[svn-r23656] Issue 8380 H5Zunregister caused seg fault: I added some protection measures:

  1. If any opened object uses the filter, let it fail.
  2. Flush all opened files to push any cached data to files.

Tested with h5committest.

14 files changed, 595 insertions, 28 deletions

diff --git a/MANIFEST b/MANIFEST
index 8fd716a..944072a 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -1091,6 +1091,7 @@
 ./test/tvlstr.c
 ./test/tvltypes.c
 ./test/unlink.c
+./test/unregister.c
 ./test/vfd.c
 ./test/test_filters_le.h5
 ./test/test_filters_be.h5
diff --git a/src/H5D.c b/src/H5D.c
index d204712..d81d4c7 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -572,19 +572,56 @@ done:
 hid_t
 H5Dget_create_plist(hid_t dset_id)
 {
-    H5D_t		*dset;                  /* Dataset structure */
+    H5D_t		*dataset;                  /* Dataset structure */
     H5P_genplist_t      *dcpl_plist;            /* Dataset's DCPL */
     H5P_genplist_t      *new_plist;             /* Copy of dataset's DCPL */
     H5O_fill_t          copied_fill;            /* Fill value to tweak */
     hid_t		new_dcpl_id = FAIL;
-    hid_t		ret_value;              /* Return value */
+    hid_t		ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("i", "i", dset_id);
 
     /* Check args */
-    if(NULL == (dset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
+    if(NULL == (dataset = (H5D_t *)H5I_object_verify(dset_id, H5I_DATASET)))
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset")
+
+    if((ret_value = H5D_get_create_plist(dataset)) < 0)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Dget_create_plist() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D_get_create_plist
+ *
+ * Purpose:	Private function for H5Dget_create_plist
+ *
+ * Return:	Success:	ID for a copy of the dataset creation
+ *				property list.  The template should be
+ *				released by calling H5P_close().
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *		Tuesday, February  3, 1998
+ *
+ *-------------------------------------------------------------------------
+ */
+hid_t
+H5D_get_create_plist(H5D_t *dset)
+{
+    H5P_genplist_t      *dcpl_plist;            /* Dataset's DCPL */
+    H5P_genplist_t      *new_plist;             /* Copy of dataset's DCPL */
+    H5O_fill_t          copied_fill;            /* Fill value to tweak */
+    hid_t		new_dcpl_id = FAIL;
+    hid_t		ret_value;              /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Check args */
     if(NULL == (dcpl_plist = (H5P_genplist_t *)H5I_object(dset->shared->dcpl_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
 
@@ -670,8 +707,8 @@ done:
             if(H5I_dec_app_ref(new_dcpl_id) < 0)
                 HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, FAIL, "unable to close temporary object")
 
-    FUNC_LEAVE_API(ret_value)
-} /* end H5Dget_create_plist() */
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D_get_create_plist() */
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Dprivate.h b/src/H5Dprivate.h
index 1e2b91d..7adc231 100644
--- a/src/H5Dprivate.h
+++ b/src/H5Dprivate.h
@@ -162,6 +162,7 @@ H5_DLL H5O_loc_t *H5D_oloc(H5D_t *dataset);
 H5_DLL H5G_name_t *H5D_nameof(H5D_t *dataset);
 H5_DLL H5T_t *H5D_typeof(const H5D_t *dset);
 H5_DLL herr_t H5D_flush(const H5F_t *f, hid_t dxpl_id);
+H5_DLL hid_t H5D_get_create_plist(H5D_t *dset);
 
 /* Functions that operate on vlen data */
 H5_DLL herr_t H5D_vlen_reclaim(hid_t type_id, H5S_t *space, hid_t plist_id,
diff --git a/src/H5G.c b/src/H5G.c
index a0e7767..bd4ad9b 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -499,7 +499,7 @@ H5Gget_create_plist(hid_t group_id)
     htri_t	        ginfo_exists;
     htri_t	        linfo_exists;
     htri_t              pline_exists;
-    H5G_t		*grp = NULL;
+    H5G_t		*group = NULL;
     H5P_genplist_t      *gcpl_plist;
     H5P_genplist_t      *new_plist;
     hid_t		new_gcpl_id = FAIL;
@@ -509,9 +509,47 @@ H5Gget_create_plist(hid_t group_id)
     H5TRACE1("i", "i", group_id);
 
     /* Check args */
-    if(NULL == (grp = (H5G_t *)H5I_object_verify(group_id, H5I_GROUP)))
+    if(NULL == (group = (H5G_t *)H5I_object_verify(group_id, H5I_GROUP)))
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group")
 
+    if((ret_value = H5G_get_create_plist(group)) < 0)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Gget_create_plist() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5G_get_create_plist
+ *
+ * Purpose:	Private function for H5Gget_create_plist
+ *
+ * Return:	Success:	ID for a copy of the group creation
+ *				property list.  The property list ID should be
+ *				released by calling H5Pclose().
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Quincey Koziol
+ *		Tuesday, October 25, 2005
+ *
+ *-------------------------------------------------------------------------
+ */
+hid_t
+H5G_get_create_plist(H5G_t *grp)
+{
+    H5O_linfo_t         linfo;		        /* Link info message            */
+    htri_t	        ginfo_exists;
+    htri_t	        linfo_exists;
+    htri_t              pline_exists;
+    H5P_genplist_t      *gcpl_plist;
+    H5P_genplist_t      *new_plist;
+    hid_t		new_gcpl_id = FAIL;
+    hid_t		ret_value = FAIL;
+
+    FUNC_ENTER_NOAPI(FAIL)
+
     /* Copy the default group creation property list */
     if(NULL == (gcpl_plist = (H5P_genplist_t *)H5I_object(H5P_LST_GROUP_CREATE_g)))
          HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get default group creation property list")
@@ -573,8 +611,8 @@ done:
                 HDONE_ERROR(H5E_SYM, H5E_CANTDEC, FAIL, "can't free")
     } /* end if */
 
-    FUNC_LEAVE_API(ret_value)
-} /* end H5Gget_create_plist() */
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5G_get_create_plist() */
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Gprivate.h b/src/H5Gprivate.h
index f765b52..50f8bda 100644
--- a/src/H5Gprivate.h
+++ b/src/H5Gprivate.h
@@ -243,6 +243,7 @@ H5_DLL herr_t H5G_obj_remove_by_idx(const struct H5O_loc_t *grp_oloc, H5RS_str_t
     H5_index_t idx_type, H5_iter_order_t order, hsize_t n, hid_t dxpl_id);
 H5_DLL herr_t H5G_obj_lookup_by_idx(const struct H5O_loc_t *grp_oloc, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, struct H5O_link_t *lnk, hid_t dxpl_id);
+H5_DLL hid_t H5G_get_create_plist(H5G_t *grp);
 
 /*
  * These functions operate on symbol table nodes.
diff --git a/src/H5I.c b/src/H5I.c
index 581356e..6a8c269 100644
--- a/src/H5I.c
+++ b/src/H5I.c
@@ -2002,21 +2002,55 @@ H5Isearch(H5I_type_t type, H5I_search_func_t func, void *key)
     if(H5I_IS_LIB_TYPE(type))
         HGOTO_ERROR(H5E_ATOM, H5E_BADGROUP, NULL, "cannot call public function on library type")
 
+    if((ret_value = H5I_search(type, func, key)) == NULL)
+        HGOTO_ERROR(H5E_ATOM, H5E_BADGROUP, NULL, "cannot call public function on library type")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Isearch() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5I_search
+ *
+ * Purpose:	Private function for H5Isearch
+ *
+ * Return:	Success:	The first object in the type for which FUNC
+ *				returns non-zero. NULL if FUNC returned zero
+ *				for every object in the type.
+ *
+ *		Failure:	NULL
+ *
+ * Programmer:	James Laird
+ *		Nathaniel Furrer
+ *		Friday, April 23, 2004
+ *
+ *-------------------------------------------------------------------------
+ */
+void *
+H5I_search(H5I_type_t _type, H5I_search_func_t _func, void *_key)
+{
+    H5I_search_ud_t udata;      /* Context for iteration */
+    void *ret_value;            /* Return value */
+
+    FUNC_ENTER_NOAPI(NULL)
+
     /* Set up udata struct */
-    udata.app_cb = func;
-    udata.app_key = key;
+    udata.app_cb = _func;
+    udata.app_key = _key;
     udata.ret_obj = NULL;
 
     /* Note that H5I_iterate returns an error code.  We ignore it 
      * here, as we can't do anything with it without revising the API.
      */
-    H5I_iterate(type, H5I_search_cb, &udata, TRUE);
+    if(H5I_iterate(_type, H5I_search_cb, &udata, TRUE) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_BADGROUP, NULL, "cannot call public function on library type")
 
     /* Set return value */
     ret_value = udata.ret_obj;
 
 done:
-    FUNC_LEAVE_API(ret_value)
+    FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5Isearch() */
 
 
diff --git a/src/H5Iprivate.h b/src/H5Iprivate.h
index ff1463d..28b6327 100644
--- a/src/H5Iprivate.h
+++ b/src/H5Iprivate.h
@@ -78,6 +78,7 @@ H5_DLL H5I_type_t H5I_get_type(hid_t id);
 H5_DLL hid_t H5I_get_file_id(hid_t obj_id, hbool_t app_ref);
 H5_DLL void *H5I_remove(hid_t id);
 H5_DLL void *H5I_remove_verify(hid_t id, H5I_type_t id_type);
+H5_DLL void *H5I_search(H5I_type_t _type, H5I_search_func_t _func, void *_key);
 H5_DLL herr_t H5I_iterate(H5I_type_t type, H5I_search_func_t func, void *udata, hbool_t app_ref);
 H5_DLL int H5I_get_ref(hid_t id, hbool_t app_ref);
 H5_DLL int H5I_inc_ref(hid_t id, hbool_t app_ref);
diff --git a/src/H5Pocpl.c b/src/H5Pocpl.c
index 880b46a..f80e4e7 100644
--- a/src/H5Pocpl.c
+++ b/src/H5Pocpl.c
@@ -1177,6 +1177,43 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5P_filter_in_pline
+ *
+ * Purpose:	Check whether the filter is in the pipeline of the object
+ *              creation property list.  
+ *
+ * Return:	TRUE:		found
+ *		FALSE:		not found
+ *              FAIL: 		error
+ *
+ * Programmer:	Raymond Lu
+ *              26 April 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5P_filter_in_pline(H5P_genplist_t *plist, H5Z_filter_t id)
+{
+    H5O_pline_t         pline;  /* Filter pipeline */
+    H5Z_filter_info_t *filter;  /* Pointer to filter information */
+    htri_t ret_value = SUCCEED;   /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Get pipeline info */
+    if(H5P_get(plist, H5O_CRT_PIPELINE_NAME, &pline) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get pipeline")
+
+    /* Check if the file is in the pipeline */
+    if((ret_value = H5Z_filter_in_pline(&pline, id)) < 0)
+        HGOTO_ERROR(H5E_PLINE, H5E_CANTCOMPARE, FAIL, "can't find filter")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5P_get_filter_by_id() */
+
+
+/*-------------------------------------------------------------------------
  * Function: H5Premove_filter
  *
  * Purpose: Deletes a filter from the dataset creation property list;
diff --git a/src/H5Pprivate.h b/src/H5Pprivate.h
index 6560064..083619b 100644
--- a/src/H5Pprivate.h
+++ b/src/H5Pprivate.h
@@ -108,6 +108,7 @@ H5_DLL herr_t H5P_modify_filter(H5P_genplist_t *plist, H5Z_filter_t filter,
 H5_DLL herr_t H5P_get_filter_by_id(H5P_genplist_t *plist, H5Z_filter_t id,
     unsigned int *flags, size_t *cd_nelmts, unsigned cd_values[],
     size_t namelen, char name[], unsigned *filter_config);
+H5_DLL htri_t H5P_filter_in_pline(H5P_genplist_t *plist, H5Z_filter_t id);
 
 /* *SPECIAL* Don't make more of these! -QAK */
 H5_DLL htri_t H5P_isa_class(hid_t plist_id, hid_t pclass_id);
diff --git a/src/H5Z.c b/src/H5Z.c
index 9f8b59d..5d68c25 100644
--- a/src/H5Z.c
+++ b/src/H5Z.c
@@ -22,6 +22,7 @@
 #include "H5private.h"		/* Generic Functions			*/
 #include "H5Dprivate.h"		/* Dataset functions			*/
 #include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5Fprivate.h"		/* File		  			*/
 #include "H5Iprivate.h"		/* IDs			  		*/
 #include "H5MMprivate.h"	/* Memory management			*/
 #include "H5Oprivate.h"		/* Object headers		  	*/
@@ -51,6 +52,9 @@ typedef enum {
     H5Z_PRELUDE_SET_LOCAL       /* Call "set local" callback */
 } H5Z_prelude_type_t;
 
+/* Maximal number of the list of opened objects (2^16) */
+#define NUM_OBJS        65536
+
 /* Local variables */
 static size_t		H5Z_table_alloc_g = 0;
 static size_t		H5Z_table_used_g = 0;
@@ -403,33 +407,133 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Z_unregister (H5Z_filter_t id)
+H5Z_unregister (H5Z_filter_t filter_id)
 {
-    size_t i;                   /* Local index variable */
+    hid_t  *file_list = NULL;
+    hid_t  *obj_id_list = NULL;
+    size_t num_obj_id = 0;
+    size_t num_file_id = 0;
+    H5F_t    *f = NULL;         /* File to query */
+    H5I_type_t id_type;
+    hid_t ocpl_id;
+    H5P_genplist_t  *plist;                 /* Property list */
+    size_t filter_index;                   /* Local index variable for filter */
+    int    i;
+    htri_t filter_in_pline = FALSE;
     herr_t ret_value=SUCCEED;   /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
-    assert (id>=0 && id<=H5Z_FILTER_MAX);
+    assert (filter_id>=0 && filter_id<=H5Z_FILTER_MAX);
 
     /* Is the filter already registered? */
-    for (i=0; i<H5Z_table_used_g; i++)
-	if (H5Z_table_g[i].id==id)
+    for (filter_index=0; filter_index<H5Z_table_used_g; filter_index++)
+	if (H5Z_table_g[filter_index].id==filter_id)
             break;
 
     /* Fail if filter not found */
-    if (i>=H5Z_table_used_g)
+    if (filter_index>=H5Z_table_used_g)
         HGOTO_ERROR(H5E_PLINE, H5E_NOTFOUND, FAIL, "filter is not registered")
 
+    /* Count the number of opened datasets and groups among all opened files */
+    if(H5F_get_obj_count(NULL, H5F_OBJ_DATASET | H5F_OBJ_GROUP, FALSE, &num_obj_id) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get object number")
+
+    if(num_obj_id) {
+        if(NULL == (obj_id_list = (hid_t *)H5MM_malloc(num_obj_id*sizeof(hid_t))))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "failed to allocate space")
+
+        /* Find all opened objects that may use the filter (datasets and groups).  Passing NULL as a pointer to 
+         * file structure indicates searching among all opened files */
+        if(H5F_get_obj_ids(NULL, H5F_OBJ_DATASET | H5F_OBJ_GROUP, num_obj_id, obj_id_list, FALSE, &num_obj_id) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get object IDs")
+    }
+
+    /* Check if any opened object (dataset or group) uses the filter.  If so, fail with a message */
+    for(i=0; i<num_obj_id; i++) {
+        if((id_type = H5I_get_type(obj_id_list[i])) < 0)
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "bad object id");
+
+        switch(id_type) {
+            case H5I_GROUP:
+            {
+                H5G_t *group = NULL;
+
+                if(NULL == (group = (H5G_t *)H5I_object_verify(obj_id_list[i], H5I_GROUP)))
+	            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a group")
+
+                if((ocpl_id = H5G_get_create_plist(group)) < 0) 
+                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get group creation property list")
+
+            }
+                break;
+
+            case H5I_DATASET:
+            {
+                H5D_t *dataset = NULL;
+
+                if(NULL == (dataset = (H5D_t *)H5I_object_verify(obj_id_list[i], H5I_DATASET)))
+	            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset")
+
+                if((ocpl_id = H5D_get_create_plist(dataset)) < 0) 
+                    HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get dataset creation property list")
+            }    
+                break;
+
+            default:
+                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a valid object")
+        } /* end switch */
+
+	/* Get the plist structure of object creation */
+	if(NULL == (plist = H5P_object_verify(ocpl_id, H5P_OBJECT_CREATE)))
+	    HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+	/* Check if the object creation property list uses the filter */
+	if((filter_in_pline = H5P_filter_in_pline(plist, filter_id)) < 0)
+	    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't check filter in pipeline")
+	
+        if(filter_in_pline)
+	    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't unregister filter because some object is still using it")
+    }
+
+    /* Count the number of opened files */
+    if(H5F_get_obj_count(NULL, H5F_OBJ_FILE, FALSE, &num_file_id) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get file number")
+   
+    /* Get the list of IDs for all opened files */ 
+    if(num_file_id) {
+        if(NULL == (file_list = (hid_t *)H5MM_malloc(num_file_id*sizeof(hid_t))))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "failed to allocate space")
+
+        if(H5F_get_obj_ids(NULL, H5F_OBJ_FILE, num_file_id, file_list, FALSE, &num_file_id) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get file IDs")
+    }
+
+    /* Flush all opened files in case any file uses the filter */
+    for(i=0; i<num_file_id; i++) {
+        if(NULL == (f = (H5F_t *)H5I_object_verify(file_list[i], H5I_FILE)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file")
+
+        /* Call the flush routine for mounted file hierarchies. Do a global flush 
+         * if the file is opened for write */
+        if(H5F_ACC_RDWR & H5F_INTENT(f)) {
+            if(H5F_flush_mounts(f, H5AC_dxpl_id) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file hierarchy")
+        } /* end if */
+    }
+
     /* Remove filter from table */
     /* Don't worry about shrinking table size (for now) */
-    HDmemmove(&H5Z_table_g[i],&H5Z_table_g[i+1],sizeof(H5Z_class2_t)*((H5Z_table_used_g-1)-i));
+    HDmemmove(&H5Z_table_g[filter_index],&H5Z_table_g[filter_index+1],sizeof(H5Z_class2_t)*((H5Z_table_used_g-1)-filter_index));
 #ifdef H5Z_DEBUG
-    HDmemmove(&H5Z_stat_table_g[i],&H5Z_stat_table_g[i+1],sizeof(H5Z_stats_t)*((H5Z_table_used_g-1)-i));
+    HDmemmove(&H5Z_stat_table_g[filter_index],&H5Z_stat_table_g[filter_index+1],sizeof(H5Z_stats_t)*((H5Z_table_used_g-1)-filter_index));
 #endif /* H5Z_DEBUG */
     H5Z_table_used_g--;
 
 done:
+    if(file_list) H5MM_free(file_list);
+    if(obj_id_list) H5MM_free(obj_id_list);
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5Z_unregister() */
 
@@ -1275,6 +1379,49 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5Z_filter_in_pline
+ *
+ * Purpose:	Check wheter a filter is in the filter pipeline using the 
+ *              filter ID.  This function is very similar to H5Z_filter_info
+ *
+ * Return:	TRUE   - found filter
+ *              FALSE  - not found
+ *              FAIL   - error
+ *
+ * Programmer:	Raymond Lu
+ *              26 April 2013
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5Z_filter_in_pline(const H5O_pline_t *pline, H5Z_filter_t filter)
+{
+    size_t	idx;                    /* Index of filter in pipeline */
+    htri_t      ret_value = TRUE;       /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    assert(pline);
+    assert(filter>=0 && filter<=H5Z_FILTER_MAX);
+
+    /* Locate the filter in the pipeline */
+    for(idx=0; idx<pline->nused; idx++)
+        if(pline->filter[idx].id==filter)
+            break;
+
+    /* Check if the filter was not already in the pipeline */
+    if(idx>=pline->nused)
+	ret_value = FALSE;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5Z_filter_in_pline() */
+
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5Z_all_filters_avail
  *
  * Purpose:	Verify that all the filters in a pipeline are currently
diff --git a/src/H5Zprivate.h b/src/H5Zprivate.h
index f53b50c..6c0a46f 100644
--- a/src/H5Zprivate.h
+++ b/src/H5Zprivate.h
@@ -91,6 +91,7 @@ H5_DLL herr_t H5Z_can_apply_direct(const struct H5O_pline_t *pline);
 H5_DLL herr_t H5Z_set_local_direct(const struct H5O_pline_t *pline);
 H5_DLL H5Z_filter_info_t *H5Z_filter_info(const struct H5O_pline_t *pline,
         H5Z_filter_t filter);
+H5_DLL htri_t H5Z_filter_in_pline(const struct H5O_pline_t *pline, H5Z_filter_t filter);
 H5_DLL htri_t H5Z_all_filters_avail(const struct H5O_pline_t *pline);
 H5_DLL htri_t H5Z_filter_avail(H5Z_filter_t id);
 H5_DLL herr_t H5Z_delete(struct H5O_pline_t *pline, H5Z_filter_t filter);
diff --git a/test/Makefile.am b/test/Makefile.am
index ac5d169..5e476d3 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -46,7 +46,7 @@ TEST_PROG= testhdf5 lheap ohdr stab gheap cache cache_api cache_tagging \
            big mtime fillval mount flush1 flush2 app_ref enum \
            set_extent ttsafe enc_dec_plist enc_dec_plist_with_endianess\
            getname vfd ntypes dangle dtransform reserved cross_read \
-           freespace mf farray earray btree2 fheap file_image
+           freespace mf farray earray btree2 fheap file_image unregister
 
 # List programs to be built when testing here. error_test and err_compat are
 # built at the same time as the other tests, but executed by testerror.sh.
@@ -150,7 +150,7 @@ CHECK_CLEANFILES+=accum.h5 cmpd_dset.h5 compact_dataset.h5 dataset.h5 dset_offse
     earray.h5 efc[0-5].h5 log_vfd_out.log                            \
     new_multi_file_v16-r.h5 new_multi_file_v16-s.h5                  \
     split_get_file_image_test-m.h5 split_get_file_image_test-r.h5    \
-    file_image_core_test.h5.copy
+    file_image_core_test.h5.copy unregister_filter_1.h5 unregister_filter_2.h5
 
 # Sources for testhdf5 executable
 testhdf5_SOURCES=testhdf5.c tarray.c tattr.c tchecksum.c tconfig.c tfile.c \
diff --git a/test/Makefile.in b/test/Makefile.in
index 65c0fca..e9e2faa 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -165,7 +165,8 @@ am__EXEEXT_1 = testhdf5$(EXEEXT) lheap$(EXEEXT) ohdr$(EXEEXT) \
 	vfd$(EXEEXT) ntypes$(EXEEXT) dangle$(EXEEXT) \
 	dtransform$(EXEEXT) reserved$(EXEEXT) cross_read$(EXEEXT) \
 	freespace$(EXEEXT) mf$(EXEEXT) farray$(EXEEXT) earray$(EXEEXT) \
-	btree2$(EXEEXT) fheap$(EXEEXT) file_image$(EXEEXT)
+	btree2$(EXEEXT) fheap$(EXEEXT) file_image$(EXEEXT) \
+	unregister$(EXEEXT)
 @HAVE_SHARED_CONDITIONAL_TRUE@am__EXEEXT_2 = plugin$(EXEEXT)
 am__EXEEXT_3 = gen_bad_ohdr$(EXEEXT) gen_bogus$(EXEEXT) \
 	gen_cross$(EXEEXT) gen_deflate$(EXEEXT) gen_filters$(EXEEXT) \
@@ -484,6 +485,10 @@ unlink_SOURCES = unlink.c
 unlink_OBJECTS = unlink.$(OBJEXT)
 unlink_LDADD = $(LDADD)
 unlink_DEPENDENCIES = libh5test.la $(LIBHDF5)
+unregister_SOURCES = unregister.c
+unregister_OBJECTS = unregister.$(OBJEXT)
+unregister_LDADD = $(LDADD)
+unregister_DEPENDENCIES = libh5test.la $(LIBHDF5)
 vfd_SOURCES = vfd.c
 vfd_OBJECTS = vfd.$(OBJEXT)
 vfd_LDADD = $(LDADD)
@@ -539,7 +544,7 @@ SOURCES = $(libdynlib1_la_SOURCES) $(libdynlib2_la_SOURCES) \
 	mount.c mtime.c ntypes.c objcopy.c ohdr.c plugin.c pool.c \
 	reserved.c set_extent.c space_overflow.c stab.c \
 	tcheck_version.c $(testhdf5_SOURCES) testmeta.c \
-	$(ttsafe_SOURCES) unlink.c vfd.c
+	$(ttsafe_SOURCES) unlink.c unregister.c vfd.c
 DIST_SOURCES = $(am__libdynlib1_la_SOURCES_DIST) \
 	$(am__libdynlib2_la_SOURCES_DIST) \
 	$(am__libdynlib3_la_SOURCES_DIST) $(libh5test_la_SOURCES) \
@@ -558,7 +563,7 @@ DIST_SOURCES = $(am__libdynlib1_la_SOURCES_DIST) \
 	mount.c mtime.c ntypes.c objcopy.c ohdr.c plugin.c pool.c \
 	reserved.c set_extent.c space_overflow.c stab.c \
 	tcheck_version.c $(testhdf5_SOURCES) testmeta.c \
-	$(ttsafe_SOURCES) unlink.c vfd.c
+	$(ttsafe_SOURCES) unlink.c unregister.c vfd.c
 am__can_run_installinfo = \
   case $$AM_UPDATE_INFO_DIR in \
     n|no|NO) false;; \
@@ -879,7 +884,8 @@ CHECK_CLEANFILES = *.chkexe *.chklog *.clog accum.h5 cmpd_dset.h5 \
 	objcopy_ext.dat trefer1.h5 trefer2.h5 app_ref.h5 farray.h5 \
 	earray.h5 efc[0-5].h5 log_vfd_out.log new_multi_file_v16-r.h5 \
 	new_multi_file_v16-s.h5 split_get_file_image_test-m.h5 \
-	split_get_file_image_test-r.h5 file_image_core_test.h5.copy
+	split_get_file_image_test-r.h5 file_image_core_test.h5.copy \
+	unregister_filter_1.h5 unregister_filter_2.h5
 INCLUDES = -I$(top_srcdir)/src -I$(top_builddir)/src
 
 # Test script for error_test and err_compat
@@ -902,7 +908,7 @@ TEST_PROG = testhdf5 lheap ohdr stab gheap cache cache_api cache_tagging \
            big mtime fillval mount flush1 flush2 app_ref enum \
            set_extent ttsafe enc_dec_plist enc_dec_plist_with_endianess\
            getname vfd ntypes dangle dtransform reserved cross_read \
-           freespace mf farray earray btree2 fheap file_image
+           freespace mf farray earray btree2 fheap file_image unregister
 
 
 # These programs generate test files for the tests.  They don't need to be
@@ -1303,6 +1309,9 @@ ttsafe$(EXEEXT): $(ttsafe_OBJECTS) $(ttsafe_DEPENDENCIES) $(EXTRA_ttsafe_DEPENDE
 unlink$(EXEEXT): $(unlink_OBJECTS) $(unlink_DEPENDENCIES) $(EXTRA_unlink_DEPENDENCIES) 
 	@rm -f unlink$(EXEEXT)
 	$(AM_V_CCLD)$(LINK) $(unlink_OBJECTS) $(unlink_LDADD) $(LIBS)
+unregister$(EXEEXT): $(unregister_OBJECTS) $(unregister_DEPENDENCIES) $(EXTRA_unregister_DEPENDENCIES) 
+	@rm -f unregister$(EXEEXT)
+	$(AM_V_CCLD)$(LINK) $(unregister_OBJECTS) $(unregister_LDADD) $(LIBS)
 vfd$(EXEEXT): $(vfd_OBJECTS) $(vfd_DEPENDENCIES) $(EXTRA_vfd_DEPENDENCIES) 
 	@rm -f vfd$(EXEEXT)
 	$(AM_V_CCLD)$(LINK) $(vfd_OBJECTS) $(vfd_LDADD) $(LIBS)
@@ -1421,6 +1430,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/tvlstr.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/tvltypes.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/unlink.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/unregister.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/vfd.Po@am__quote@
 
 .c.o:
diff --git a/test/unregister.c b/test/unregister.c
new file mode 100644
index 0000000..88f4d1b
--- /dev/null
+++ b/test/unregister.c
@@ -0,0 +1,258 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5. The full HDF5 copyright notice, including      *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic 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.            *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+/*
+ * Programmer:	Raymond Lu
+ *              24 April 2013
+ *
+ * Purpose:	Tests H5Zunregister function
+ */
+#include "h5test.h"
+
+const char *FILENAME[] = {
+    "unregister_filter_1",
+    "unregister_filter_2",
+    NULL
+};
+
+#define GROUP_NAME              "group"
+#define DSET_NAME               "dataset"
+#define FILENAME_BUF_SIZE       1024
+#define DSET_DIM1               100
+#define DSET_DIM2               200
+#define FILTER_CHUNK_DIM1       2
+#define FILTER_CHUNK_DIM2       25
+#define GROUP_ITERATION         1000
+
+#define H5Z_FILTER_DUMMY        312
+
+static size_t filter_dummy(unsigned int flags, size_t cd_nelmts,
+    const unsigned int *cd_values, size_t nbytes, size_t *buf_size, void **buf);
+
+/* Dummy filter for test_unregister_filters only */
+const H5Z_class2_t H5Z_DUMMY[1] = {{
+    H5Z_CLASS_T_VERS,           /* H5Z_class_t version */
+    H5Z_FILTER_DUMMY,		/* Filter id number		*/
+    1, 1,                       /* Encoding and decoding enabled */
+    "dummy",			/* Filter name for debugging	*/
+    NULL,                       /* The "can apply" callback     */
+    NULL,                       /* The "set local" callback     */
+    filter_dummy,		/* The actual filter function	*/
+}};
+
+
+/*-------------------------------------------------------------------------
+ * Function:	filter_dummy
+ *
+ * Purpose:	A dummy compression method that doesn't do anything.  This
+ *              filter is only for test_unregister_filters.  Please don't 
+ *              use it for other tests because it may mess up this test.
+ *
+ * Return:	Success:	Data chunk size
+ *
+ *		Failure:	0
+ *
+ * Programmer:	Raymond Lu
+ *              April 24, 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static size_t
+filter_dummy(unsigned int UNUSED flags, size_t UNUSED cd_nelmts,
+      const unsigned int UNUSED *cd_values, size_t nbytes,
+      size_t UNUSED *buf_size, void UNUSED **buf)
+{
+    return nbytes;
+}
+
+/*-------------------------------------------------------------------------
+ * Function:	test_unregister_filters
+ *
+ * Purpose:	Tests unregistering filter before closing the file
+ *
+ * Return:	Success:	0
+ *		Failure:	-1
+ *
+ * Programmer:	Raymond Lu
+ *              11 April 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+test_unregister_filters(hid_t my_fapl)
+{
+    hid_t	file1, file2;
+    hid_t	dc;
+    hid_t	gcpl, gid, group;
+    hid_t       dataset, space;
+    int		i, j, n;
+    char        gname[256];
+    char        filename[FILENAME_BUF_SIZE];
+    const hsize_t chunk_size[2] = {FILTER_CHUNK_DIM1, FILTER_CHUNK_DIM2};  /* Chunk dimensions */
+    hsize_t	dims[2];
+    int	        points[DSET_DIM1][DSET_DIM2];
+    herr_t      ret;
+
+    TESTING("Unregistering filter");
+
+    /* Create first file */
+    h5_fixname(FILENAME[0], my_fapl, filename, sizeof filename);
+    if((file1 = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, my_fapl)) < 0) goto error;
+
+    /* Create second file */
+    h5_fixname(FILENAME[1], my_fapl, filename, sizeof filename);
+    if((file2 = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, my_fapl)) < 0) goto error;
+
+    /* Register DUMMY filter */
+    if(H5Zregister(H5Z_DUMMY) < 0) goto error;
+
+    if(H5Zfilter_avail(H5Z_FILTER_DUMMY)!=TRUE) goto error;
+
+    if((gcpl = H5Pcreate(H5P_GROUP_CREATE)) < 0) goto error;
+  
+    /* Use DUMMY filter for creating groups */ 
+    if(H5Pset_filter (gcpl, H5Z_FILTER_DUMMY, H5Z_FLAG_MANDATORY, (size_t)0, NULL) < 0) goto error;
+
+    /* Create a group using this filter */
+    if((gid = H5Gcreate2(file1, GROUP_NAME, H5P_DEFAULT, gcpl, H5P_DEFAULT)) < 0) goto error;
+
+    /* Create multiple groups under the main group */
+    for (i=0; i < GROUP_ITERATION; i++) {
+        sprintf(gname, "group_%d", i);
+        if((group = H5Gcreate2(gid, gname, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) goto error;
+        if(H5Gclose(group) < 0) goto error; 
+    }
+
+    if(H5Fflush(file1, H5F_SCOPE_GLOBAL) < 0) goto error;
+
+    /* Unregister the filter before closing the group.  It should fail */
+    H5E_BEGIN_TRY {
+        ret = H5Zunregister(H5Z_FILTER_DUMMY);
+    } H5E_END_TRY;
+    if(ret>=0) {
+        H5_FAILED();
+        printf("    Line %d: Should not be able to unregister filter\n", __LINE__);
+        goto error;
+    } /* end if */
+
+
+    /* Close the group */
+    if(H5Gclose(gid) < 0) goto error;
+
+    /* Clean up objects used for this test */
+    if(H5Pclose (gcpl) < 0) goto error;
+
+    if((dc = H5Pcreate(H5P_DATASET_CREATE)) < 0) goto error;
+    if(H5Pset_chunk (dc, 2, chunk_size) < 0) goto error;
+
+    if(H5Pset_filter(dc, H5Z_FILTER_DUMMY, 0, (size_t)0, NULL) < 0) goto error;
+
+    /* Initialize the dataset */
+    for(i = n = 0; i < DSET_DIM1; i++)
+        for(j = 0; j < DSET_DIM2; j++)
+            points[i][j] = n++;
+
+    /* Create the data space */
+    dims[0] = DSET_DIM1;
+    dims[1] = DSET_DIM2;
+    if((space = H5Screate_simple(2, dims, NULL)) < 0) goto error;
+
+    /* Create a dataset in the first file */
+    if((dataset = H5Dcreate2(file1, DSET_NAME, H5T_NATIVE_INT, space,
+                             H5P_DEFAULT, dc, H5P_DEFAULT)) < 0) goto error;
+
+    /* Write the data to the dataset */
+    if(H5Dwrite(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, points) < 0)
+        goto error;
+
+    /* Unregister the filter before closing the dataset.  It should fail */
+    /*if(H5Zunregister(H5Z_FILTER_DUMMY) < 0) goto error;*/
+    H5E_BEGIN_TRY {
+        ret = H5Zunregister(H5Z_FILTER_DUMMY);
+    } H5E_END_TRY;
+    if(ret>=0) {
+        H5_FAILED();
+        printf("    Line %d: Should not be able to unregister filter\n", __LINE__);
+        goto error;
+    } /* end if */
+
+    if(H5Dclose(dataset) < 0) goto error;
+
+    /* Create a dataset in the second file */
+    if((dataset = H5Dcreate2(file2, DSET_NAME, H5T_NATIVE_INT, space,
+                             H5P_DEFAULT, dc, H5P_DEFAULT)) < 0) goto error;
+
+    /* Write the data to the dataset */
+    if(H5Dwrite(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, points) < 0)
+        goto error;
+
+    if(H5Dclose(dataset) < 0) goto error;
+
+    /* Unregister the filter after closing all objects but before closing files. 
+     * It should flush all files. */
+    if(H5Zunregister(H5Z_FILTER_DUMMY) < 0) goto error;
+
+    /* Clean up objects used for this test */
+    if(H5Pclose (dc) < 0) goto error;
+    if(H5Fclose(file1) < 0) goto error;
+    if(H5Fclose(file2) < 0) goto error;
+
+    PASSED();
+    return 0;
+
+error:
+    return -1;
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	main
+ *
+ * Purpose:	Tests unregistering filter with H5Zunregister
+ *
+ * Return:	Success:	exit(0)
+ *
+ *		Failure:	exit(1)
+ *
+ * Programmer:	Raymond Lu
+ *              11 April 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+main(void)
+{
+    hid_t		fapl;
+    int	nerrors = 0;
+
+    /* Testing setup */
+    h5_reset();
+    fapl = h5_fileaccess();
+
+    /* Test unregistering filter in its own file */
+    nerrors += (test_unregister_filters(fapl) < 0           ? 1 : 0);
+
+    if(nerrors)
+        goto error;
+    printf("All dataset tests passed.\n");
+    h5_cleanup(FILENAME, fapl);
+
+    return 0;
+
+error:
+    nerrors = MAX(1, nerrors);
+    printf("***** %d DATASET TEST%s FAILED! *****\n",
+            nerrors, 1 == nerrors ? "" : "S");
+    return 1;
+}
+