[svn-r13267] Description:

	Add more support for creation order index operations to attributes:
get deletions & compact<->dense storage transitions working.

Tested on:
	FreeBSD/32 6.2 (duty)
	Mac OS X/32 10.4.8 (amazon)

8 files changed, 404 insertions, 90 deletions

diff --git a/src/H5Adense.c b/src/H5Adense.c
index 460e82a..e56b0cb 100644
--- a/src/H5Adense.c
+++ b/src/H5Adense.c
@@ -722,6 +722,9 @@ H5A_dense_copy_fh_cb(const void *obj, size_t UNUSED obj_len, void *_udata)
     if(NULL == (udata->attr = (H5A_t *)H5O_msg_decode(udata->f, udata->dxpl_id, H5O_ATTR_ID, (const unsigned char *)obj)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTDECODE, FAIL, "can't decode attribute")
 
+    /* Set the creation order index for the attribute */
+    udata->attr->crt_idx = udata->record->corder;
+
     /* Check whether we should "reconstitute" the shared message info */
     if(udata->record->flags & H5O_MSG_FLAG_SHARED)
         H5SM_reconstitute(&(udata->attr->sh_loc), udata->record->id);
@@ -1082,31 +1085,43 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5A_dense_remove_bt2_cb(const void *_record, void *_bt2_udata)
+H5A_dense_remove_bt2_cb(const void *_record, void *_udata)
 {
     const H5A_dense_bt2_name_rec_t *record = (const H5A_dense_bt2_name_rec_t *)_record;
-    H5A_bt2_ud_common_t *bt2_udata = (H5A_bt2_ud_common_t *)_bt2_udata;         /* User data for callback */
+    H5A_bt2_ud_rm_t *udata = (H5A_bt2_ud_rm_t *)_udata;         /* User data for callback */
+    H5A_t *attr = *(H5A_t **)udata->common.found_op_data;  /* Pointer to attribute to remove */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT(H5A_dense_remove_bt2_cb)
 
-    /* Check for inserting shared attribute */
+    /* Check for removing shared attribute */
     if(record->flags & H5O_MSG_FLAG_SHARED) {
         /* Decrement the reference count on the shared attribute message */
-        if(H5SM_try_delete(bt2_udata->f, bt2_udata->dxpl_id, H5O_ATTR_ID, &((*(H5A_t **)bt2_udata->found_op_data)->sh_loc)) < 0)
+        if(H5SM_try_delete(udata->common.f, udata->common.dxpl_id, H5O_ATTR_ID, &(attr->sh_loc)) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "unable to delete shared attribute")
     } /* end if */
     else {
         /* Perform the deletion action on the attribute */
         /* (takes care of shared & committed datatype/dataspace components) */
-        if(H5O_attr_delete(bt2_udata->f, bt2_udata->dxpl_id, *(H5A_t **)bt2_udata->found_op_data) < 0)
+        if(H5O_attr_delete(udata->common.f, udata->common.dxpl_id, attr) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
         /* Remove record from fractal heap */
-        if(H5HF_remove(bt2_udata->fheap, bt2_udata->dxpl_id, &record->id) < 0)
+        if(H5HF_remove(udata->common.fheap, udata->common.dxpl_id, &record->id) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTREMOVE, FAIL, "unable to remove attribute from fractal heap")
     } /* end else */
 
+    /* Check for removing the link from the creation order index */
+    if(H5F_addr_defined(udata->corder_bt2_addr)) {
+        /* Set up the user data for the v2 B-tree 'record remove' callback */
+        udata->common.corder = attr->crt_idx;
+
+        /* Remove the record from the name index v2 B-tree */
+        if(H5B2_remove(udata->common.f, udata->common.dxpl_id, H5A_BT2_CORDER, udata->corder_bt2_addr,
+                udata, NULL, NULL) < 0)
+            HGOTO_ERROR(H5E_SYM, H5E_CANTREMOVE, FAIL, "unable to remove attribute from creation order index v2 B-tree")
+    } /* end if */
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5A_dense_remove_bt2_cb() */
@@ -1128,7 +1143,7 @@ done:
 herr_t
 H5A_dense_remove(H5F_t *f, hid_t dxpl_id, const H5O_t *oh, const char *name)
 {
-    H5A_bt2_ud_common_t udata;          /* User data for v2 B-tree record removal */
+    H5A_bt2_ud_rm_t udata;              /* User data for v2 B-tree record removal */
     H5HF_t *fheap = NULL;               /* Fractal heap handle */
     H5HF_t *shared_fheap = NULL;        /* Fractal heap handle for shared header messages */
     H5A_t *attr_copy = NULL;            /* Copy of attribute to remove */
@@ -1169,16 +1184,15 @@ H5A_dense_remove(H5F_t *f, hid_t dxpl_id, const H5O_t *oh, const char *name)
     } /* end if */
 
     /* Set up the user data for the v2 B-tree 'record remove' callback */
-    udata.f = f;
-    udata.dxpl_id = dxpl_id;
-    udata.fheap = fheap;
-    udata.shared_fheap = shared_fheap;
-    udata.name = name;
-    udata.name_hash = H5_checksum_lookup3(name, HDstrlen(name), 0);
-    udata.flags = 0;
-    udata.corder = 0;
-    udata.found_op = H5A_dense_fnd_cb;       /* v2 B-tree comparison callback */
-    udata.found_op_data = &attr_copy;
+    udata.common.f = f;
+    udata.common.dxpl_id = dxpl_id;
+    udata.common.fheap = fheap;
+    udata.common.shared_fheap = shared_fheap;
+    udata.common.name = name;
+    udata.common.name_hash = H5_checksum_lookup3(name, HDstrlen(name), 0);
+    udata.common.found_op = H5A_dense_fnd_cb;       /* v2 B-tree comparison callback */
+    udata.common.found_op_data = &attr_copy;
+    udata.corder_bt2_addr = oh->corder_bt2_addr;
 
     /* Remove the record from the name index v2 B-tree */
     if(H5B2_remove(f, dxpl_id, H5A_BT2_NAME, oh->name_bt2_addr, &udata, H5A_dense_remove_bt2_cb, &udata) < 0)
@@ -1302,37 +1316,38 @@ H5A_dense_delete_bt2_cb(const void *_record, void *_bt2_udata)
 {
     const H5A_dense_bt2_name_rec_t *record = (const H5A_dense_bt2_name_rec_t *)_record; /* Record from B-tree */
     H5A_bt2_ud_common_t *bt2_udata = (H5A_bt2_ud_common_t *)_bt2_udata;         /* User data for callback */
-    H5HF_t *fheap;                      /* Fractal heap handle for attribute storage */
-    H5A_fh_ud_cp_t fh_udata;            /* User data for fractal heap 'op' callback */
+    H5A_t *attr = NULL;                 /* Attribute being removed */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT(H5A_dense_delete_bt2_cb)
 
     /* Check for shared attribute */
-    if(record->flags & H5O_MSG_FLAG_SHARED)
-        fheap = bt2_udata->shared_fheap;
-    else
-        fheap = bt2_udata->fheap;
-
-    /* Prepare user data for callback */
-    /* down */
-    fh_udata.f = bt2_udata->f;
-    fh_udata.dxpl_id = bt2_udata->dxpl_id;
-    fh_udata.record = record;
-    /* up */
-    fh_udata.attr = NULL;
-
-    /* Call fractal heap 'op' routine, to copy the attribute information */
-    if(H5HF_op(fheap, bt2_udata->dxpl_id, &record->id, H5A_dense_copy_fh_cb, &fh_udata) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPERATE, FAIL, "heap op callback failed")
-
-    /* Check for shared attribute */
     if(record->flags & H5O_MSG_FLAG_SHARED) {
+        H5O_shared_t sh_mesg;   /* Temporary shared message info */
+
+        /* "reconstitute" the shared message info for the attribute */
+        H5SM_reconstitute(&sh_mesg, record->id);
+
         /* Decrement the reference count on the shared attribute message */
-        if(H5SM_try_delete(bt2_udata->f, bt2_udata->dxpl_id, H5O_ATTR_ID, &(fh_udata.attr->sh_loc)) < 0)
+        if(H5SM_try_delete(bt2_udata->f, bt2_udata->dxpl_id, H5O_ATTR_ID, &sh_mesg) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "unable to delete shared attribute")
     } /* end if */
     else {
+        H5A_fh_ud_cp_t fh_udata;            /* User data for fractal heap 'op' callback */
+
+        /* Prepare user data for callback */
+        /* down */
+        fh_udata.f = bt2_udata->f;
+        fh_udata.dxpl_id = bt2_udata->dxpl_id;
+        fh_udata.record = record;
+        /* up */
+        fh_udata.attr = NULL;
+
+        /* Call fractal heap 'op' routine, to copy the attribute information */
+        if(H5HF_op(bt2_udata->fheap, bt2_udata->dxpl_id, &record->id, H5A_dense_copy_fh_cb, &fh_udata) < 0)
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTOPERATE, FAIL, "heap op callback failed")
+        attr = fh_udata.attr;
+
         /* Perform the deletion action on the attribute */
         /* (takes care of shared/committed datatype & dataspace components) */
         if(H5O_attr_delete(bt2_udata->f, bt2_udata->dxpl_id, fh_udata.attr) < 0)
@@ -1341,8 +1356,8 @@ H5A_dense_delete_bt2_cb(const void *_record, void *_bt2_udata)
 
 done:
     /* Release resources */
-    if(fh_udata.attr)
-        H5O_msg_free_real(H5O_MSG_ATTR, fh_udata.attr);
+    if(attr)
+        H5O_msg_free_real(H5O_MSG_ATTR, attr);
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5A_dense_delete_bt2_cb() */
@@ -1366,8 +1381,6 @@ H5A_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_t *oh)
 {
     H5A_bt2_ud_common_t udata;          /* v2 B-tree user data for deleting attributes */
     H5HF_t *fheap = NULL;               /* Fractal heap handle */
-    H5HF_t *shared_fheap = NULL;        /* Fractal heap handle for shared header messages */
-    htri_t attr_sharable;               /* Flag indicating attributes are sharable */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI(H5A_dense_delete, FAIL)
@@ -1382,31 +1395,11 @@ H5A_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_t *oh)
     if(NULL == (fheap = H5HF_open(f, dxpl_id, oh->attr_fheap_addr)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open fractal heap")
 
-    /* Check if attributes are shared in this file */
-    if((attr_sharable = H5SM_type_shared(f, H5O_ATTR_ID, dxpl_id)) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "can't determine if attributes are shared")
-
-    /* Get handle for shared message heap, if attributes are sharable */
-    if(attr_sharable) {
-        haddr_t shared_fheap_addr;      /* Address of fractal heap to use */
-
-        /* Retrieve the address of the shared message's fractal heap */
-        if(H5SM_get_fheap_addr(f, dxpl_id, H5O_ATTR_ID, &shared_fheap_addr) < 0)
-            HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "can't get shared message heap address")
-
-        /* Check if there are any shared messages currently */
-        if(H5F_addr_defined(shared_fheap_addr)) {
-            /* Open the fractal heap for shared header messages */
-            if(NULL == (shared_fheap = H5HF_open(f, dxpl_id, shared_fheap_addr)))
-                HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open fractal heap")
-        } /* end if */
-    } /* end if */
-
     /* Create the "udata" information for v2 B-tree 'delete' */
     udata.f = f;
     udata.dxpl_id = dxpl_id;
     udata.fheap = fheap;
-    udata.shared_fheap = shared_fheap;
+    udata.shared_fheap = NULL;
     udata.name = NULL;
     udata.name_hash = 0;
     udata.flags = 0;
@@ -1420,15 +1413,18 @@ H5A_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_t *oh)
     oh->name_bt2_addr = HADDR_UNDEF;
 
     /* Release resources */
-    if(shared_fheap) {
-        if(H5HF_close(shared_fheap, dxpl_id) < 0)
-            HGOTO_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "can't close fractal heap")
-        shared_fheap = NULL;
-    } /* end if */
     if(H5HF_close(fheap, dxpl_id) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "can't close fractal heap")
     fheap = NULL;
 
+    /* Check if we should delete the creation order index v2 B-tree */
+    if(H5F_addr_defined(oh->corder_bt2_addr)) {
+        /* Delete the creation order index, without adjusting the ref. count on the attributes  */
+        if(H5B2_delete(f, dxpl_id, H5A_BT2_CORDER, oh->corder_bt2_addr, NULL, NULL) < 0)
+            HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to delete v2 B-tree for creation order index")
+        oh->corder_bt2_addr = HADDR_UNDEF;
+    } /* end if */
+
     /* Delete fractal heap */
     if(H5HF_delete(f, dxpl_id, oh->attr_fheap_addr) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete fractal heap")
@@ -1436,8 +1432,6 @@ H5A_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_t *oh)
 
 done:
     /* Release resources */
-    if(shared_fheap && H5HF_close(shared_fheap, dxpl_id) < 0)
-        HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "can't close fractal heap")
     if(fheap && H5HF_close(fheap, dxpl_id) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "can't close fractal heap")
 
diff --git a/src/H5Apkg.h b/src/H5Apkg.h
index 3fa7c75..708672a 100644
--- a/src/H5Apkg.h
+++ b/src/H5Apkg.h
@@ -124,6 +124,16 @@ typedef struct H5A_bt2_ud_ins_t {
     H5O_fheap_id_t id;                  /* Heap ID of attribute to insert    */
 } H5A_bt2_ud_ins_t;
 
+/*
+ * Data exchange structure for dense attribute storage.  This structure is
+ * passed through the v2 B-tree layer when removing attributes.
+ */
+typedef struct H5A_bt2_ud_rm_t {
+    /* downward */
+    H5A_bt2_ud_common_t common;         /* Common info for B-tree user data (must be first) */
+    haddr_t corder_bt2_addr;            /* v2 B-tree address of creation order index */
+} H5A_bt2_ud_rm_t;
+
 /* Data structure to hold table of attributes for an object */
 typedef struct {
     size_t      nattrs;         /* # of attributes in table */
diff --git a/src/H5Edefin.h b/src/H5Edefin.h
index 5638305..35579ea 100644
--- a/src/H5Edefin.h
+++ b/src/H5Edefin.h
@@ -1,5 +1,4 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
- * Copyright by The HDF Group.                                               *
  * Copyright by the Board of Trustees of the University of Illinois.         *
  * All rights reserved.                                                      *
  *                                                                           *
@@ -9,8 +8,8 @@
  * of the source code distribution tree; Copyright.html can be found at the  *
  * root level of an installed copy of the electronic HDF5 document set and   *
  * is linked from the top-level documents page.  It can also be found at     *
- * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
- * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /* Generated automatically by bin/make_err -- do not edit */
diff --git a/src/H5Einit.h b/src/H5Einit.h
index ac02d48..8b2429a 100644
--- a/src/H5Einit.h
+++ b/src/H5Einit.h
@@ -1,5 +1,4 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
- * Copyright by The HDF Group.                                               *
  * Copyright by the Board of Trustees of the University of Illinois.         *
  * All rights reserved.                                                      *
  *                                                                           *
@@ -9,8 +8,8 @@
  * of the source code distribution tree; Copyright.html can be found at the  *
  * root level of an installed copy of the electronic HDF5 document set and   *
  * is linked from the top-level documents page.  It can also be found at     *
- * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
- * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /* Generated automatically by bin/make_err -- do not edit */
diff --git a/src/H5Epubgen.h b/src/H5Epubgen.h
index 8386e0f..ccd1d52 100644
--- a/src/H5Epubgen.h
+++ b/src/H5Epubgen.h
@@ -1,5 +1,4 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
- * Copyright by The HDF Group.                                               *
  * Copyright by the Board of Trustees of the University of Illinois.         *
  * All rights reserved.                                                      *
  *                                                                           *
@@ -9,8 +8,8 @@
  * of the source code distribution tree; Copyright.html can be found at the  *
  * root level of an installed copy of the electronic HDF5 document set and   *
  * is linked from the top-level documents page.  It can also be found at     *
- * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
- * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /* Generated automatically by bin/make_err -- do not edit */
diff --git a/src/H5Eterm.h b/src/H5Eterm.h
index dedc313..1c4e762 100644
--- a/src/H5Eterm.h
+++ b/src/H5Eterm.h
@@ -1,5 +1,4 @@
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
- * Copyright by The HDF Group.                                               *
  * Copyright by the Board of Trustees of the University of Illinois.         *
  * All rights reserved.                                                      *
  *                                                                           *
@@ -9,8 +8,8 @@
  * of the source code distribution tree; Copyright.html can be found at the  *
  * root level of an installed copy of the electronic HDF5 document set and   *
  * is linked from the top-level documents page.  It can also be found at     *
- * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
- * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /* Generated automatically by bin/make_err -- do not edit */
diff --git a/src/H5Gdense.c b/src/H5Gdense.c
index 51a70d0..865c93f 100644
--- a/src/H5Gdense.c
+++ b/src/H5Gdense.c
@@ -120,7 +120,6 @@ typedef struct {
     /* downward */
     H5G_bt2_ud_common_t common;         /* Common info for B-tree user data (must be first) */
     hbool_t     rem_from_fheap;         /* Whether to remove the link from the fractal heap */
-    hbool_t     rem_from_corder_index;  /* Whether to remove the link from the creation order index */
     haddr_t     corder_bt2_addr;        /* Address of v2 B-tree indexing creation order */
     H5RS_str_t *grp_full_path_r;        /* Full path of group where link is removed */
     hbool_t     replace_names;          /* Whether to replace the names of open objects */
@@ -134,7 +133,6 @@ typedef struct {
     /* downward */
     H5F_t       *f;                     /* Pointer to file that fractal heap is in */
     hid_t       dxpl_id;                /* DXPL for operation                */
-    hbool_t     rem_from_corder_index;  /* Whether to remove the link from the creation order index */
     haddr_t     corder_bt2_addr;        /* Address of v2 B-tree indexing creation order */
     H5RS_str_t *grp_full_path_r;        /* Full path of group where link is removed */
     hbool_t     replace_names;          /* Whether to replace the names of open objects */
@@ -1347,7 +1345,7 @@ H5G_dense_remove_fh_cb(const void *obj, size_t UNUSED obj_len, void *_udata)
         HGOTO_ERROR(H5E_SYM, H5E_CANTDECODE, FAIL, "can't decode link")
 
     /* Check for removing the link from the creation order index */
-    if(udata->rem_from_corder_index) {
+    if(H5F_addr_defined(udata->corder_bt2_addr)) {
         H5G_bt2_ud_common_t bt2_udata;         /* Info for B-tree callbacks */
 
         /* Set up the user data for the v2 B-tree 'record remove' callback */
@@ -1355,7 +1353,6 @@ H5G_dense_remove_fh_cb(const void *obj, size_t UNUSED obj_len, void *_udata)
         bt2_udata.corder = lnk->corder;
 
         /* Remove the record from the name index v2 B-tree */
-        HDassert(H5F_addr_defined(udata->corder_bt2_addr));
         if(H5B2_remove(udata->f, udata->dxpl_id, H5G_BT2_CORDER, udata->corder_bt2_addr,
                 &bt2_udata, NULL, NULL) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTREMOVE, FAIL, "unable to remove link from creation order index v2 B-tree")
@@ -1406,7 +1403,6 @@ H5G_dense_remove_bt2_cb(const void *_record, void *_bt2_udata)
     /* Set up the user data for fractal heap 'op' callback */
     fh_udata.f = bt2_udata->common.f;
     fh_udata.dxpl_id = bt2_udata->common.dxpl_id;
-    fh_udata.rem_from_corder_index = bt2_udata->rem_from_corder_index;
     fh_udata.corder_bt2_addr = bt2_udata->corder_bt2_addr;
     fh_udata.grp_full_path_r = bt2_udata->grp_full_path_r;
     fh_udata.replace_names = bt2_udata->replace_names;
@@ -1469,7 +1465,6 @@ H5G_dense_remove(H5F_t *f, hid_t dxpl_id, const H5O_linfo_t *linfo,
     udata.common.found_op = NULL;
     udata.common.found_op_data = NULL;
     udata.rem_from_fheap = TRUE;
-    udata.rem_from_corder_index = H5F_addr_defined(linfo->corder_bt2_addr);
     udata.corder_bt2_addr = linfo->corder_bt2_addr;
     udata.grp_full_path_r = grp_full_path_r;
     udata.replace_names = TRUE;
@@ -1569,7 +1564,7 @@ H5G_dense_remove_by_idx_bt2_cb(const void *_record, void *_bt2_udata)
         HGOTO_ERROR(H5E_SYM, H5E_CANTOPERATE, FAIL, "link removal callback failed")
     HDassert(fh_udata.lnk);
 
-    /* Check for removing the link from the creation order index */
+    /* Check for removing the link from the "other" index (creation order, when name used and vice versa) */
     if(H5F_addr_defined(bt2_udata->other_bt2_addr)) {
         H5G_bt2_ud_common_t other_bt2_udata;    /* Info for B-tree callbacks */
         const H5B2_class_t *other_bt2_class;    /* Class of "other" v2 B-tree */
@@ -1778,7 +1773,7 @@ H5G_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_linfo_t *linfo, hbool_t adj_link)
         udata.common.found_op = NULL;
         udata.common.found_op_data = NULL;
         udata.rem_from_fheap = FALSE;           /* handled in "bulk" below by deleting entire heap */
-        udata.rem_from_corder_index = FALSE;
+        udata.corder_bt2_addr = linfo->corder_bt2_addr;
         udata.grp_full_path_r = NULL;
         udata.replace_names = FALSE;
 
@@ -1803,7 +1798,10 @@ H5G_dense_delete(H5F_t *f, hid_t dxpl_id, H5O_linfo_t *linfo, hbool_t adj_link)
         HDassert(H5F_addr_defined(linfo->corder_bt2_addr));
         if(H5B2_delete(f, dxpl_id, H5G_BT2_CORDER, linfo->corder_bt2_addr, NULL, NULL) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_CANTDELETE, FAIL, "unable to delete v2 B-tree for creation order index")
+        linfo->corder_bt2_addr = HADDR_UNDEF;
     } /* end if */
+    else
+        HDassert(!H5F_addr_defined(linfo->corder_bt2_addr));
 
     /* Delete the fractal heap */
     if(H5HF_delete(f, dxpl_id, linfo->link_fheap_addr) < 0)
diff --git a/test/tattr.c b/test/tattr.c
index 8c71e40..1e2807b 100644
--- a/test/tattr.c
+++ b/test/tattr.c
@@ -3056,6 +3056,321 @@ test_attr_corder_create_dense(hid_t fcpl, hid_t fapl)
 
 /****************************************************************
 **
+**  test_attr_corder_transition(): Test basic H5A (attribute) code.
+**      Tests attribute storage transitions on objects with attribute creation order info
+**
+****************************************************************/
+static void
+test_attr_corder_transition(hid_t fcpl, hid_t fapl)
+{
+    hid_t	fid;		/* HDF5 File ID			*/
+    hid_t	dataset;	/* 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 */
+    char	attrname[NAME_BUF_SIZE];        /* Name of attribute */
+    unsigned    u;              /* Local index variable */
+    herr_t	ret;		/* Generic return value		*/
+
+    /* Output message about test being performed */
+    MESSAGE(5, ("Testing Storage Transitions of Attributes with Creation Order Info\n"));
+
+    /* Create file */
+    fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, fcpl, fapl);
+    CHECK(fid, FAIL, "H5Fcreate");
+
+    /* Create dataset creation property list */
+    dcpl = H5Pcreate(H5P_DATASET_CREATE);
+    CHECK(dcpl, FAIL, "H5Pcreate");
+
+    /* Set attribute creation order tracking & indexing for object */
+    ret = H5Pset_attr_creation_order(dcpl, (H5P_CRT_ORDER_TRACKED | H5P_CRT_ORDER_INDEXED));
+    CHECK(ret, FAIL, "H5Pset_attr_creation_order");
+
+    /* Create dataspace for dataset & attributes */
+    sid = H5Screate(H5S_SCALAR);
+    CHECK(sid, FAIL, "H5Screate");
+
+    /* Create a dataset */
+    dataset = H5Dcreate(fid, DSET1_NAME, H5T_NATIVE_UCHAR, sid, dcpl);
+    CHECK(dataset, FAIL, "H5Dcreate");
+
+    /* Check on dataset's attribute storage status */
+    is_empty = H5O_is_attr_empty_test(dataset);
+    VERIFY(is_empty, TRUE, "H5O_is_attr_empty_test");
+    is_dense = H5O_is_attr_dense_test(dataset);
+    VERIFY(is_dense, FALSE, "H5O_is_attr_dense_test");
+
+    /* Query the attribute creation properties */
+    ret = H5Pget_attr_phase_change(dcpl, &max_compact, &min_dense);
+    CHECK(ret, FAIL, "H5Pget_attr_phase_change");
+
+    /* Close Dataset */
+    ret = H5Dclose(dataset);
+    CHECK(ret, FAIL, "H5Dclose");
+
+    /* Close property list */
+    ret = H5Pclose(dcpl);
+    CHECK(ret, FAIL, "H5Pclose");
+
+    /* Close file */
+    ret = H5Fclose(fid);
+    CHECK(ret, FAIL, "H5Fclose");
+
+
+    /* Re-open file */
+    fid = H5Fopen(FILENAME, H5F_ACC_RDWR, fapl);
+    CHECK(fid, FAIL, "H5Fopen");
+
+    /* Open dataset created */
+    dataset = H5Dopen(fid, DSET1_NAME);
+    CHECK(dataset, FAIL, "H5Dopen");
+
+    /* Create several attributes, but keep storage in compact form */
+    for(u = 0; u < max_compact; u++) {
+        /* Create attribute */
+        sprintf(attrname, "attr %02u", u);
+        attr = H5Acreate(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 */
+        ret = H5O_num_attrs_test(dataset, &nattrs);
+        CHECK(ret, FAIL, "H5O_num_attrs_test");
+        VERIFY(nattrs, (u + 1), "H5O_num_attrs_test");
+        is_empty = H5O_is_attr_empty_test(dataset);
+        VERIFY(is_empty, FALSE, "H5O_is_attr_empty_test");
+        is_dense = H5O_is_attr_dense_test(dataset);
+        VERIFY(is_dense, FALSE, "H5O_is_attr_dense_test");
+    } /* end for */
+
+    /* Create another attribute, to push into dense storage */
+    sprintf(attrname, "attr %02u", max_compact);
+    attr = H5Acreate(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 */
+    ret = H5O_num_attrs_test(dataset, &nattrs);
+    CHECK(ret, FAIL, "H5O_num_attrs_test");
+    VERIFY(nattrs, (max_compact + 1), "H5O_num_attrs_test");
+    is_empty = H5O_is_attr_empty_test(dataset);
+    VERIFY(is_empty, FALSE, "H5O_is_attr_empty_test");
+    is_dense = H5O_is_attr_dense_test(dataset);
+    VERIFY(is_dense, TRUE, "H5O_is_attr_dense_test");
+
+    /* Retrieve & verify # of records in the name & creation order indices */
+    ret = H5O_attr_dense_info_test(dataset, &name_count, &corder_count);
+    CHECK(ret, FAIL, "H5O_attr_dense_info_test");
+    VERIFY(name_count, corder_count, "H5O_attr_dense_info_test");
+
+    /* Delete several attributes from object, until attribute storage resumes compact form */
+    for(u = max_compact; u >= min_dense; u--) {
+        sprintf(attrname, "attr %02u", u);
+        ret = H5Adelete(dataset, attrname);
+        CHECK(ret, FAIL, "H5Adelete");
+
+        /* Verify state of object */
+        ret = H5O_num_attrs_test(dataset, &nattrs);
+        CHECK(ret, FAIL, "H5O_num_attrs_test");
+        VERIFY(nattrs, u, "H5O_num_attrs_test");
+        is_empty = H5O_is_attr_empty_test(dataset);
+        VERIFY(is_empty, FALSE, "H5O_is_attr_empty_test");
+        is_dense = H5O_is_attr_dense_test(dataset);
+        VERIFY(is_dense, TRUE, "H5O_is_attr_dense_test");
+
+        /* Retrieve & verify # of records in the name & creation order indices */
+        ret = H5O_attr_dense_info_test(dataset, &name_count, &corder_count);
+        CHECK(ret, FAIL, "H5O_attr_dense_info_test");
+        VERIFY(name_count, corder_count, "H5O_attr_dense_info_test");
+    } /* end for */
+
+    /* Delete another attribute, to push attribute storage into compact form */
+    sprintf(attrname, "attr %02u", (min_dense - 1));
+    ret = H5Adelete(dataset, attrname);
+    CHECK(ret, FAIL, "H5Adelete");
+
+    /* Verify state of object */
+    ret = H5O_num_attrs_test(dataset, &nattrs);
+    CHECK(ret, FAIL, "H5O_num_attrs_test");
+    VERIFY(nattrs, (min_dense - 1), "H5O_num_attrs_test");
+    is_empty = H5O_is_attr_empty_test(dataset);
+    VERIFY(is_empty, FALSE, "H5O_is_attr_empty_test");
+    is_dense = H5O_is_attr_dense_test(dataset);
+    VERIFY(is_dense, FALSE, "H5O_is_attr_dense_test");
+
+    /* Re-add attributes to get back into dense form */
+    for(u = (min_dense - 1); u < (max_compact + 1); u++) {
+        /* Create attribute */
+        sprintf(attrname, "attr %02u", u);
+        attr = H5Acreate(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");
+    } /* end for */
+
+    /* Verify state of object */
+    ret = H5O_num_attrs_test(dataset, &nattrs);
+    CHECK(ret, FAIL, "H5O_num_attrs_test");
+    VERIFY(nattrs, (max_compact + 1), "H5O_num_attrs_test");
+    is_empty = H5O_is_attr_empty_test(dataset);
+    VERIFY(is_empty, FALSE, "H5O_is_attr_empty_test");
+    is_dense = H5O_is_attr_dense_test(dataset);
+    VERIFY(is_dense, TRUE, "H5O_is_attr_dense_test");
+
+    /* Retrieve & verify # of records in the name & creation order indices */
+    ret = H5O_attr_dense_info_test(dataset, &name_count, &corder_count);
+    CHECK(ret, FAIL, "H5O_attr_dense_info_test");
+    VERIFY(name_count, corder_count, "H5O_attr_dense_info_test");
+
+    /* Close Dataset */
+    ret = H5Dclose(dataset);
+    CHECK(ret, FAIL, "H5Dclose");
+
+    /* Close file */
+    ret = H5Fclose(fid);
+    CHECK(ret, FAIL, "H5Fclose");
+
+
+    /* Re-open file */
+    fid = H5Fopen(FILENAME, H5F_ACC_RDWR, fapl);
+    CHECK(fid, FAIL, "H5Fopen");
+
+    /* Open dataset created */
+    dataset = H5Dopen(fid, DSET1_NAME);
+    CHECK(dataset, FAIL, "H5Dopen");
+
+    /* Check on dataset's attribute storage status */
+    ret = H5O_num_attrs_test(dataset, &nattrs);
+    CHECK(ret, FAIL, "H5O_num_attrs_test");
+    VERIFY(nattrs, (max_compact + 1), "H5O_num_attrs_test");
+    is_empty = H5O_is_attr_empty_test(dataset);
+    VERIFY(is_empty, FALSE, "H5O_is_attr_empty_test");
+    is_dense = H5O_is_attr_dense_test(dataset);
+    VERIFY(is_dense, TRUE, "H5O_is_attr_dense_test");
+
+    /* Retrieve & verify # of records in the name & creation order indices */
+    ret = H5O_attr_dense_info_test(dataset, &name_count, &corder_count);
+    CHECK(ret, FAIL, "H5O_attr_dense_info_test");
+    VERIFY(name_count, corder_count, "H5O_attr_dense_info_test");
+
+    /* Delete several attributes from object, until attribute storage resumes compact form */
+    for(u = max_compact; u >= min_dense; u--) {
+        sprintf(attrname, "attr %02u", u);
+        ret = H5Adelete(dataset, attrname);
+        CHECK(ret, FAIL, "H5Adelete");
+
+        /* Verify state of object */
+        ret = H5O_num_attrs_test(dataset, &nattrs);
+        CHECK(ret, FAIL, "H5O_num_attrs_test");
+        VERIFY(nattrs, u, "H5O_num_attrs_test");
+        is_empty = H5O_is_attr_empty_test(dataset);
+        VERIFY(is_empty, FALSE, "H5O_is_attr_empty_test");
+        is_dense = H5O_is_attr_dense_test(dataset);
+        VERIFY(is_dense, TRUE, "H5O_is_attr_dense_test");
+
+        /* Retrieve & verify # of records in the name & creation order indices */
+        ret = H5O_attr_dense_info_test(dataset, &name_count, &corder_count);
+        CHECK(ret, FAIL, "H5O_attr_dense_info_test");
+        VERIFY(name_count, corder_count, "H5O_attr_dense_info_test");
+    } /* end for */
+
+    /* Delete another attribute, to push attribute storage into compact form */
+    sprintf(attrname, "attr %02u", (min_dense - 1));
+    ret = H5Adelete(dataset, attrname);
+    CHECK(ret, FAIL, "H5Adelete");
+
+    /* Verify state of object */
+    ret = H5O_num_attrs_test(dataset, &nattrs);
+    CHECK(ret, FAIL, "H5O_num_attrs_test");
+    VERIFY(nattrs, (min_dense - 1), "H5O_num_attrs_test");
+    is_empty = H5O_is_attr_empty_test(dataset);
+    VERIFY(is_empty, FALSE, "H5O_is_attr_empty_test");
+    is_dense = H5O_is_attr_dense_test(dataset);
+    VERIFY(is_dense, FALSE, "H5O_is_attr_dense_test");
+
+    /* Re-add attributes to get back into dense form */
+    for(u = (min_dense - 1); u < (max_compact + 1); u++) {
+        /* Create attribute */
+        sprintf(attrname, "attr %02u", u);
+        attr = H5Acreate(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");
+    } /* end for */
+
+    /* Verify state of object */
+    ret = H5O_num_attrs_test(dataset, &nattrs);
+    CHECK(ret, FAIL, "H5O_num_attrs_test");
+    VERIFY(nattrs, (max_compact + 1), "H5O_num_attrs_test");
+    is_empty = H5O_is_attr_empty_test(dataset);
+    VERIFY(is_empty, FALSE, "H5O_is_attr_empty_test");
+    is_dense = H5O_is_attr_dense_test(dataset);
+    VERIFY(is_dense, TRUE, "H5O_is_attr_dense_test");
+
+    /* Retrieve & verify # of records in the name & creation order indices */
+    ret = H5O_attr_dense_info_test(dataset, &name_count, &corder_count);
+    CHECK(ret, FAIL, "H5O_attr_dense_info_test");
+    VERIFY(name_count, corder_count, "H5O_attr_dense_info_test");
+
+    /* Delete all attributes */
+    for(u = max_compact; u > 0; u--) {
+        sprintf(attrname, "attr %02u", u);
+        ret = H5Adelete(dataset, attrname);
+        CHECK(ret, FAIL, "H5Adelete");
+    } /* end for */
+    sprintf(attrname, "attr %02u", 0);
+    ret = H5Adelete(dataset, attrname);
+    CHECK(ret, FAIL, "H5Adelete");
+
+    /* Close Dataset */
+    ret = H5Dclose(dataset);
+    CHECK(ret, FAIL, "H5Dclose");
+
+    /* Close dataspace */
+    ret = H5Sclose(sid);
+    CHECK(ret, FAIL, "H5Sclose");
+
+    /* Close file */
+    ret = H5Fclose(fid);
+    CHECK(ret, FAIL, "H5Fclose");
+}   /* test_attr_corder_transition() */
+
+/****************************************************************
+**
 **  test_attr_shared_write(): Test basic H5A (attribute) code.
 **      Tests writing mix of shared & un-shared attributes in "compact" & "dense" storage
 **
@@ -4657,6 +4972,7 @@ test_attr(void)
         test_attr_corder_create_basic(my_fcpl, fapl2);  /* Test creating an object w/attribute creation order info */
         test_attr_corder_create_compact(my_fcpl, fapl2);  /* Test compact attribute storage on an object w/attribute creation order info */
         test_attr_corder_create_dense(my_fcpl, fapl2);  /* Test dense attribute storage on an object w/attribute creation order info */
+        test_attr_corder_transition(my_fcpl, fapl2);    /* Test attribute storage transitions on an object w/attribute creation order info */
     } /* end for */
 
     /* More complex tests with both "new format" and "shared" attributes */