[svn-r22233] Description:

    Correct several errors in fractal heap code: root indirect block was
getting pinned/protected more than once, "single" free space sections weren't
getting "re-parented" correctly when the heap transitioned between having a
root indirect block and a root direct block, and several related issues.  Also
cleaned up some warnings in library/tests.

Tested on:
    FreeBSD/32 8.2 (loyalty) w/gcc4.6, w/C++ & FORTRAN, in debug mode
    FreeBSD/64 8.2 (freedom) w/gcc4.6, w/C++ & FORTRAN, in debug mode
    Linux/32 2.6 (jam) w/PGI compilers, w/default API=1.8.x,
        w/C++ & FORTRAN, w/threadsafe, in debug mode
    Linux/64-amd64 2.6 (koala) w/Intel compilers, w/default API=1.6.x,
        w/C++ & FORTRAN, in production mode
    Mac OSX/64 10.7.3 (amazon) w/debug

12 files changed, 488 insertions, 161 deletions

diff --git a/src/H5FSprivate.h b/src/H5FSprivate.h
index ca7104c..f6a0034 100644
--- a/src/H5FSprivate.h
+++ b/src/H5FSprivate.h
@@ -155,7 +155,7 @@ typedef struct H5FS_stat_t {
 } H5FS_stat_t;
 
 /* Typedef for iteration operations */
-typedef herr_t (*H5FS_operator_t)(const H5FS_section_info_t *sect,
+typedef herr_t (*H5FS_operator_t)(H5FS_section_info_t *sect,
         void *operator_data/*in,out*/);
 
 
diff --git a/src/H5FSsection.c b/src/H5FSsection.c
index 914fa58..0f126c2 100644
--- a/src/H5FSsection.c
+++ b/src/H5FSsection.c
@@ -2244,7 +2244,7 @@ H5FS_sect_assert(const H5FS_t *fspace)
     hsize_t separate_obj;       /* The number of separate objects managed */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
-#ifndef QAK
+#ifdef QAK
 HDfprintf(stderr, "%s: fspace->tot_sect_count = %Hu\n", "H5FS_sect_assert", fspace->tot_sect_count);
 #endif /* QAK */
 
diff --git a/src/H5HF.c b/src/H5HF.c
index 9c911fd..a9750c9 100644
--- a/src/H5HF.c
+++ b/src/H5HF.c
@@ -156,9 +156,6 @@ H5HF_create(H5F_t *f, hid_t dxpl_id, const H5HF_create_t *cparam)
     H5HF_t *ret_value;          /* Return value */
 
     FUNC_ENTER_NOAPI(NULL)
-#ifdef QAK
-HDfprintf(stderr, "%s: Called\n", FUNC);
-#endif /* QAK */
 
     /*
      * Check arguments.
@@ -234,14 +231,8 @@ H5HF_open(H5F_t *f, hid_t dxpl_id, haddr_t fh_addr)
     HDassert(H5F_addr_defined(fh_addr));
 
     /* Load the heap header into memory */
-#ifdef QAK
-HDfprintf(stderr, "%s: fh_addr = %a\n", FUNC, fh_addr);
-#endif /* QAK */
     if(NULL == (hdr = H5HF_hdr_protect(f, dxpl_id, fh_addr, H5AC_READ)))
         HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, NULL, "unable to protect fractal heap header")
-#ifdef QAK
-HDfprintf(stderr, "%s: hdr->rc = %u, hdr->fspace = %p\n", FUNC, hdr->rc, hdr->fspace);
-#endif /* QAK */
 
     /* Check for pending heap deletion */
     if(hdr->pending_delete)
@@ -361,9 +352,6 @@ H5HF_insert(H5HF_t *fh, hid_t dxpl_id, size_t size, const void *obj,
     herr_t ret_value = SUCCEED;
 
     FUNC_ENTER_NOAPI(FAIL)
-#ifdef QAK
-HDfprintf(stderr, "%s: size = %Zu\n", FUNC, size);
-#endif /* QAK */
 
     /* Sanity check */
     HDassert(fh);
@@ -406,9 +394,6 @@ HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "'write once' managed blocks not su
     } /* end else */
 
 done:
-#ifdef QAK
-HDfprintf(stderr, "%s: Leaving, ret_value = %d\n", FUNC, ret_value);
-#endif /* QAK */
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5HF_insert() */
 
@@ -580,9 +565,6 @@ H5HF_write(H5HF_t *fh, hid_t dxpl_id, void *_id, hbool_t UNUSED *id_changed,
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
-#ifdef QAK
-HDfprintf(stderr, "%s: Called\n", FUNC);
-#endif /* QAK */
 
     /*
      * Check arguments.
@@ -720,9 +702,6 @@ H5HF_remove(H5HF_t *fh, hid_t dxpl_id, const void *_id)
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
-#ifdef QAK
-HDfprintf(stderr, "%s: Called\n", FUNC);
-#endif /* QAK */
 
     /*
      * Check arguments.
@@ -814,17 +793,9 @@ H5HF_close(H5HF_t *fh, hid_t dxpl_id)
          *      a reference loop and the objects couldn't be removed from
          *      the metadata cache - QAK)
          */
-#ifdef QAK
-HDfprintf(stderr, "%s; fh->hdr->man_iter_off = %Hu\n", FUNC, fh->hdr->man_iter_off);
-HDfprintf(stderr, "%s; fh->hdr->man_size = %Hu\n", FUNC, fh->hdr->man_size);
-HDfprintf(stderr, "%s; fh->hdr->rc = %Zu\n", FUNC, fh->hdr->rc);
-#endif /* QAK */
         if(H5HF_man_iter_ready(&fh->hdr->next_block))
             if(H5HF_man_iter_reset(&fh->hdr->next_block) < 0)
                 HGOTO_ERROR(H5E_HEAP, H5E_CANTRELEASE, FAIL, "can't reset block iterator")
-#ifdef QAK
-HDfprintf(stderr, "%s; After iterator reset fh->hdr->rc = %Zu\n", FUNC, fh->hdr->rc);
-#endif /* QAK */
 
         /* Shut down the huge object information */
         /* (Can't put this in header "destroy" routine, because it has
@@ -900,9 +871,6 @@ H5HF_delete(H5F_t *f, hid_t dxpl_id, haddr_t fh_addr)
     HDassert(H5F_addr_defined(fh_addr));
 
     /* Lock the heap header into memory */
-#ifdef QAK
-HDfprintf(stderr, "%s: fh_addr = %a\n", FUNC, fh_addr);
-#endif /* QAK */
     if(NULL == (hdr = H5HF_hdr_protect(f, dxpl_id, fh_addr, H5AC_WRITE)))
         HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect fractal heap header")
 
diff --git a/src/H5HFbtree2.c b/src/H5HFbtree2.c
index 023344c..34b74d7 100644
--- a/src/H5HFbtree2.c
+++ b/src/H5HFbtree2.c
@@ -352,7 +352,7 @@ HDfprintf(stderr, "%s: nrecord = {%a, %Hu, %Hu}\n", "H5HF_huge_bt2_indir_found",
 herr_t
 H5HF_huge_bt2_indir_remove(const void *nrecord, void *_udata)
 {
-    H5HF_huge_remove_ud1_t *udata = (H5HF_huge_remove_ud1_t *)_udata;   /* User callback data */
+    H5HF_huge_remove_ud_t *udata = (H5HF_huge_remove_ud_t *)_udata;   /* User callback data */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -570,7 +570,7 @@ HDfprintf(stderr, "%s: nrecord = {%a, %Hu, %x, %Hu, %Hu}\n", "H5HF_huge_bt2_filt
 herr_t
 H5HF_huge_bt2_filt_indir_remove(const void *nrecord, void *_udata)
 {
-    H5HF_huge_remove_ud1_t *udata = (H5HF_huge_remove_ud1_t *)_udata;   /* User callback data */
+    H5HF_huge_remove_ud_t *udata = (H5HF_huge_remove_ud_t *)_udata;   /* User callback data */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -759,7 +759,7 @@ H5HF_huge_bt2_filt_indir_debug(FILE *stream, const H5F_t UNUSED *f, hid_t UNUSED
 herr_t
 H5HF_huge_bt2_dir_remove(const void *nrecord, void *_udata)
 {
-    H5HF_huge_remove_ud1_t *udata = (H5HF_huge_remove_ud1_t *)_udata;   /* User callback data */
+    H5HF_huge_remove_ud_t *udata = (H5HF_huge_remove_ud_t *)_udata;   /* User callback data */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -984,7 +984,7 @@ HDfprintf(stderr, "%s: nrecord = {%a, %Hu, %x, %Hu}\n", "H5HF_huge_bt2_filt_dir_
 herr_t
 H5HF_huge_bt2_filt_dir_remove(const void *nrecord, void *_udata)
 {
-    H5HF_huge_remove_ud1_t *udata = (H5HF_huge_remove_ud1_t *)_udata;   /* User callback data */
+    H5HF_huge_remove_ud_t *udata = (H5HF_huge_remove_ud_t *)_udata;   /* User callback data */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
diff --git a/src/H5HFdbg.c b/src/H5HFdbg.c
index 4289c02..caaedc7 100644
--- a/src/H5HFdbg.c
+++ b/src/H5HFdbg.c
@@ -172,39 +172,31 @@ H5HF_dtable_debug(H5HF_dtable_t *dtable, FILE *stream, int indent, int fwidth)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5HF_hdr_debug
+ * Function:	H5HF_hdr_print
  *
- * Purpose:	Prints debugging info about a fractal heap header.
+ * Purpose:	Prints info about a fractal heap header.
  *
  * Return:	Non-negative on success/Negative on failure
  *
  * Programmer:	Quincey Koziol
- *		koziol@ncsa.uiuc.edu
- *		Feb 24 2006
+ *		koziol@hdfgroup.org
+ *		Feb 23 2012
  *
  *-------------------------------------------------------------------------
  */
-herr_t
-H5HF_hdr_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream, int indent, int fwidth)
+void
+H5HF_hdr_print(const H5HF_hdr_t *hdr, hid_t dxpl_id, hbool_t dump_internal, FILE *stream, int indent, int fwidth)
 {
-    H5HF_hdr_t	*hdr = NULL;             /* Fractal heap header info */
-    herr_t      ret_value = SUCCEED;    /* Return value */
-
-    FUNC_ENTER_NOAPI(FAIL)
+    FUNC_ENTER_NOAPI_NOINIT
 
     /*
      * Check arguments.
      */
-    HDassert(f);
-    HDassert(H5F_addr_defined(addr));
+    HDassert(hdr);
     HDassert(stream);
     HDassert(indent >= 0);
     HDassert(fwidth >= 0);
 
-    /* Load the fractal heap header */
-    if(NULL == (hdr = H5HF_hdr_protect(f, dxpl_id, addr, H5AC_READ)))
-	HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect fractal heap header")
-
     /* Print opening message */
     HDfprintf(stream, "%*sFractal Heap Header...\n", indent, "");
 
@@ -277,10 +269,66 @@ H5HF_hdr_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream, int indent,
                       "Filter mask for root direct block:",
                       hdr->pline_root_direct_filter_mask);
         } /* end if */
-        H5O_debug_id(H5O_PLINE_ID, f, dxpl_id, &(hdr->pline), stream,
+        H5O_debug_id(H5O_PLINE_ID, hdr->f, dxpl_id, &(hdr->pline), stream,
                              indent + 3, MAX(0, fwidth - 3));
     } /* end if */
 
+    /* Print internal (runtime) information, if requested */
+    if(dump_internal) {
+        HDfprintf(stream, "%*sFractal Heap Header Internal Information:\n", indent, "");
+
+        /* Dump root iblock, if there is one */
+        HDfprintf(stream, "%*s%-*s %x\n", indent + 3, "", MAX(0, fwidth - 3),
+                  "Root indirect block flags:",
+                  hdr->root_iblock_flags);
+        HDfprintf(stream, "%*s%-*s %p\n", indent + 3, "", MAX(0, fwidth - 3),
+                  "Root indirect block pointer:",
+                  hdr->root_iblock);
+        if(hdr->root_iblock)
+            H5HF_iblock_print(hdr->root_iblock, dump_internal, stream, indent + 3, fwidth);
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI_VOID
+} /* end H5HF_hdr_print() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_hdr_debug
+ *
+ * Purpose:	Prints debugging info about a fractal heap header.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Feb 24 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5HF_hdr_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream, int indent, int fwidth)
+{
+    H5HF_hdr_t	*hdr = NULL;             /* Fractal heap header info */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /*
+     * Check arguments.
+     */
+    HDassert(f);
+    HDassert(H5F_addr_defined(addr));
+    HDassert(stream);
+    HDassert(indent >= 0);
+    HDassert(fwidth >= 0);
+
+    /* Load the fractal heap header */
+    if(NULL == (hdr = H5HF_hdr_protect(f, dxpl_id, addr, H5AC_READ)))
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect fractal heap header")
+
+    /* Print the information about the heap's header */
+    H5HF_hdr_print(hdr, dxpl_id, FALSE, stream, indent, fwidth);
+
 done:
     if(hdr && H5AC_unprotect(f, dxpl_id, H5AC_FHEAP_HDR, addr, hdr, H5AC__NO_FLAGS_SET) < 0)
         HDONE_ERROR(H5E_HEAP, H5E_PROTECT, FAIL, "unable to release fractal heap header")
@@ -303,9 +351,9 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_dblock_debug_cb(const H5FS_section_info_t *_sect, void *_udata)
+H5HF_dblock_debug_cb(H5FS_section_info_t *_sect, void *_udata)
 {
-    const H5HF_free_section_t *sect = (const H5HF_free_section_t *)_sect;       /* Section to dump info */
+    H5HF_free_section_t *sect = (H5HF_free_section_t *)_sect;       /* Section to dump info */
     H5HF_debug_iter_ud1_t *udata = (H5HF_debug_iter_ud1_t *)_udata;         /* User data for callbacks */
     haddr_t sect_start, sect_end;       /* Section's beginning and ending offsets */
     haddr_t dblock_start, dblock_end;   /* Direct block's beginning and ending offsets */
@@ -501,51 +549,39 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5HF_iblock_debug
+ * Function:	H5HF_iblock_print
  *
  * Purpose:	Prints debugging info about a fractal heap indirect block.
  *
  * Return:	Non-negative on success/Negative on failure
  *
  * Programmer:	Quincey Koziol
- *		koziol@ncsa.uiuc.edu
- *		Mar  7 2006
+ *		koziol@hdfgroup.org
+ *		Feb 23 2012
  *
  *-------------------------------------------------------------------------
  */
-herr_t
-H5HF_iblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
-    int indent, int fwidth, haddr_t hdr_addr, unsigned nrows)
+void
+H5HF_iblock_print(const H5HF_indirect_t *iblock,
+    hbool_t dump_internal, FILE *stream, int indent, int fwidth)
 {
-    H5HF_hdr_t	*hdr = NULL;            /* Fractal heap header info */
-    H5HF_indirect_t *iblock = NULL;     /* Fractal heap direct block info */
-    hbool_t did_protect;                /* Whether we protected the indirect block or not */
+    const H5HF_hdr_t *hdr;              /* Pointer to heap's header */
     char temp_str[64];                  /* Temporary string, for formatting */
     size_t	u, v;                   /* Local index variable */
-    herr_t      ret_value = SUCCEED;    /* Return value */
 
-    FUNC_ENTER_NOAPI(FAIL)
+    FUNC_ENTER_NOAPI_NOINIT
 
     /*
      * Check arguments.
      */
-    HDassert(f);
-    HDassert(H5F_addr_defined(addr));
+    HDassert(iblock);
+    HDassert(iblock->hdr);
     HDassert(stream);
     HDassert(indent >= 0);
     HDassert(fwidth >= 0);
-    HDassert(H5F_addr_defined(hdr_addr));
-    HDassert(nrows > 0);
 
-    /* Load the fractal heap header */
-    if(NULL == (hdr = H5HF_hdr_protect(f, dxpl_id, hdr_addr, H5AC_READ)))
-	HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect fractal heap header")
-
-    /*
-     * Load the heap indirect block
-     */
-    if(NULL == (iblock = H5HF_man_iblock_protect(hdr, dxpl_id, addr, nrows, NULL, 0, FALSE, H5AC_READ, &did_protect)))
-	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, FAIL, "unable to load fractal heap indirect block")
+    /* Set up convenience variables */
+    hdr = iblock->hdr;
 
     /* Print opening message */
     HDfprintf(stream, "%*sFractal Heap Indirect Block...\n", indent, "");
@@ -623,6 +659,75 @@ H5HF_iblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
         HDfprintf(stream, "%*s%-*s\n", indent + 3, "", MAX(0, fwidth - 3),
                   "<none>");
 
+    /* Print internal (runtime) information, if requested */
+    if(dump_internal) {
+        HDfprintf(stream, "%*sFractal Indirect Block Internal Information:\n", indent, "");
+
+        /* Print general information */
+        HDfprintf(stream, "%*s%-*s %Zu\n", indent + 3, "", MAX(0, fwidth - 3),
+                  "Reference count:",
+                  iblock->rc);
+
+        /* Print parent's information */
+        HDfprintf(stream, "%*s%-*s %p\n", indent + 3, "", MAX(0, fwidth - 3),
+                  "Parent indirect block address:",
+                  iblock->parent);
+        if(iblock->parent)
+            H5HF_iblock_print(iblock->parent, TRUE, stream, indent + 6, fwidth);
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI_VOID
+} /* end H5HF_iblock_print() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_iblock_debug
+ *
+ * Purpose:	Prints debugging info about a fractal heap indirect block.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar  7 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5HF_iblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
+    int indent, int fwidth, haddr_t hdr_addr, unsigned nrows)
+{
+    H5HF_hdr_t	*hdr = NULL;            /* Fractal heap header info */
+    H5HF_indirect_t *iblock = NULL;     /* Fractal heap direct block info */
+    hbool_t did_protect;                /* Whether we protected the indirect block or not */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /*
+     * Check arguments.
+     */
+    HDassert(f);
+    HDassert(H5F_addr_defined(addr));
+    HDassert(stream);
+    HDassert(indent >= 0);
+    HDassert(fwidth >= 0);
+    HDassert(H5F_addr_defined(hdr_addr));
+    HDassert(nrows > 0);
+
+    /* Load the fractal heap header */
+    if(NULL == (hdr = H5HF_hdr_protect(f, dxpl_id, hdr_addr, H5AC_READ)))
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect fractal heap header")
+
+    /*
+     * Load the heap indirect block
+     */
+    if(NULL == (iblock = H5HF_man_iblock_protect(hdr, dxpl_id, addr, nrows, NULL, 0, FALSE, H5AC_READ, &did_protect)))
+	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, FAIL, "unable to load fractal heap indirect block")
+
+    /* Print the information about the heap's indirect block */
+    H5HF_iblock_print(iblock, FALSE, stream, indent, fwidth);
+
 done:
     if(iblock && H5HF_man_iblock_unprotect(iblock, dxpl_id, H5AC__NO_FLAGS_SET, did_protect) < 0)
         HDONE_ERROR(H5E_HEAP, H5E_PROTECT, FAIL, "unable to release fractal heap direct block")
@@ -647,9 +752,9 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_sects_debug_cb(const H5FS_section_info_t *_sect, void *_udata)
+H5HF_sects_debug_cb(H5FS_section_info_t *_sect, void *_udata)
 {
-    const H5HF_free_section_t *sect = (const H5HF_free_section_t *)_sect;       /* Section to dump info */
+    H5HF_free_section_t *sect = (H5HF_free_section_t *)_sect;       /* Section to dump info */
     H5HF_debug_iter_ud2_t *udata = (H5HF_debug_iter_ud2_t *)_udata;         /* User data for callbacks */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
diff --git a/src/H5HFhuge.c b/src/H5HFhuge.c
index 3bbd137..6f0b48e 100644
--- a/src/H5HFhuge.c
+++ b/src/H5HFhuge.c
@@ -899,7 +899,7 @@ done:
 herr_t
 H5HF_huge_remove(H5HF_hdr_t *hdr, hid_t dxpl_id, const uint8_t *id)
 {
-    H5HF_huge_remove_ud1_t udata;       /* User callback data for v2 B-tree remove call */
+    H5HF_huge_remove_ud_t udata;       /* User callback data for v2 B-tree remove call */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -1072,7 +1072,7 @@ done:
 herr_t
 H5HF_huge_delete(H5HF_hdr_t *hdr, hid_t dxpl_id)
 {
-    H5HF_huge_remove_ud1_t udata;       /* User callback data for v2 B-tree remove call */
+    H5HF_huge_remove_ud_t udata;       /* User callback data for v2 B-tree remove call */
     H5B2_remove_t op;                   /* Callback for v2 B-tree removal */
     herr_t ret_value = SUCCEED;         /* Return value */
 
diff --git a/src/H5HFiblock.c b/src/H5HFiblock.c
index 6c19b4f..342e228 100644
--- a/src/H5HFiblock.c
+++ b/src/H5HFiblock.c
@@ -140,8 +140,17 @@ H5HF_iblock_pin(H5HF_indirect_t *iblock)
     else {
         /* Check for pinning the root indirect block */
         if(iblock->block_off == 0) {
-            HDassert(iblock->hdr->root_iblock == NULL);
-            iblock->hdr->root_iblock = iblock;
+            /* Sanity check - shouldn't be recursively pinning root indirect block */
+            HDassert(0 == (iblock->hdr->root_iblock_flags & H5HF_ROOT_IBLOCK_PINNED));
+
+            /* Check if we should set the root iblock pointer */
+            if(0 == iblock->hdr->root_iblock_flags) {
+                HDassert(NULL == iblock->hdr->root_iblock);
+                iblock->hdr->root_iblock = iblock;
+            } /* end if */
+
+            /* Indicate that the root indirect block is pinned */
+            iblock->hdr->root_iblock_flags |= H5HF_ROOT_IBLOCK_PINNED;
         } /* end if */
     } /* end if */
 
@@ -192,12 +201,21 @@ H5HF_iblock_unpin(H5HF_indirect_t *iblock)
         par_iblock->child_iblocks[indir_idx] = NULL;
     } /* end if */
     else {
-        /* Check for unpinning the root indirect block */
+        /* Check for root indirect block */
         if(iblock->block_off == 0) {
-            HDassert(iblock->hdr->root_iblock);
-            iblock->hdr->root_iblock = NULL;
+            /* Sanity check - shouldn't be recursively unpinning root indirect block */
+            HDassert(iblock->hdr->root_iblock_flags & H5HF_ROOT_IBLOCK_PINNED);
+
+            /* Check if we should reset the root iblock pointer */
+            if(H5HF_ROOT_IBLOCK_PINNED == iblock->hdr->root_iblock_flags) {
+                HDassert(NULL != iblock->hdr->root_iblock);
+                iblock->hdr->root_iblock = NULL;
+            } /* end if */
+
+            /* Indicate that the root indirect block is unpinned */
+            iblock->hdr->root_iblock_flags &= ~(H5HF_ROOT_IBLOCK_PINNED);
         } /* end if */
-    } /* end if */
+    } /* end else */
 
     /* Mark block as evictable again */
     if(H5AC_unpin_entry(iblock) < 0)
@@ -273,18 +291,23 @@ H5HF_iblock_decr(H5HF_indirect_t *iblock)
 
     /* Mark block as evictable again when no child blocks depend on it */
     if(iblock->rc == 0) {
-        if(H5HF_iblock_unpin(iblock) < 0)
-            HGOTO_ERROR(H5E_HEAP, H5E_CANTUNPIN, FAIL, "unable to unpin fractal heap indirect block")
+        H5HF_hdr_t *hdr;			/* Fractal heap header */
+        haddr_t iblock_addr;		/* Address of fractal heap */
+        hbool_t expunge_iblock = FALSE;     /* Whether to expunge indirect block from heap */
+
+        /* Set up convenience variables */
+        hdr = iblock->hdr;
+        iblock_addr = iblock->addr;
 
         if(iblock->nchildren == 0) {
             /* Check for deleting root indirect block (and no root direct block) */
-            if(iblock->block_off == 0 && iblock->hdr->man_dtable.curr_root_rows > 0) {
+            if(iblock->block_off == 0 && hdr->man_dtable.curr_root_rows > 0) {
                 /* Reset root pointer information */
-                iblock->hdr->man_dtable.curr_root_rows = 0;
-                iblock->hdr->man_dtable.table_addr = HADDR_UNDEF;
+                hdr->man_dtable.curr_root_rows = 0;
+                hdr->man_dtable.table_addr = HADDR_UNDEF;
 
                 /* Reset header information back to "empty heap" state */
-                if(H5HF_hdr_empty(iblock->hdr) < 0)
+                if(H5HF_hdr_empty(hdr) < 0)
                     HGOTO_ERROR(H5E_HEAP, H5E_CANTSHRINK, FAIL, "can't make heap empty")
             } /* end if */
 
@@ -297,8 +320,18 @@ H5HF_iblock_decr(H5HF_indirect_t *iblock)
                 iblock->par_entry = 0;
             } /* end if */
 
+	    /* Mark indirect block for removal from the metadata cache */
+	    expunge_iblock = TRUE;
+        } /* end if */
+
+	/* Unpin the indirect block */
+        if(H5HF_iblock_unpin(iblock) < 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTUNPIN, FAIL, "unable to unpin fractal heap indirect block")
+
+	/* Check for expunging the indirect block from the metadata cache */
+	if(expunge_iblock) {
             /* Evict the indirect block from the metadata cache */
-            if(H5AC_expunge_entry(iblock->hdr->f, H5AC_dxpl_id, H5AC_FHEAP_IBLOCK, iblock->addr, H5AC__FREE_FILE_SPACE_FLAG) < 0)
+            if(H5AC_expunge_entry(hdr->f, H5AC_dxpl_id, H5AC_FHEAP_IBLOCK, iblock_addr, H5AC__FREE_FILE_SPACE_FLAG) < 0)
                 HGOTO_ERROR(H5E_HEAP, H5E_CANTREMOVE, FAIL, "unable to remove indirect block from cache")
         } /* end if */
     } /* end if */
@@ -420,6 +453,10 @@ H5HF_man_iblock_root_create(H5HF_hdr_t *hdr, hid_t dxpl_id, size_t min_dblock_si
             hdr->pline_root_direct_filter_mask = 0;
         } /* end if */
 
+        /* Scan free space sections to set any 'parent' pointers to new indirect block */
+        if(H5HF_space_create_root(hdr, dxpl_id, iblock) < 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTSET, FAIL, "can't set free space section info to new root indirect block")
+
         /* Unlock first (previously the root) direct block */
         if(H5AC_unprotect(hdr->f, dxpl_id, H5AC_FHEAP_DBLOCK, hdr->man_dtable.table_addr, dblock, H5AC__NO_FLAGS_SET) < 0)
             HGOTO_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap direct block")
@@ -859,6 +896,11 @@ H5HF_man_iblock_root_revert(H5HF_indirect_t *root_iblock, hid_t dxpl_id)
     if(H5HF_hdr_adjust_heap(hdr, (hsize_t)hdr->man_dtable.cparam.start_block_size, (hssize_t)hdr->man_dtable.row_tot_dblock_free[0]) < 0)
         HGOTO_ERROR(H5E_HEAP, H5E_CANTEXTEND, FAIL, "can't increase space to cover root direct block")
 
+    /* Scan free space sections to reset any 'parent' pointers */
+    if(H5HF_space_revert_root(hdr, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_HEAP, H5E_CANTRESET, FAIL, "can't reset free space section info")
+
+
 done:
     if(dblock && H5AC_unprotect(hdr->f, dxpl_id, H5AC_FHEAP_DBLOCK, dblock_addr, dblock, H5AC__NO_FLAGS_SET) < 0)
         HDONE_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap direct block")
@@ -1126,11 +1168,20 @@ H5HF_man_iblock_protect(H5HF_hdr_t *hdr, hid_t dxpl_id, haddr_t iblock_addr,
         else {
             /* Check for root indirect block */
             if(H5F_addr_eq(iblock_addr, hdr->man_dtable.table_addr)) {
-                /* Check for pointer to pinned indirect block in root */
-                if(hdr->root_iblock)
+                /* Check for valid pointer to pinned indirect block in root */
+                if(H5HF_ROOT_IBLOCK_PINNED == hdr->root_iblock_flags) {
+                    /* Sanity check */
+                    HDassert(NULL != hdr->root_iblock);
+
+                    /* Return the pointer to the pinned root indirect block */
                     iblock = hdr->root_iblock;
-                else
+                } /* end if */
+                else {
+                    /* Sanity check */
+                    HDassert(NULL == hdr->root_iblock);
+
                     should_protect = TRUE;
+                } /* end else */
             } /* end if */
             else
                 should_protect = TRUE;
@@ -1158,6 +1209,21 @@ H5HF_man_iblock_protect(H5HF_hdr_t *hdr, hid_t dxpl_id, haddr_t iblock_addr,
         /* Set the indirect block's address */
         iblock->addr = iblock_addr;
 
+        /* Check for root indirect block */
+        if(iblock->block_off == 0) {
+            /* Sanity check - shouldn't be recursively protecting root indirect block */
+            HDassert(0 == (hdr->root_iblock_flags & H5HF_ROOT_IBLOCK_PROTECTED));
+
+            /* Check if we should set the root iblock pointer */
+            if(0 == hdr->root_iblock_flags) {
+                HDassert(NULL == hdr->root_iblock);
+                hdr->root_iblock = iblock;
+            } /* end if */
+
+            /* Indicate that the root indirect block is protected */
+            hdr->root_iblock_flags |= H5HF_ROOT_IBLOCK_PROTECTED;
+        } /* end if */
+
         /* Indicate that the indirect block was protected */
         *did_protect = TRUE;
     } /* end if */
@@ -1202,6 +1268,21 @@ H5HF_man_iblock_unprotect(H5HF_indirect_t *iblock, hid_t dxpl_id,
     /* Check if we previously protected this indirect block */
     /* (as opposed to using an existing pointer to a pinned child indirect block) */
     if(did_protect) {
+        /* Check for root indirect block */
+        if(iblock->block_off == 0) {
+            /* Sanity check - shouldn't be recursively unprotecting root indirect block */
+            HDassert(iblock->hdr->root_iblock_flags & H5HF_ROOT_IBLOCK_PROTECTED);
+
+            /* Check if we should reset the root iblock pointer */
+            if(H5HF_ROOT_IBLOCK_PROTECTED == iblock->hdr->root_iblock_flags) {
+                HDassert(NULL != iblock->hdr->root_iblock);
+                iblock->hdr->root_iblock = NULL;
+            } /* end if */
+
+            /* Indicate that the root indirect block is unprotected */
+            iblock->hdr->root_iblock_flags &= ~(H5HF_ROOT_IBLOCK_PROTECTED);
+        } /* end if */
+
         /* Unprotect the indirect block */
         if(H5AC_unprotect(iblock->hdr->f, dxpl_id, H5AC_FHEAP_IBLOCK, iblock->addr, iblock, cache_flags) < 0)
             HGOTO_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap indirect block")
@@ -1215,7 +1296,7 @@ done:
 /*-------------------------------------------------------------------------
  * Function:	H5HF_man_iblock_attach
  *
- * Purpose:	Attach a block to an indirect block
+ * Purpose:	Attach a child block (direct or indirect) to an indirect block
  *
  * Return:	SUCCEED/FAIL
  *
@@ -1243,7 +1324,7 @@ H5HF_man_iblock_attach(H5HF_indirect_t *iblock, unsigned entry, haddr_t child_ad
     if(H5HF_iblock_incr(iblock) < 0)
         HGOTO_ERROR(H5E_HEAP, H5E_CANTINC, FAIL, "can't increment reference count on shared indirect block")
 
-    /* Point at the direct block */
+    /* Point at the child block */
     iblock->ents[entry].addr = child_addr;
 
     /* Check for I/O filters on this heap */
@@ -1280,7 +1361,7 @@ done:
 /*-------------------------------------------------------------------------
  * Function:	H5HF_man_iblock_detach
  *
- * Purpose:	Detach a block from an indirect block
+ * Purpose:	Detach a child block (direct or indirect) from an indirect block
  *
  * Return:	SUCCEED/FAIL
  *
@@ -1293,6 +1374,7 @@ done:
 herr_t
 H5HF_man_iblock_detach(H5HF_indirect_t *iblock, hid_t dxpl_id, unsigned entry)
 {
+    unsigned row;                       /* Row for entry */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -1306,16 +1388,14 @@ H5HF_man_iblock_detach(H5HF_indirect_t *iblock, hid_t dxpl_id, unsigned entry)
     /* Reset address of entry */
     iblock->ents[entry].addr = HADDR_UNDEF;
 
+    /* Compute row for entry */
+    row = entry / iblock->hdr->man_dtable.cparam.width;
+
     /* Check for I/O filters on this heap */
     if(iblock->hdr->filter_len > 0) {
-        unsigned row;           /* Row for entry */
-
         /* Sanity check */
         HDassert(iblock->filt_ents);
 
-        /* Compute row for entry */
-        row = entry / iblock->hdr->man_dtable.cparam.width;
-
         /* If this is a direct block, reset its initial size */
         if(row < iblock->hdr->man_dtable.max_direct_rows) {
             iblock->filt_ents[entry].size = 0;
@@ -1323,6 +1403,24 @@ H5HF_man_iblock_detach(H5HF_indirect_t *iblock, hid_t dxpl_id, unsigned entry)
         } /* end if */
     } /* end if */
 
+    /* Check for indirect block being detached */
+    if(row >= iblock->hdr->man_dtable.max_direct_rows) {
+        unsigned indir_idx;             /* Index in parent's child iblock pointer array */
+
+        /* Sanity check */
+        HDassert(iblock->child_iblocks);
+
+        /* Compute index in child iblock pointer array */
+        indir_idx = entry - (iblock->hdr->man_dtable.max_direct_rows
+                * iblock->hdr->man_dtable.cparam.width);
+
+        /* Sanity check */
+        HDassert(iblock->child_iblocks[indir_idx]);
+
+        /* Reset pointer to child indirect block in parent */
+        iblock->child_iblocks[indir_idx] = NULL;
+    } /* end if */
+
     /* Decrement the # of child blocks */
     /* (If the number of children drop to 0, the indirect block will be
      *  removed from the heap when its ref. count drops to zero and the
diff --git a/src/H5HFpkg.h b/src/H5HFpkg.h
index 2746302..498c45e 100644
--- a/src/H5HFpkg.h
+++ b/src/H5HFpkg.h
@@ -174,6 +174,11 @@
 #define H5HF_OP_MODIFY          0x0001          /* Operation will modify object */
 #define H5HF_OP_FLAGS           (H5HF_OP_MODIFY)        /* Bit-wise OR of all op flags */
 
+/* Flags for 'root_iblock_flags' field in header */
+#define H5HF_ROOT_IBLOCK_PINNED         0x01
+#define H5HF_ROOT_IBLOCK_PROTECTED      0x02
+
+
 /****************************/
 /* Package Private Typedefs */
 /****************************/
@@ -342,7 +347,8 @@ typedef struct H5HF_hdr_t {
     hbool_t     pending_delete; /* Heap is pending deletion */
     uint8_t     sizeof_size;    /* Size of file sizes */
     uint8_t     sizeof_addr;    /* Size of file addresses */
-    struct H5HF_indirect_t *root_iblock;    /* Pointer to pinned root indirect block */
+    struct H5HF_indirect_t *root_iblock;    /* Pointer to root indirect block */
+    unsigned    root_iblock_flags;      /* Flags to indicate whether root indirect block is pinned/protected */
     H5FS_t      *fspace;        /* Free space list for objects in heap */
     H5HF_block_iter_t next_block;   /* Block iterator for searching for next block with space */
     H5B2_t      *huge_bt2;      /* v2 B-tree handle for huge objects */
@@ -457,14 +463,14 @@ typedef struct H5HF_huge_bt2_filt_dir_rec_t {
 typedef struct {
     H5HF_hdr_t *hdr;            /* Fractal heap header */
     hid_t dxpl_id;              /* DXPL ID for operation */
-} H5HF_sect_add_ud1_t;
+} H5HF_sect_add_ud_t;
 
 /* User data for v2 B-tree 'remove' callback on 'huge' objects */
 typedef struct {
     H5HF_hdr_t *hdr;            /* Fractal heap header (in) */
     hid_t dxpl_id;              /* DXPL ID for operation (in) */
     hsize_t obj_len;            /* Length of object removed (out) */
-} H5HF_huge_remove_ud1_t;
+} H5HF_huge_remove_ud_t;
 
 /* User data for fractal heap header cache client callback */
 typedef struct H5HF_hdr_cache_ud_t {
@@ -701,10 +707,14 @@ H5_DLL herr_t H5HF_tiny_op(H5HF_hdr_t *hdr, const uint8_t *id,
 H5_DLL herr_t H5HF_tiny_remove(H5HF_hdr_t *fh, const uint8_t *id);
 
 /* Debugging routines for dumping file structures */
+H5_DLL void H5HF_hdr_print(const H5HF_hdr_t *hdr, hid_t dxpl_id,
+	hbool_t dump_internal, FILE *stream, int indent, int fwidth);
 H5_DLL herr_t H5HF_hdr_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr,
     FILE *stream, int indent, int fwidth);
 H5_DLL herr_t H5HF_dblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr,
     FILE *stream, int indent, int fwidth, haddr_t hdr_addr, size_t nrec);
+H5_DLL void H5HF_iblock_print(const H5HF_indirect_t *iblock, hbool_t dump_internal,
+    FILE *stream, int indent, int fwidth);
 H5_DLL herr_t H5HF_iblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr,
     FILE *stream, int indent, int fwidth, haddr_t hdr_addr, unsigned nrows);
 
@@ -733,6 +743,9 @@ H5_DLL herr_t H5HF_space_add(H5HF_hdr_t *hdr, hid_t dxpl_id,
     H5HF_free_section_t *node, unsigned flags);
 H5_DLL htri_t H5HF_space_find(H5HF_hdr_t *hdr, hid_t dxpl_id, hsize_t request,
     H5HF_free_section_t **node);
+H5_DLL herr_t H5HF_space_revert_root(const H5HF_hdr_t *hdr, hid_t dxpl_id);
+H5_DLL herr_t H5HF_space_create_root(const H5HF_hdr_t *hdr, hid_t dxpl_id,
+    H5HF_indirect_t *root_iblock);
 H5_DLL herr_t H5HF_space_size(H5HF_hdr_t *hdr, hid_t dxpl_id, hsize_t *fs_size);
 H5_DLL herr_t H5HF_space_remove(H5HF_hdr_t *hdr, hid_t dxpl_id,
     H5HF_free_section_t *node);
diff --git a/src/H5HFsection.c b/src/H5HFsection.c
index 38d9381..87fa069 100644
--- a/src/H5HFsection.c
+++ b/src/H5HFsection.c
@@ -665,42 +665,6 @@ H5HF_sect_single_dblock_info(H5HF_hdr_t *hdr, hid_t dxpl_id,
     HDassert(dblock_addr);
     HDassert(dblock_size);
 
-    /* Check for section in first direct block of heap */
-    if(sect->sect_info.addr < hdr->man_dtable.cparam.start_block_size) {
-        /* Check for heap changing from direct <-> indirect root (or vice versa)
-         *      while section was live.
-         */
-        if(sect->u.single.parent) {
-            /* Check for heap converting from indirect root to direct root while section was live */
-            if(hdr->man_dtable.curr_root_rows == 0) {
-                /* Release hold on parent indirect block */
-                if(H5HF_iblock_decr(sect->u.single.parent) < 0)
-                    HGOTO_ERROR(H5E_HEAP, H5E_CANTDEC, FAIL, "can't decrement reference count on section's indirect block")
-
-                /* Reset parent information */
-                sect->u.single.parent = NULL;
-                sect->u.single.par_entry = 0;
-            } /* end if */
-            else {
-                /* Check for heap converting from indirect to direct and back
-                 *      to indirect again, which would indicate a different
-                 *      indirect root block would be used for the parent of
-                 *      this section and the actual root indirect block.
-                 */
-                if(H5HF_sect_single_locate_parent(hdr, dxpl_id, TRUE, sect) < 0)
-                    HGOTO_ERROR(H5E_HEAP, H5E_CANTGET, FAIL, "can't get section's parent info")
-            } /* end else */
-        } /* end if */
-        else {
-            /* Check for heap converting from direct root to indirect root while section was live */
-            if(hdr->man_dtable.curr_root_rows != 0) {
-                /* Look up indirect block information for section */
-                if(H5HF_sect_single_locate_parent(hdr, dxpl_id, FALSE, sect) < 0)
-                    HGOTO_ERROR(H5E_HEAP, H5E_CANTGET, FAIL, "can't get section's parent info")
-            } /* end if */
-        } /* end else */
-    } /* end if */
-
     /* Check for root direct block */
     if(hdr->man_dtable.curr_root_rows == 0) {
         /* Retrieve direct block info from heap header */
@@ -860,7 +824,7 @@ H5HF_sect_single_add(H5FS_section_info_t *_sect, unsigned *flags, void *_udata)
      */
     if(!(*flags & H5FS_ADD_DESERIALIZING)) {
         H5HF_free_section_t *sect = (H5HF_free_section_t *)_sect;   /* Fractal heap free section */
-        H5HF_sect_add_ud1_t *udata = (H5HF_sect_add_ud1_t *)_udata;   /* User callback data */
+        H5HF_sect_add_ud_t *udata = (H5HF_sect_add_ud_t *)_udata;   /* User callback data */
         H5HF_hdr_t *hdr = udata->hdr;       /* Fractal heap header */
         hid_t dxpl_id = udata->dxpl_id;     /* DXPL ID for operation */
 
@@ -992,7 +956,7 @@ H5HF_sect_single_merge(H5FS_section_info_t *_sect1, H5FS_section_info_t *_sect2,
 {
     H5HF_free_section_t *sect1 = (H5HF_free_section_t *)_sect1;   /* Fractal heap free section */
     H5HF_free_section_t *sect2 = (H5HF_free_section_t *)_sect2;   /* Fractal heap free section */
-    H5HF_sect_add_ud1_t *udata = (H5HF_sect_add_ud1_t *)_udata;   /* User callback data */
+    H5HF_sect_add_ud_t *udata = (H5HF_sect_add_ud_t *)_udata;   /* User callback data */
     H5HF_hdr_t *hdr = udata->hdr;       /* Fractal heap header */
     hid_t dxpl_id = udata->dxpl_id;     /* DXPL ID for operation */
     herr_t ret_value = SUCCEED;         /* Return value */
@@ -1050,7 +1014,7 @@ static htri_t
 H5HF_sect_single_can_shrink(const H5FS_section_info_t *_sect, void *_udata)
 {
     const H5HF_free_section_t *sect = (const H5HF_free_section_t *)_sect;   /* Fractal heap free section */
-    H5HF_sect_add_ud1_t *udata = (H5HF_sect_add_ud1_t *)_udata;   /* User callback data */
+    H5HF_sect_add_ud_t *udata = (H5HF_sect_add_ud_t *)_udata;   /* User callback data */
     H5HF_hdr_t *hdr = udata->hdr;       /* Fractal heap header */
     htri_t ret_value = FALSE;           /* Return value */
 
@@ -1105,7 +1069,7 @@ static herr_t
 H5HF_sect_single_shrink(H5FS_section_info_t **_sect, void UNUSED *_udata)
 {
     H5HF_free_section_t **sect = (H5HF_free_section_t **)_sect;   /* Fractal heap free section */
-    H5HF_sect_add_ud1_t *udata = (H5HF_sect_add_ud1_t *)_udata;   /* User callback data */
+    H5HF_sect_add_ud_t *udata = (H5HF_sect_add_ud_t *)_udata;   /* User callback data */
     H5HF_hdr_t *hdr = udata->hdr;       /* Fractal heap header */
     hid_t dxpl_id = udata->dxpl_id;     /* DXPL ID for operation */
     H5HF_direct_t *dblock;              /* Pointer to direct block for section */
@@ -1814,7 +1778,7 @@ H5HF_sect_row_merge(H5FS_section_info_t *_sect1, H5FS_section_info_t *_sect2,
 {
     H5HF_free_section_t *sect1 = (H5HF_free_section_t *)_sect1;   /* Fractal heap free section */
     H5HF_free_section_t *sect2 = (H5HF_free_section_t *)_sect2;   /* Fractal heap free section */
-    H5HF_sect_add_ud1_t *udata = (H5HF_sect_add_ud1_t *)_udata;   /* User callback data */
+    H5HF_sect_add_ud_t *udata = (H5HF_sect_add_ud_t *)_udata;   /* User callback data */
     H5HF_hdr_t *hdr = udata->hdr;       /* Fractal heap header */
     hid_t dxpl_id = udata->dxpl_id;     /* DXPL ID for operation */
     herr_t ret_value = SUCCEED;         /* Return value */
@@ -1881,7 +1845,7 @@ static htri_t
 H5HF_sect_row_can_shrink(const H5FS_section_info_t *_sect, void UNUSED *_udata)
 {
     const H5HF_free_section_t *sect = (const H5HF_free_section_t *)_sect;   /* Fractal heap free section */
-    H5HF_sect_add_ud1_t *udata = (H5HF_sect_add_ud1_t *)_udata;   /* User callback data */
+    H5HF_sect_add_ud_t *udata = (H5HF_sect_add_ud_t *)_udata;   /* User callback data */
     H5HF_hdr_t *hdr = udata->hdr;       /* Fractal heap header */
     htri_t ret_value = FALSE;           /* Return value */
 
@@ -1919,7 +1883,7 @@ H5HF_sect_row_shrink(H5FS_section_info_t **_sect, void *_udata)
 {
     H5HF_free_section_t **sect = (H5HF_free_section_t **)_sect;   /* Fractal heap free section */
     H5HF_free_section_t *top_indir_sect; /* Top indirect section for row */
-    H5HF_sect_add_ud1_t *udata = (H5HF_sect_add_ud1_t *)_udata;   /* User callback data */
+    H5HF_sect_add_ud_t *udata = (H5HF_sect_add_ud_t *)_udata;   /* User callback data */
     H5HF_hdr_t *hdr = udata->hdr;       /* Fractal heap header */
     hid_t dxpl_id = udata->dxpl_id;     /* DXPL ID for operation */
     herr_t ret_value = SUCCEED;         /* Return value */
@@ -2161,7 +2125,7 @@ H5HF_sect_indirect_iblock_off(const H5HF_free_section_t *sect)
  *
  * Purpose:	Get the "top" indirect section
  *
- * Return:	Pointer to the top indirect sectin (can't fail)
+ * Return:	Pointer to the top indirect section (can't fail)
  *
  * Programmer:	Quincey Koziol
  *		koziol@ncsa.uiuc.edu
diff --git a/src/H5HFspace.c b/src/H5HFspace.c
index cec9b3a..01330d3 100644
--- a/src/H5HFspace.c
+++ b/src/H5HFspace.c
@@ -168,7 +168,7 @@ herr_t
 H5HF_space_add(H5HF_hdr_t *hdr, hid_t dxpl_id, H5HF_free_section_t *node,
     unsigned flags)
 {
-    H5HF_sect_add_ud1_t udata;          /* User data for free space manager 'add' */
+    H5HF_sect_add_ud_t udata;          /* User data for free space manager 'add' */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -246,6 +246,185 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5HF_space_revert_root_cb
+ *
+ * Purpose:	Callback routine from iterator, to reset 'parent' pointers in
+ *		sections, when the heap is changing from having a root indirect
+ *		block to a direct block.
+ *
+ * Return:	Success:	non-negative
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@hdfgroup.org
+ *		Feb 24 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5HF_space_revert_root_cb(H5FS_section_info_t *_sect, void UNUSED *_udata)
+{
+    H5HF_free_section_t *sect = (H5HF_free_section_t *)_sect;       /* Section to dump info */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /*
+     * Check arguments.
+     */
+    HDassert(sect);
+
+    /* Only modify "live" single blocks... */
+    if(sect->sect_info.type == H5HF_FSPACE_SECT_SINGLE && sect->sect_info.state == H5FS_SECT_LIVE) {
+        /* Release hold on previous indirect block (we must have one) */
+        HDassert(sect->u.single.parent);
+        if(H5HF_iblock_decr(sect->u.single.parent) < 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTDEC, FAIL, "can't decrement reference count on section's indirect block")
+
+        /* Reset parent information */
+        sect->u.single.parent = NULL;
+        sect->u.single.par_entry = 0;
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_space_revert_root_cb() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_space_revert_root
+ *
+ * Purpose:	Reset 'parent' pointers in sections, when the heap is
+ *		changing from having a root indirect block to a direct block.
+ *
+ * Return:	Success:	non-negative
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@hdfgroup.org
+ *		Feb 23 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5HF_space_revert_root(const H5HF_hdr_t *hdr, hid_t dxpl_id)
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /*
+     * Check arguments.
+     */
+    HDassert(hdr);
+
+    /* Only need to scan the sections if the free space has been initialized */
+    if(hdr->fspace) {
+	/* Iterate over all sections, reseting the parent pointers in 'single' sections */
+        if(H5FS_sect_iterate(hdr->f, dxpl_id, hdr->fspace, H5HF_space_revert_root_cb, NULL) < 0)
+            HGOTO_ERROR(H5E_FSPACE, H5E_BADITER, FAIL, "can't iterate over sections to reset parent pointers")
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_space_revert_root() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_space_create_root_cb
+ *
+ * Purpose:	Callback routine from iterator, to set 'parent' pointers in
+ *		sections to newly created root indirect block, when the heap
+ *		is changing from having a root direct block to an indirect block.
+ *
+ * Return:	Success:	non-negative
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@hdfgroup.org
+ *		Feb 24 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5HF_space_create_root_cb(H5FS_section_info_t *_sect, void *_udata)
+{
+    H5HF_free_section_t *sect = (H5HF_free_section_t *)_sect;       /* Section to dump info */
+    H5HF_indirect_t *root_iblock = (H5HF_indirect_t *)_udata;	/* User data for callback */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /*
+     * Check arguments.
+     */
+    HDassert(sect);
+    HDassert(root_iblock);
+
+    /* Sanity check sections */
+    /* (If we are switching from a direct block for the root block of the heap, */
+    /*	there should only be 'single' type sections. -QAK) */
+    HDassert(sect->sect_info.type == H5HF_FSPACE_SECT_SINGLE);
+
+    /* Increment ref. count on new root indirect block */
+    if(H5HF_iblock_incr(root_iblock) < 0)
+        HGOTO_ERROR(H5E_HEAP, H5E_CANTINC, FAIL, "can't increment reference count on section's indirect block")
+
+    /* Set parent info ("live" section must _NOT_ have a parent right now) */
+    if(sect->sect_info.state == H5FS_SECT_SERIALIZED)
+        sect->sect_info.state = H5FS_SECT_LIVE;         /* Mark "live" now */
+    else
+         HDassert(!sect->u.single.parent);
+    sect->u.single.parent = root_iblock;
+    sect->u.single.par_entry = 0;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_space_create_root_cb() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_space_create_root
+ *
+ * Purpose:	Set 'parent' pointers in sections to new indirect block, when
+ *		the heap is changing from having a root direct block to a
+ *		indirect block.
+ *
+ * Return:	Success:	non-negative
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@hdfgroup.org
+ *		Feb 24 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5HF_space_create_root(const H5HF_hdr_t *hdr, hid_t dxpl_id, H5HF_indirect_t *root_iblock)
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /*
+     * Check arguments.
+     */
+    HDassert(hdr);
+    HDassert(root_iblock);
+
+    /* Only need to scan the sections if the free space has been initialized */
+    if(hdr->fspace) {
+	/* Iterate over all sections, seting the parent pointers in 'single' sections to the new indirect block */
+        if(H5FS_sect_iterate(hdr->f, dxpl_id, hdr->fspace, H5HF_space_create_root_cb, root_iblock) < 0)
+            HGOTO_ERROR(H5E_FSPACE, H5E_BADITER, FAIL, "can't iterate over sections to set parent pointers")
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_space_create_root() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5HF_space_size
  *
  * Purpose:	Query the size of the heap's free space info on disk
diff --git a/src/H5MF.c b/src/H5MF.c
index fce151e..f9ca256 100644
--- a/src/H5MF.c
+++ b/src/H5MF.c
@@ -1172,9 +1172,9 @@ HDfprintf(stderr, "%s: Leaving\n", FUNC);
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5MF_sects_cb(const H5FS_section_info_t *_sect, void *_udata)
+H5MF_sects_cb(H5FS_section_info_t *_sect, void *_udata)
 {
-    const H5MF_free_section_t *sect = (const H5MF_free_section_t *)_sect;
+    H5MF_free_section_t *sect = (H5MF_free_section_t *)_sect;
     H5MF_sect_iter_ud_t *udata = (H5MF_sect_iter_ud_t *)_udata;
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
diff --git a/src/H5MFdbg.c b/src/H5MFdbg.c
index bdc811f..d6fc5ce 100644
--- a/src/H5MFdbg.c
+++ b/src/H5MFdbg.c
@@ -99,9 +99,9 @@ typedef struct {
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5MF_sects_debug_cb(const H5FS_section_info_t *_sect, void *_udata)
+H5MF_sects_debug_cb(H5FS_section_info_t *_sect, void *_udata)
 {
-    const H5MF_free_section_t *sect = (const H5MF_free_section_t *)_sect;       /* Section to dump info */
+    H5MF_free_section_t *sect = (H5MF_free_section_t *)_sect;       /* Section to dump info */
     H5MF_debug_iter_ud_t *udata = (H5MF_debug_iter_ud_t *)_udata;         /* User data for callbacks */
     herr_t      ret_value = SUCCEED;    /* Return value */