             HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
 
     FUNC_LEAVE_API(ret_value)
-} /* H5Aopen_name() */
+} /* H5Aopen() */
 
 
 /*--------------------------------------------------------------------------
@@ -673,7 +686,7 @@ done:
  *
  *-------------------------------------------------------------------------
  */
-static H5A_t *
+H5A_t *
 H5A_open_by_name(const H5G_loc_t *loc, const char *obj_name, const char *attr_name,
     hid_t lapl_id, hid_t dxpl_id)
 {
@@ -1401,14 +1414,48 @@ H5A_get_storage_size(const H5A_t *attr)
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Aget_info(hid_t loc_id, const char *obj_name, const char *attr_name,
+H5Aget_info(hid_t attr_id, H5A_info_t *ainfo)
+{
+    H5A_t	*attr;                  /* Attribute object for name */
+    herr_t	ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_API(H5Aget_info, FAIL)
+
+    /* Check args */
+    if(NULL == (attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
+
+    /* Get the attribute information */
+    if(H5A_get_info(attr, ainfo) < 0)
+	HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Aget_info() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Aget_info_by_name
+ *
+ * Purpose:	Retrieve information about an attribute by name.
+ *
+ * Return:	Success:	Non-negative
+ *		Failure:	Negative
+ *
+ * Programmer:	Quincey Koziol
+ *              February  6, 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Aget_info_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     H5A_info_t *ainfo, hid_t lapl_id)
 {
     H5G_loc_t   loc;                    /* Object location */
     H5A_t	*attr = NULL;           /* Attribute object for name */
     herr_t	ret_value = SUCCEED;    /* Return value */
 
-    FUNC_ENTER_API(H5Aget_info, FAIL)
+    FUNC_ENTER_API(H5Aget_info_by_name, FAIL)
 
     /* Check args */
     if(H5I_ATTR == H5I_get_type(loc_id))
@@ -1441,7 +1488,7 @@ done:
         HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
 
     FUNC_LEAVE_API(ret_value)
-} /* end H5Aget_info() */
+} /* end H5Aget_info_by_name() */
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Adeprec.c b/src/H5Adeprec.c
index 9b49b81..b235a5c 100644
--- a/src/H5Adeprec.c
+++ b/src/H5Adeprec.c
@@ -108,6 +108,121 @@ H5A_init_deprec_interface(void)
 
 /*--------------------------------------------------------------------------
  NAME
+    H5Acreate
+ PURPOSE
+    Creates an attribute on an object
+ USAGE
+    hid_t H5Acreate (loc_id, name, type_id, space_id, plist_id)
+        hid_t loc_id;       IN: Object (dataset or group) to be attached to
+        const char *name;   IN: Name of attribute to create
+        hid_t type_id;      IN: ID of datatype for attribute
+        hid_t space_id;     IN: ID of dataspace for attribute
+        hid_t plist_id;     IN: ID of creation property list (currently not used)
+ RETURNS
+    Non-negative on success/Negative on failure
+
+ DESCRIPTION
+        This function creates an attribute which is attached to the object
+    specified with 'location_id'.  The name specified with 'name' for each
+    attribute for an object must be unique for that object.  The 'type_id'
+    and 'space_id' are created with the H5T and H5S interfaces respectively.
+    The attribute ID returned from this function must be released with H5Aclose
+    or resource leaks will develop.
+
+--------------------------------------------------------------------------*/
+hid_t
+H5Acreate(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
+	  hid_t plist_id)
+{
+    H5G_loc_t           loc;                    /* Object location */
+    H5T_t		*type;                  /* Datatype to use for attribute */
+    H5S_t		*space;                 /* Dataspace to use for attribute */
+    hid_t		ret_value;              /* Return value */
+
+    FUNC_ENTER_API(H5Acreate, FAIL)
+    H5TRACE5("i", "isiii", loc_id, name, type_id, space_id, plist_id);
+
+    /* check arguments */
+    if(H5I_ATTR == H5I_get_type(loc_id))
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+    if(H5G_loc(loc_id, &loc) < 0)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+    if(0 == (H5F_INTENT(loc.oloc->file) & H5F_ACC_RDWR))
+	HGOTO_ERROR(H5E_ARGS, H5E_WRITEERROR, FAIL, "no write intent on file")
+    if(!name || !*name)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+    if(NULL == (type = (H5T_t *)H5I_object_verify(type_id, H5I_DATATYPE)))
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a type")
+    if(NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space")
+
+    /* Go do the real work for attaching the attribute to the dataset */
+    if((ret_value = H5A_create(&loc, name, type, space, plist_id, H5AC_dxpl_id)) < 0)
+	HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to create attribute")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Acreate() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
+    H5Aopen_name
+ PURPOSE
+    Opens an attribute for an object by looking up the attribute name
+ USAGE
+    hid_t H5Aopen_name (loc_id, name)
+        hid_t loc_id;       IN: Object (dataset or group) to be attached to
+        const char *name;   IN: Name of attribute to locate and open
+ RETURNS
+    ID of attribute on success, negative on failure
+
+ DESCRIPTION
+        This function opens an existing attribute for access.  The attribute
+    name specified is used to look up the corresponding attribute for the
+    object.  The attribute ID returned from this function must be released with
+    H5Aclose or resource leaks will develop.
+        The location object may be either a group or a dataset, both of
+    which may have any sort of attribute.
+--------------------------------------------------------------------------*/
+hid_t
+H5Aopen_name(hid_t loc_id, const char *name)
+{
+    H5G_loc_t    	loc;            /* Object location */
+    H5A_t               *attr = NULL;   /* Attribute opened */
+    hid_t		ret_value;
+
+    FUNC_ENTER_API(H5Aopen_name, FAIL)
+    H5TRACE2("i", "is", loc_id, name);
+
+    /* check arguments */
+    if(H5I_ATTR == H5I_get_type(loc_id))
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+    if(H5G_loc(loc_id, &loc) < 0)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+    if(!name || !*name)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+
+    /* Open the attribute on the object header */
+    if(NULL == (attr = H5A_open_by_name(&loc, ".", name, H5P_LINK_ACCESS_DEFAULT, H5AC_ind_dxpl_id)))
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
+
+    /* Register the attribute and get an ID for it */
+    if((ret_value = H5I_register(H5I_ATTR, attr)) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register attribute for ID")
+
+done:
+    /* Cleanup on failure */
+    if(ret_value < 0)
+        if(attr && H5A_close(attr) < 0)
+            HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+
+    FUNC_LEAVE_API(ret_value)
+} /* H5Aopen_name() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
     H5Aopen_idx
  PURPOSE
     Opens the n'th attribute for an object
diff --git a/src/H5Apkg.h b/src/H5Apkg.h
index c7d5ba3..59a2032 100644
--- a/src/H5Apkg.h
+++ b/src/H5Apkg.h
@@ -171,6 +171,10 @@ H5_DLLVAR const H5B2_class_t H5A_BT2_CORDER[1];
 
 /* Function prototypes for H5A package scope */
 H5_DLL herr_t H5A_init(void);
+H5_DLL hid_t H5A_create(const H5G_loc_t *loc, const char *name,
+    const H5T_t *type, const H5S_t *space, hid_t acpl_id, hid_t dxpl_id);
+H5_DLL H5A_t * H5A_open_by_name(const H5G_loc_t *loc, const char *obj_name,
+    const char *attr_name, hid_t lapl_id, hid_t dxpl_id);
 H5_DLL H5A_t *H5A_open_by_idx(const H5G_loc_t *loc, const char *obj_name,
     H5_index_t idx_type, H5_iter_order_t order, hsize_t n, hid_t lapl_id, hid_t dxpl_id);
 H5_DLL H5A_t *H5A_copy(H5A_t *new_attr, const H5A_t *old_attr);
diff --git a/src/H5Apublic.h b/src/H5Apublic.h
index cde9bc6..3a440a9 100644
--- a/src/H5Apublic.h
+++ b/src/H5Apublic.h
@@ -45,9 +45,10 @@ typedef herr_t (*H5A_operator2_t)(hid_t location_id/*in*/,
     const char *attr_name/*in*/, const H5A_info_t *ainfo/*in*/, void *op_data/*in,out*/);
 
 /* Public function prototypes */
-H5_DLL hid_t   H5Acreate(hid_t loc_id, const char *name, hid_t type_id,
-    hid_t space_id, hid_t plist_id);
-H5_DLL hid_t   H5Aopen_name(hid_t loc_id, const char *name);
+H5_DLL hid_t   H5Acreate2(hid_t loc_id, const char *obj_name, const char *attr_name,
+    hid_t type_id, hid_t space_id, hid_t acpl_id, hid_t aapl_id, hid_t lapl_id);
+H5_DLL hid_t   H5Aopen(hid_t loc_id, const char *obj_name, const char *attr_name,
+    hid_t aapl_id, hid_t lapl_id);
 H5_DLL hid_t   H5Aopen_by_idx(hid_t loc_id, const char *obj_name, 
     H5_index_t idx_type, H5_iter_order_t order, hsize_t n, hid_t aapl_id,
     hid_t lapl_id);
@@ -62,7 +63,8 @@ H5_DLL ssize_t H5Aget_name_by_idx(hid_t loc_id, const char *obj_name,
     H5_index_t idx_type, H5_iter_order_t order, hsize_t n,
     char *name /*out*/, size_t size, hid_t lapl_id);
 H5_DLL hsize_t H5Aget_storage_size(hid_t attr_id);
-H5_DLL herr_t  H5Aget_info(hid_t loc_id, const char *obj_name,
+H5_DLL herr_t  H5Aget_info(hid_t attr_id, H5A_info_t *ainfo /*out*/);
+H5_DLL herr_t  H5Aget_info_by_name(hid_t loc_id, const char *obj_name,
     const char *attr_name, H5A_info_t *ainfo /*out*/, hid_t lapl_id);
 H5_DLL herr_t  H5Aget_info_by_idx(hid_t loc_id, const char *obj_name,
     H5_index_t idx_type, H5_iter_order_t order, hsize_t n,
@@ -82,6 +84,9 @@ H5_DLL herr_t  H5Adelete_by_idx(hid_t loc_id, const char *obj_name,
  * 
  * Use of these functions and variables is deprecated.
  */
+H5_DLL hid_t   H5Acreate(hid_t loc_id, const char *name, hid_t type_id,
+    hid_t space_id, hid_t plist_id);
+H5_DLL hid_t   H5Aopen_name(hid_t loc_id, const char *name);
 H5_DLL hid_t   H5Aopen_idx(hid_t loc_id, unsigned idx);
 H5_DLL int     H5Aget_num_attrs(hid_t loc_id);
 H5_DLL herr_t  H5Arename(hid_t loc_id, const char *old_name, const char *new_name);
diff --git a/test/tattr.c b/test/tattr.c
index 26c2597..1cd3a2f 100644
--- a/test/tattr.c
+++ b/test/tattr.c
@@ -2982,12 +2982,12 @@ test_attr_corder_create_compact(hid_t fcpl, hid_t fapl)
 
             /* Retrieve information for attribute */
             sprintf(attrname, "attr %02u", u);
-            ret = H5Aget_info(my_dataset, ".", attrname, &ainfo, H5P_DEFAULT);
-            CHECK(ret, FAIL, "H5Aget_info");
+            ret = H5Aget_info_by_name(my_dataset, ".", attrname, &ainfo, H5P_DEFAULT);
+            CHECK(ret, FAIL, "H5Aget_info_by_name");
 
             /* Verify creation order of attribute */
-            VERIFY(ainfo.corder_valid, TRUE, "H5Aget_info");
-            VERIFY(ainfo.corder, u, "H5Aget_info");
+            VERIFY(ainfo.corder_valid, TRUE, "H5Aget_info_by_name");
+            VERIFY(ainfo.corder, u, "H5Aget_info_by_name");
         } /* end for */
     } /* end for */
 
@@ -3209,12 +3209,12 @@ test_attr_corder_create_dense(hid_t fcpl, hid_t fapl)
 
             /* Retrieve information for attribute */
             sprintf(attrname, "attr %02u", u);
-            ret = H5Aget_info(my_dataset, ".", attrname, &ainfo, H5P_DEFAULT);
-            CHECK(ret, FAIL, "H5Aget_info");
+            ret = H5Aget_info_by_name(my_dataset, ".", attrname, &ainfo, H5P_DEFAULT);
+            CHECK(ret, FAIL, "H5Aget_info_by_name");
 
             /* Verify creation order of attribute */
-            VERIFY(ainfo.corder_valid, TRUE, "H5Aget_info");
-            VERIFY(ainfo.corder, u, "H5Aget_info");
+            VERIFY(ainfo.corder_valid, TRUE, "H5Aget_info_by_name");
+            VERIFY(ainfo.corder, u, "H5Aget_info_by_name");
         } /* end for */
     } /* end for */
 
@@ -4748,7 +4748,7 @@ HDfprintf(stderr, "op_data->curr = %Hd\n", op_data->curr);
     op_data->ncalled++;
 
     /* Get the attribute information directly to compare */
-    if(H5Aget_info(loc_id, ".", attr_name, &my_info, H5P_DEFAULT) < 0)
+    if(H5Aget_info_by_name(loc_id, ".", attr_name, &my_info, H5P_DEFAULT) < 0)
         return(H5_ITER_ERROR);
 
     /* Check more things for revised attribute iteration (vs. older attribute iteration) */
@@ -4991,6 +4991,7 @@ attr_iterate_check(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
         return(-1);
 } /* end attr_iterate_check() */
 
+
 /****************************************************************
 **
 **  test_attr_iterate2(): Test basic H5A (attribute) code.
@@ -5258,8 +5259,72 @@ test_attr_iterate2(hbool_t new_format, hid_t fcpl, hid_t fapl)
     /* Close dataspace */
     ret = H5Sclose(sid);
     CHECK(ret, FAIL, "H5Sclose");
+
+    /* Free the "visited link" array */
+    HDfree(visited);
 }   /* test_attr_iterate2() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    attr_open_by_idx_check
+ *
+ * Purpose:     Check opening attribute by index on an object
+ *
+ * Return:      Success:        0
+ *              Failure:        -1
+ *
+ * Programmer:  Quincey Koziol
+ *              Wednesday, February 21, 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+attr_open_by_idx_check(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
+    unsigned max_attrs)
+{
+    hid_t       attr_id;        /* ID of attribute to test */
+    H5A_info_t  ainfo;          /* Attribute info */
+    int         old_nerrs;      /* Number of errors when entering this check */
+    unsigned    u;              /* Local index variable */
+    herr_t	ret;		/* Generic return value	*/
+
+    /* Retrieve the current # of reported errors */
+    old_nerrs = GetTestNumErrs();
+
+    /* Open each attribute on object by index and check that it's the correct one */
+    for(u = 0; u < max_attrs; u++) {
+        /* Open the attribute */
+        attr_id = H5Aopen_by_idx(obj_id, ".", idx_type, order, (hsize_t)u, H5P_DEFAULT, H5P_DEFAULT);
+        CHECK(attr_id, FAIL, "H5Aopen_by_idx");
+
+        /* Get the attribute's information */
+        ret = H5Aget_info(attr_id, &ainfo);
+        CHECK(ret, FAIL, "H5Aget_info");
+
+        /* Check that the object is the correct one */
+        if(order == H5_ITER_INC) {
+            VERIFY(ainfo.corder, u, "H5Aget_info");
+        } /* end if */
+        else if(order == H5_ITER_DEC) {
+            VERIFY(ainfo.corder, (max_attrs - (u + 1)), "H5Aget_info");
+        } /* end if */
+        else {
+            /* XXX: What to do about native order? */
+        } /* end else */
+
+        /* Close attribute */
+        ret = H5Aclose(attr_id);
+        CHECK(ret, FAIL, "H5Aclose");
+    } /* end for */
+
+    /* Retrieve current # of errors */
+    if(old_nerrs == GetTestNumErrs())
+        return(0);
+    else
+        return(-1);
+} /* end attr_open_by_idx_check() */
+
+
 /****************************************************************
 **
 **  test_attr_open_by_idx(): Test basic H5A (attribute) code.
@@ -5284,9 +5349,6 @@ test_attr_open_by_idx(hbool_t new_format, hid_t fcpl, hid_t fapl)
     hsize_t     corder_count;   /* # of records in creation order index */
     H5_index_t idx_type;        /* Type of index to operate on */
     H5_iter_order_t order;      /* Order within in the index */
-    attr_iter_info_t iter_info; /* Iterator info */
-    hbool_t     *visited = NULL;        /* Array of flags for visiting links */
-    hsize_t     idx;            /* Start index for iteration */
     hbool_t     use_index;      /* Use index on creation order values */
     char	attrname[NAME_BUF_SIZE];    /* Name of attribute */
     unsigned    curr_dset;      /* Current dataset to work on */
@@ -5305,12 +5367,6 @@ test_attr_open_by_idx(hbool_t new_format, hid_t fcpl, hid_t fapl)
     ret = H5Pget_attr_phase_change(dcpl, &max_compact, &min_dense);
     CHECK(ret, FAIL, "H5Pget_attr_phase_change");
 
-    /* Allocate the "visited link" array */
-    iter_info.max_visit = max_compact * 2;
-    visited = HDmalloc(sizeof(hbool_t) * iter_info.max_visit);
-    CHECK(visited, NULL, "HDmalloc");
-    iter_info.visited = visited;
-
     /* Loop over operating on different indices on link fields */
     for(idx_type = H5_INDEX_NAME; idx_type <=H5_INDEX_CRT_ORDER; idx_type++) {
         /* Loop over operating in different orders */
@@ -5321,29 +5377,29 @@ test_attr_open_by_idx(hbool_t new_format, hid_t fcpl, hid_t fapl)
                 if(idx_type == H5_INDEX_CRT_ORDER) {
                     if(order == H5_ITER_INC) {
                         if(use_index)
-                            MESSAGE(5, ("Testing Iterating over Attributes By Creation Order Index in Increasing Order w/Creation Order Index\n"))
+                            MESSAGE(5, ("Testing Opening Attributes By Creation Order Index in Increasing Order w/Creation Order Index\n"))
                         else
-                            MESSAGE(5, ("Testing Iterating over Attributes By Creation Order Index in Increasing Order w/o Creation Order Index\n"))
+                            MESSAGE(5, ("Testing Opening Attributes By Creation Order Index in Increasing Order w/o Creation Order Index\n"))
                     } /* end if */
                     else {
                         if(use_index)
-                            MESSAGE(5, ("Testing Iterating over Attributes By Creation Order Index in Decreasing Order w/Creation Order Index\n"))
+                            MESSAGE(5, ("Testing Opening Attributes By Creation Order Index in Decreasing Order w/Creation Order Index\n"))
                         else
-                            MESSAGE(5, ("Testing Iterating over Attributes By Creation Order Index in Decreasing Order w/o Creation Order Index\n"))
+                            MESSAGE(5, ("Testing Opening Attributes By Creation Order Index in Decreasing Order w/o Creation Order Index\n"))
                     } /* end else */
                 } /* end if */
                 else {
                     if(order == H5_ITER_INC) {
                         if(use_index)
-                            MESSAGE(5, ("Testing Iterating over Attributes By Name Index in Increasing Order w/Creation Order Index\n"))
+                            MESSAGE(5, ("Testing Opening Attributes By Name Index in Increasing Order w/Creation Order Index\n"))
                         else
-                            MESSAGE(5, ("Testing Iterating over Attributes By Name Index in Increasing Order w/o Creation Order Index\n"))
+                            MESSAGE(5, ("Testing Opening Attributes By Name Index in Increasing Order w/o Creation Order Index\n"))
                     } /* end if */
                     else {
                         if(use_index)
-                            MESSAGE(5, ("Testing Iterating over Attributes By Name Index in Decreasing Order w/Creation Order Index\n"))
+                            MESSAGE(5, ("Testing Opening Attributes By Name Index in Decreasing Order w/Creation Order Index\n"))
                         else
-                            MESSAGE(5, ("Testing Iterating over Attributes By Name Index in Decreasing Order w/o Creation Order Index\n"))
+                            MESSAGE(5, ("Testing Opening Attributes By Name Index in Decreasing Order w/o Creation Order Index\n"))
                     } /* end else */
                 } /* end else */
 
@@ -5388,9 +5444,9 @@ test_attr_open_by_idx(hbool_t new_format, hid_t fcpl, hid_t fapl)
                     is_dense = H5O_is_attr_dense_test(my_dataset);
                     VERIFY(is_dense, FALSE, "H5O_is_attr_dense_test");
 
-                    /* Check for iterating over object with no attributes (should be OK) */
-                    ret = H5Aiterate2(my_dataset, ".", idx_type, order, NULL, attr_iterate2_cb, NULL, H5P_DEFAULT);
-                    CHECK(ret, FAIL, "H5Aiterate2");
+                    /* Check for opening an attribute on an object with no attributes */
+                    ret = H5Aopen_by_idx(my_dataset, ".", idx_type, order, (hsize_t)0, H5P_DEFAULT, H5P_DEFAULT);
+                    VERIFY(ret, FAIL, "H5Aopen_by_idx");
 
                     /* Create attributes, up to limit of compact form */
                     for(u = 0; u < max_compact; u++) {
@@ -5421,14 +5477,13 @@ test_attr_open_by_idx(hbool_t new_format, hid_t fcpl, hid_t fapl)
                     is_dense = H5O_is_attr_dense_test(my_dataset);
                     VERIFY(is_dense, FALSE, "H5O_is_attr_dense_test");
 
-                    /* Check for out of bound iteration */
-                    idx = u;
-                    ret = H5Aiterate2(my_dataset, ".", idx_type, order, &idx, attr_iterate2_cb, NULL, H5P_DEFAULT);
-                    VERIFY(ret, FAIL, "H5Aiterate2");
+                    /* Check for out of bound opening an attribute on an object */
+                    ret = H5Aopen_by_idx(my_dataset, ".", idx_type, order, (hsize_t)u, H5P_DEFAULT, H5P_DEFAULT);
+                    VERIFY(ret, FAIL, "H5Aopen_by_idx");
 
-                    /* Test iteration over attributes stored compactly */
-                    ret = attr_iterate_check(my_dataset, idx_type, order, u, &iter_info);
-                    CHECK(ret, FAIL, "attr_iterate_check");
+                    /* Test opening attributes by index stored compactly */
+                    ret = attr_open_by_idx_check(my_dataset, idx_type, order, u);
+                    CHECK(ret, FAIL, "attr_open_by_idx_check");
                 } /* end for */
 
 
@@ -5495,14 +5550,13 @@ test_attr_open_by_idx(hbool_t new_format, hid_t fcpl, hid_t fapl)
                         VERIFY(name_count, (max_compact * 2), "H5O_attr_dense_info_test");
                     } /* end if */
 
-                    /* Check for out of bound iteration */
-                    idx = u;
-                    ret = H5Aiterate2(my_dataset, ".", idx_type, order, &idx, attr_iterate2_cb, NULL, H5P_DEFAULT);
-                    VERIFY(ret, FAIL, "H5Aiterate2");
+                    /* Check for out of bound opening an attribute on an object */
+                    ret = H5Aopen_by_idx(my_dataset, ".", idx_type, order, (hsize_t)u, H5P_DEFAULT, H5P_DEFAULT);
+                    VERIFY(ret, FAIL, "H5Aopen_by_idx");
 
-                    /* Test iteration over attributes stored densely */
-                    ret = attr_iterate_check(my_dataset, idx_type, order, u, &iter_info);
-                    CHECK(ret, FAIL, "attr_iterate_check");
+                    /* Test opening attributes by index stored compactly */
+                    ret = attr_open_by_idx_check(my_dataset, idx_type, order, u);
+                    CHECK(ret, FAIL, "attr_open_by_idx_check");
                 } /* end for */
 
                 /* Close Datasets */
@@ -5529,6 +5583,286 @@ test_attr_open_by_idx(hbool_t new_format, hid_t fcpl, hid_t fapl)
     CHECK(ret, FAIL, "H5Sclose");
 }   /* test_attr_open_by_idx() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    attr_open_check
+ *
+ * Purpose:     Check opening attribute on an object
+ *
+ * Return:      Success:        0
+ *              Failure:        -1
+ *
+ * Programmer:  Quincey Koziol
+ *              Wednesday, February 21, 2007
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+attr_open_check(hid_t obj_id, unsigned max_attrs)
+{
+    hid_t       attr_id;        /* ID of attribute to test */
+    H5A_info_t  ainfo;          /* Attribute info */
+    char	attrname[NAME_BUF_SIZE];    /* Name of attribute */
+    int         old_nerrs;      /* Number of errors when entering this check */
+    unsigned    u;              /* Local index variable */
+    herr_t	ret;		/* Generic return value	*/
+
+    /* Retrieve the current # of reported errors */
+    old_nerrs = GetTestNumErrs();
+
+    /* Open each attribute on object by index and check that it's the correct one */
+    for(u = 0; u < max_attrs; u++) {
+        /* Open the attribute */
+        sprintf(attrname, "attr %02u", u);
+        attr_id = H5Aopen(obj_id, ".", attrname, H5P_DEFAULT, H5P_DEFAULT);
+        CHECK(attr_id, FAIL, "H5Aopen");
+
+        /* Get the attribute's information */
+        ret = H5Aget_info(attr_id, &ainfo);
+        CHECK(ret, FAIL, "H5Aget_info");
+
+        /* Check that the object is the correct one */
+        VERIFY(ainfo.corder, u, "H5Aget_info");
+
+        /* Close attribute */
+        ret = H5Aclose(attr_id);
+        CHECK(ret, FAIL, "H5Aclose");
+    } /* end for */
+
+    /* Retrieve current # of errors */
+    if(old_nerrs == GetTestNumErrs())
+        return(0);
+    else
+        return(-1);
+} /* end attr_open_check() */
+
+
+/****************************************************************
+**
+**  test_attr_open(): Test basic H5A (attribute) code.
+**      Tests opening attributes by name
+**
+****************************************************************/
+static void
+test_attr_open(hbool_t new_format, hid_t fcpl, hid_t fapl)
+{
+    hid_t	fid;		/* HDF5 File ID			*/
+    hid_t	dset1, dset2, dset3;	/* Dataset IDs			*/
+    hid_t	my_dataset;	/* Current dataset ID		*/
+    hid_t	sid;	        /* Dataspace ID			*/
+    hid_t	attr;	        /* Attribute ID			*/
+    hid_t	dcpl;	        /* Dataset creation property list ID */
+    unsigned    max_compact;    /* Maximum # of links to store in group compactly */
+    unsigned    min_dense;      /* Minimum # of links to store in group "densely" */
+    htri_t	is_empty;	/* Are there any attributes? */
+    htri_t	is_dense;	/* Are attributes stored densely? */
+    hsize_t     nattrs;         /* Number of attributes on object */
+    hsize_t     name_count;     /* # of records in name index */
+    hsize_t     corder_count;   /* # of records in creation order index */
+    hbool_t     use_index;      /* Use index on creation order values */
+    char	attrname[NAME_BUF_SIZE];    /* Name of attribute */
+    unsigned    curr_dset;      /* Current dataset to work on */
+    unsigned    u;              /* Local index variable */
+    herr_t	ret;		/* Generic return value		*/
+
+    /* Create dataspace for dataset & attributes */
+    sid = H5Screate(H5S_SCALAR);
+    CHECK(sid, FAIL, "H5Screate");
+
+    /* Create dataset creation property list */
+    dcpl = H5Pcreate(H5P_DATASET_CREATE);
+    CHECK(dcpl, FAIL, "H5Pcreate");
+
+    /* Query the attribute creation properties */
+    ret = H5Pget_attr_phase_change(dcpl, &max_compact, &min_dense);
+    CHECK(ret, FAIL, "H5Pget_attr_phase_change");
+
+    /* Loop over using index for creation order value */
+    for(use_index = FALSE; use_index <= TRUE; use_index++) {
+        /* Print appropriate test message */
+        if(use_index)
+            MESSAGE(5, ("Testing Opening Attributes By Name w/Creation Order Index\n"))
+        else
+            MESSAGE(5, ("Testing Opening Attributes By Name w/o Creation Order Index\n"))
+
+        /* Create file */
+        fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl);
+        CHECK(fid, FAIL, "H5Fcreate");
+
+        /* Set attribute creation order tracking & indexing for object */
+        ret = H5Pset_attr_creation_order(dcpl, (H5P_CRT_ORDER_TRACKED | (use_index ? H5P_CRT_ORDER_INDEXED : (unsigned)0)));
+        CHECK(ret, FAIL, "H5Pset_attr_creation_order");
+
+        /* Create datasets */
+        dset1 = H5Dcreate(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, dcpl);
+        CHECK(dset1, FAIL, "H5Dcreate");
+        dset2 = H5Dcreate(fid, DSET2_NAME, H5T_NATIVE_UCHAR, sid, dcpl);
+        CHECK(dset2, FAIL, "H5Dcreate");
+        dset3 = H5Dcreate(fid, DSET3_NAME, H5T_NATIVE_UCHAR, sid, dcpl);
+        CHECK(dset3, FAIL, "H5Dcreate");
+
+        /* Work on all the datasets */
+        for(curr_dset = 0; curr_dset < NUM_DSETS; curr_dset++) {
+            switch(curr_dset) {
+                case 0:
+                    my_dataset = dset1;
+                    break;
+
+                case 1:
+                    my_dataset = dset2;
+                    break;
+
+                case 2:
+                    my_dataset = dset3;
+                    break;
+
+                default:
+                    HDassert(0 && "Too many datasets!");
+            } /* end switch */
+
+            /* Check on dataset's attribute storage status */
+            is_empty = H5O_is_attr_empty_test(my_dataset);
+            VERIFY(is_empty, TRUE, "H5O_is_attr_empty_test");
+            is_dense = H5O_is_attr_dense_test(my_dataset);
+            VERIFY(is_dense, FALSE, "H5O_is_attr_dense_test");
+
+            /* Check for opening a non-existant attribute on an object with no attributes */
+            ret = H5Aopen(my_dataset, ".", "foo", H5P_DEFAULT, H5P_DEFAULT);
+            VERIFY(ret, FAIL, "H5Aopen");
+
+            /* Create attributes, up to limit of compact form */
+            for(u = 0; u < max_compact; u++) {
+                /* Create attribute */
+                sprintf(attrname, "attr %02u", u);
+                attr = H5Acreate(my_dataset, attrname, H5T_NATIVE_UINT, sid, H5P_DEFAULT);
+                CHECK(attr, FAIL, "H5Acreate");
+
+                /* Write data into the attribute */
+                ret = H5Awrite(attr, H5T_NATIVE_UINT, &u);
+                CHECK(ret, FAIL, "H5Awrite");
+
+                /* Close attribute */
+                ret = H5Aclose(attr);
+                CHECK(ret, FAIL, "H5Aclose");
+
+                /* Verify information for new attribute */
+                ret = attr_info_by_idx_check(my_dataset, attrname, (hsize_t)u, use_index);
+                CHECK(ret, FAIL, "attr_info_by_idx_check");
+            } /* end for */
+
+            /* Verify state of object */
+            ret = H5O_num_attrs_test(my_dataset, &nattrs);
+            CHECK(ret, FAIL, "H5O_num_attrs_test");
+            VERIFY(nattrs, max_compact, "H5O_num_attrs_test");
+            is_empty = H5O_is_attr_empty_test(my_dataset);
+            VERIFY(is_empty, FALSE, "H5O_is_attr_empty_test");
+            is_dense = H5O_is_attr_dense_test(my_dataset);
+            VERIFY(is_dense, FALSE, "H5O_is_attr_dense_test");
+
+            /* Check for opening a non-existant attribute on an object with compact attribute storage */
+            ret = H5Aopen(my_dataset, ".", "foo", H5P_DEFAULT, H5P_DEFAULT);
+            VERIFY(ret, FAIL, "H5Aopen");
+
+            /* Test opening attributes stored compactly */
+            ret = attr_open_check(my_dataset, u);
+            CHECK(ret, FAIL, "attr_open_check");
+        } /* end for */
+
+
+        /* Work on all the datasets */
+        for(curr_dset = 0; curr_dset < NUM_DSETS; curr_dset++) {
+            switch(curr_dset) {
+                case 0:
+                    my_dataset = dset1;
+                    break;
+
+                case 1:
+                    my_dataset = dset2;
+                    break;
+
+                case 2:
+                    my_dataset = dset3;
+                    break;
+
+                default:
+                    HDassert(0 && "Too many datasets!");
+            } /* end switch */
+
+            /* Create more attributes, to push into dense form */
+            for(u = max_compact; u < (max_compact * 2); u++) {
+                /* Create attribute */
+                sprintf(attrname, "attr %02u", u);
+                attr = H5Acreate(my_dataset, attrname, H5T_NATIVE_UINT, sid, H5P_DEFAULT);
+                CHECK(attr, FAIL, "H5Acreate");
+
+                /* Write data into the attribute */
+                ret = H5Awrite(attr, H5T_NATIVE_UINT, &u);
+                CHECK(ret, FAIL, "H5Awrite");
+
+                /* Close attribute */
+                ret = H5Aclose(attr);
+                CHECK(ret, FAIL, "H5Aclose");
+
+                /* Verify state of object */
+                if(u >= max_compact) {
+                    is_dense = H5O_is_attr_dense_test(my_dataset);
+                    VERIFY(is_dense, (new_format ? TRUE : FALSE), "H5O_is_attr_dense_test");
+                } /* end if */
+
+                /* Verify information for new attribute */
+                ret = attr_info_by_idx_check(my_dataset, attrname, (hsize_t)u, use_index);
+                CHECK(ret, FAIL, "attr_info_by_idx_check");
+            } /* end for */
+
+            /* Verify state of object */
+            ret = H5O_num_attrs_test(my_dataset, &nattrs);
+            CHECK(ret, FAIL, "H5O_num_attrs_test");
+            VERIFY(nattrs, (max_compact * 2), "H5O_num_attrs_test");
+            is_empty = H5O_is_attr_empty_test(my_dataset);
+            VERIFY(is_empty, FALSE, "H5O_is_attr_empty_test");
+            is_dense = H5O_is_attr_dense_test(my_dataset);
+            VERIFY(is_dense, (new_format ? TRUE : FALSE), "H5O_is_attr_dense_test");
+
+            if(new_format) {
+                /* Retrieve & verify # of records in the name & creation order indices */
+                ret = H5O_attr_dense_info_test(my_dataset, &name_count, &corder_count);
+                CHECK(ret, FAIL, "H5O_attr_dense_info_test");
+                if(use_index)
+                    VERIFY(name_count, corder_count, "H5O_attr_dense_info_test");
+                VERIFY(name_count, (max_compact * 2), "H5O_attr_dense_info_test");
+            } /* end if */
+
+            /* Check for opening a non-existant attribute on an object with dense attribute storage */
+            ret = H5Aopen(my_dataset, ".", "foo", H5P_DEFAULT, H5P_DEFAULT);
+            VERIFY(ret, FAIL, "H5Aopen");
+
+            /* Test opening attributes stored compactly */
+            ret = attr_open_check(my_dataset, u);
+            CHECK(ret, FAIL, "attr_open_check");
+        } /* end for */
+
+        /* Close Datasets */
+        ret = H5Dclose(dset1);
+        CHECK(ret, FAIL, "H5Dclose");
+        ret = H5Dclose(dset2);
+        CHECK(ret, FAIL, "H5Dclose");
+        ret = H5Dclose(dset3);
+        CHECK(ret, FAIL, "H5Dclose");
+
+        /* Close file */
+        ret = H5Fclose(fid);
+        CHECK(ret, FAIL, "H5Fclose");
+    } /* end for */
+
+    /* Close property list */
+    ret = H5Pclose(dcpl);
+    CHECK(ret, FAIL, "H5Pclose");
+
+    /* Close dataspace */
+    ret = H5Sclose(sid);
+    CHECK(ret, FAIL, "H5Sclose");
+}   /* test_attr_open() */
+
 /****************************************************************
 **
 **  test_attr_shared_write(): Test basic H5A (attribute) code.
@@ -5692,8 +6026,8 @@ test_attr_shared_write(hid_t fcpl, hid_t fapl)
             /* Alternate between creating "small" & "big" attributes */
             if(u % 2) {
                 /* Create "small" attribute on first dataset */
-                attr = H5Acreate(dataset, attrname, attr_tid, sid, H5P_DEFAULT);
-                CHECK(attr, FAIL, "H5Acreate");
+                attr = H5Acreate2(dataset, ".", attrname, attr_tid, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+                CHECK(attr, FAIL, "H5Acreate2");
 
                 /* Check that attribute is not shared */
                 is_shared = H5A_is_shared_test(attr);
@@ -5706,8 +6040,8 @@ test_attr_shared_write(hid_t fcpl, hid_t fapl)
             } /* end if */
             else {
                 /* Create "big" attribute on first dataset */
-                attr = H5Acreate(dataset, attrname, attr_tid, big_sid, H5P_DEFAULT);
-                CHECK(attr, FAIL, "H5Acreate");
+                attr = H5Acreate2(dataset, ".", attrname, attr_tid, big_sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+                CHECK(attr, FAIL, "H5Acreate2");
 
                 /* Check that attribute is shared */
                 is_shared = H5A_is_shared_test(attr);
@@ -5744,8 +6078,8 @@ test_attr_shared_write(hid_t fcpl, hid_t fapl)
             /* Alternate between creating "small" & "big" attributes */
             if(u % 2) {
                 /* Create "small" attribute on second dataset */
-                attr = H5Acreate(dataset2, attrname, attr_tid, sid, H5P_DEFAULT);
-                CHECK(attr, FAIL, "H5Acreate");
+                attr = H5Acreate2(dataset2, ".", attrname, attr_tid, sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+                CHECK(attr, FAIL, "H5Acreate2");
 
                 /* Check that attribute is not shared */
                 is_shared = H5A_is_shared_test(attr);
@@ -5758,8 +6092,8 @@ test_attr_shared_write(hid_t fcpl, hid_t fapl)
             } /* end if */
             else {
                 /* Create "big" attribute on second dataset */
-                attr = H5Acreate(dataset2, attrname, attr_tid, big_sid, H5P_DEFAULT);
-                CHECK(attr, FAIL, "H5Acreate");
+                attr = H5Acreate2(dataset2, ".", attrname, attr_tid, big_sid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+                CHECK(attr, FAIL, "H5Acreate2");
 
                 /* Check that attribute is shared */
                 is_shared = H5A_is_shared_test(attr);
@@ -7143,11 +7477,8 @@ test_attr(void)
                 test_attr_info_by_idx(new_format, my_fcpl, my_fapl);    /* Test querying attribute info by index */
                 test_attr_delete_by_idx(new_format, my_fcpl, my_fapl);  /* Test deleting attribute by index */
                 test_attr_iterate2(new_format, my_fcpl, my_fapl);       /* Test iterating over attributes by index */
-#ifdef NOT_YET
                 test_attr_open_by_idx(new_format, my_fcpl, my_fapl);    /* Test opening attributes by index */
-#else /* NOT_YET */
-HDfprintf(stderr, "Finish H5Aopen_by_idx() test!\n");
-#endif /* NOT_YET */
+                test_attr_open(new_format, my_fcpl, my_fapl);           /* Test opening attributes by name */
 
                 /* More complex tests with both "new format" and "shared" attributes */
                 if(use_shared == TRUE) {
@@ -7163,9 +7494,8 @@ HDfprintf(stderr, "Finish H5Aopen_by_idx() test!\n");
             test_attr_info_by_idx(new_format, fcpl, my_fapl);   /* Test querying attribute info by index */
             test_attr_delete_by_idx(new_format, fcpl, my_fapl); /* Test deleting attribute by index */
             test_attr_iterate2(new_format, fcpl, my_fapl);      /* Test iterating over attributes by index */
-#ifdef NOT_YET
             test_attr_open_by_idx(new_format, fcpl, my_fapl);   /* Test opening attributes by index */
-#endif /* NOT_YET */
+            test_attr_open(new_format, fcpl, my_fapl);          /* Test opening attributes by name */
         } /* end else */
     } /* end for */