[svn-r19133] Description:

	Correct traversal of user-defined links (including external links) to
retain path information of object, allowing H5Iget_name() queries to work
quickly (without searching entire destination file).  This required some
refactoring and addition of a mechanism to detect if a "fast" query was
performed (for the tests).

	Minor code cleanups, etc.

Tested on:
        FreeBSD/32 6.3 (duty) in debug mode
        FreeBSD/64 6.3 (liberty) 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 (amani) w/Intel compilers, w/default API=1.6.x,
                w/C++ & FORTRAN, in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                w/szip filter, w/threadsafe, in production mode
        Linux/PPC 2.6 (heiwa) w/C++ & FORTRAN, w/threadsafe, in debug mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                in production mode
        Linux/64-amd64 2.6 (abe) w/parallel, w/FORTRAN, in debug mode
        Mac OS X/32 10.6.4 (amazon) in debug mode
        Mac OS X/32 10.6.4 (amazon) w/C++ & FORTRAN, w/threadsafe,
                in production mode
        Mac OS X/32 10.6.4 (amazon) w/parallel, in debug mode

10 files changed, 234 insertions, 152 deletions

diff --git a/src/H5Dtest.c b/src/H5Dtest.c
index a933c88..0a69ff7 100644
--- a/src/H5Dtest.c
+++ b/src/H5Dtest.c
@@ -14,7 +14,7 @@
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /* Programmer:  Quincey Koziol <koziol@ncsa.uiuc.edu>
- *              Thusdayr, May 27, 2004
+ *              Thursday, May 27, 2004
  *
  * Purpose:	Dataset testing functions.
  */
diff --git a/src/H5Gname.c b/src/H5Gname.c
index b298ccf..96b2e3a 100644
--- a/src/H5Gname.c
+++ b/src/H5Gname.c
@@ -426,49 +426,57 @@ H5G_name_copy(H5G_name_t *dst, const H5G_name_t *src, H5_copy_depth_t depth)
  *-------------------------------------------------------------------------
  */
 ssize_t
-H5G_get_name(hid_t id, char *name/*out*/, size_t size, hid_t lapl_id,
-    hid_t dxpl_id)
+H5G_get_name(const H5G_loc_t *loc, char *name/*out*/, size_t size,
+    hbool_t *cached, hid_t lapl_id, hid_t dxpl_id)
 {
-    H5G_loc_t     loc;          /* Object location */
-    ssize_t       ret_value = FAIL;
+    ssize_t len = 0;            /* Length of object's name */
+    ssize_t ret_value;          /* Return value */
 
     FUNC_ENTER_NOAPI(H5G_get_name, FAIL)
 
-    /* get object location */
-    if(H5G_loc(id, &loc) >= 0) {
-        ssize_t len = 0;
+    /* Sanity check */
+    HDassert(loc);
 
-        /* If the user path is available and it's not "hidden", use it */
-        if(loc.path->user_path_r != NULL && loc.path->obj_hidden == 0) {
-            len = H5RS_len(loc.path->user_path_r);
+    /* If the user path is available and it's not "hidden", use it */
+    if(loc->path->user_path_r != NULL && loc->path->obj_hidden == 0) {
+        len = H5RS_len(loc->path->user_path_r);
 
-            if(name) {
-                HDstrncpy(name, H5RS_get_str(loc.path->user_path_r), MIN((size_t)(len + 1), size));
-                if((size_t)len >= size)
-                    name[size - 1] = '\0';
-            } /* end if */
+        if(name) {
+            HDstrncpy(name, H5RS_get_str(loc->path->user_path_r), MIN((size_t)(len + 1), size));
+            if((size_t)len >= size)
+                name[size - 1] = '\0';
         } /* end if */
-	else if(!loc.path->obj_hidden) {
-	    hid_t	  file;
 
-            /* Retrieve file ID for name search */
-	    if((file = H5I_get_file_id(id, FALSE)) < 0)
-		HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't retrieve file ID")
+        /* Indicate that the name is cached, if requested */
+        /* (Currently only used for testing - QAK, 2010/07/26) */
+        if(cached)
+            *cached = TRUE;
+    } /* end if */
+    else if(!loc->path->obj_hidden) {
+        hid_t	  file;
 
-            /* Search for name of object */
-	    if((len = H5G_get_name_by_addr(file, lapl_id, dxpl_id, loc.oloc, name, size)) < 0) {
-                H5I_dec_ref(file, FALSE);
-		HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't determine name")
-            } /* end if */
+        /* Retrieve file ID for name search */
+        if((file = H5F_get_id(loc->oloc->file, FALSE)) < 0)
+            HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't get file ID")
 
-            /* Close file ID used for search */
-	    if(H5I_dec_ref(file, FALSE) < 0)
-		HGOTO_ERROR(H5E_SYM, H5E_CANTCLOSEFILE, FAIL, "can't determine name")
-	} /* end else */
+        /* Search for name of object */
+        if((len = H5G_get_name_by_addr(file, lapl_id, dxpl_id, loc->oloc, name, size)) < 0) {
+            H5I_dec_ref(file, FALSE);
+            HGOTO_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "can't determine name")
+        } /* end if */
 
-        /* Set return value */
-        ret_value = len;
-    } /* end if */
+        /* Close file ID used for search */
+        if(H5I_dec_ref(file, FALSE) < 0)
+            HGOTO_ERROR(H5E_SYM, H5E_CANTCLOSEFILE, FAIL, "can't determine name")
+
+        /* Indicate that the name is _not_ cached, if requested */
+        /* (Currently only used for testing - QAK, 2010/07/26) */
+        if(cached)
+            *cached = FALSE;
+    } /* end else */
+
+    /* Set return value */
+    ret_value = len;
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5Gprivate.h b/src/H5Gprivate.h
index 3e66777..7b09423 100644
--- a/src/H5Gprivate.h
+++ b/src/H5Gprivate.h
@@ -196,8 +196,8 @@ H5_DLL herr_t H5G_name_replace(const struct H5O_link_t *lnk, H5G_names_op_t op,
 H5_DLL herr_t H5G_name_reset(H5G_name_t *name);
 H5_DLL herr_t H5G_name_copy(H5G_name_t *dst, const H5G_name_t *src, H5_copy_depth_t depth);
 H5_DLL herr_t H5G_name_free(H5G_name_t *name);
-H5_DLL ssize_t H5G_get_name(hid_t id, char *name/*out*/, size_t size,
-    hid_t lapl_id, hid_t dxpl_id);
+H5_DLL ssize_t H5G_get_name(const H5G_loc_t *loc, char *name/*out*/, size_t size,
+    hbool_t *cached, hid_t lapl_id, hid_t dxpl_id);
 H5_DLL ssize_t H5G_get_name_by_addr(hid_t fid, hid_t lapl_id, hid_t dxpl_id,
     const struct H5O_loc_t *loc, char* name, size_t size);
 
diff --git a/src/H5Gtraverse.c b/src/H5Gtraverse.c
index 5b1f71c..61c08fa 100644
--- a/src/H5Gtraverse.c
+++ b/src/H5Gtraverse.c
@@ -171,8 +171,7 @@ H5G_traverse_ud(const H5G_loc_t *grp_loc/*in,out*/, const H5O_link_t *lnk,
     H5G_loc_t           grp_loc_copy;
     H5G_name_t          grp_path_copy;
     H5O_loc_t           grp_oloc_copy;
-    H5O_loc_t          *new_oloc = NULL;
-    H5F_t              *temp_file = NULL;
+    H5G_loc_t           new_loc;                /* Group location for newly opened external object */
     H5G_t              *grp;
     hid_t               lapl_id = (-1);         /* LAPL local to this routine */
     H5P_genplist_t     *lapl;                   /* LAPL with nlinks set */
@@ -189,13 +188,9 @@ H5G_traverse_ud(const H5G_loc_t *grp_loc/*in,out*/, const H5O_link_t *lnk,
     HDassert(nlinks);
     HDassert(_lapl_id >= 0);
 
-    /* Reset the object's path information, because we can't detect any changes
-     * in the "path" the user-defined callback takes */
-    H5G_name_free(obj_loc->path);
-
     /* Get the link class for this type of link. */
     if(NULL == (link_class = H5L_find_class(lnk->type)))
-        HGOTO_ERROR(H5E_LINK, H5E_NOTREGISTERED, FAIL, "unable to get UD link class")
+        HGOTO_ERROR(H5E_SYM, H5E_NOTREGISTERED, FAIL, "unable to get UD link class")
 
     /* Set up location for user-defined callback.  Use a copy of our current
      * grp_loc. */
@@ -203,37 +198,37 @@ H5G_traverse_ud(const H5G_loc_t *grp_loc/*in,out*/, const H5O_link_t *lnk,
     grp_loc_copy.oloc = &grp_oloc_copy;
     H5G_loc_reset(&grp_loc_copy);
     if(H5G_loc_copy(&grp_loc_copy, grp_loc, H5_COPY_DEEP) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTCOPY, FAIL, "unable to copy object location")
+        HGOTO_ERROR(H5E_SYM, H5E_CANTCOPY, FAIL, "unable to copy object location")
 
-    /* Create a group to pass to the user-defined callback */
-    if((grp = H5G_open(&grp_loc_copy, dxpl_id)) == NULL)
+    /* Create a group ID to pass to the user-defined callback */
+    if(NULL == (grp = H5G_open(&grp_loc_copy, dxpl_id)))
         HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open group")
     if((cur_grp = H5I_register(H5I_GROUP, grp, FALSE)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register group")
+        HGOTO_ERROR(H5E_SYM, H5E_CANTREGISTER, FAIL, "unable to register group")
 
     /* Check for generic default property list and use link access default if so */
     if(_lapl_id == H5P_DEFAULT) {
         HDassert(H5P_LINK_ACCESS_DEFAULT != -1);
         if(NULL == (lapl = (H5P_genplist_t *)H5I_object(H5P_LINK_ACCESS_DEFAULT)))
-            HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "unable to get default property list")
+            HGOTO_ERROR(H5E_SYM, H5E_BADATOM, FAIL, "unable to get default property list")
     } /* end if */
     else {
         /* Get the underlying property list passed in */
         if(NULL == (lapl = (H5P_genplist_t *)H5I_object(_lapl_id)))
-            HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "unable to get property list from ID")
+            HGOTO_ERROR(H5E_SYM, H5E_BADATOM, FAIL, "unable to get property list from ID")
     } /* end else */
 
     /* Copy the property list passed in */
     if((lapl_id = H5P_copy_plist(lapl, FALSE)) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "unable to copy property list")
+        HGOTO_ERROR(H5E_SYM, H5E_CANTCOPY, FAIL, "unable to copy property list")
 
     /* Get the underlying property list copy */
     if(NULL == (lapl = (H5P_genplist_t *)H5I_object(lapl_id)))
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "unable to get property list from ID")
+        HGOTO_ERROR(H5E_SYM, H5E_BADATOM, FAIL, "unable to get property list from ID")
 
     /* Record number of soft links left to traverse in the property list. */
     if(H5P_set(lapl, H5L_ACS_NLINKS_NAME, nlinks) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set nlink info")
+        HGOTO_ERROR(H5E_SYM, H5E_CANTSET, FAIL, "can't set nlink info")
 
     /* User-defined callback function */
     cb_return = (link_class->trav_func)(lnk->name, cur_grp, lnk->u.ud.udata, lnk->u.ud.size, lapl_id);
@@ -253,79 +248,45 @@ H5G_traverse_ud(const H5G_loc_t *grp_loc/*in,out*/, const H5O_link_t *lnk,
         } /* end if */
         /* else, we really needed to open the object */
         else
-            HGOTO_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "traversal callback returned invalid ID")
+            HGOTO_ERROR(H5E_SYM, H5E_BADATOM, FAIL, "traversal callback returned invalid ID")
     } /* end if */
 
-    /* Get the oloc from the ID the user callback returned */
-    switch(H5I_get_type(cb_return)) {
-        case H5I_GROUP:
-            if((new_oloc = H5G_oloc((H5G_t *)H5I_object(cb_return))) == NULL)
-                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get object location from group ID")
-                break;
-
-        case H5I_DATASET:
-            if((new_oloc = H5D_oloc((H5D_t *)H5I_object(cb_return))) ==NULL)
-                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get object location from dataset ID")
-                break;
-
-        case H5I_DATATYPE:
-            if((new_oloc = H5T_oloc((H5T_t *)H5I_object(cb_return))) ==NULL)
-                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get object location from datatype ID")
-                break;
-
-        case H5I_FILE:
-            if((temp_file = (H5F_t *)H5I_object(cb_return)) == NULL)
-                HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "couldn't get file from ID")
-            if((new_oloc = H5G_oloc(temp_file->shared->root_grp)) ==NULL)
-                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get root group location from file ID")
-                break;
-
-        case H5I_UNINIT:
-        case H5I_BADID:
-        case H5I_DATASPACE:
-        case H5I_ATTR:
-        case H5I_REFERENCE:
-        case H5I_VFL:
-        case H5I_GENPROP_CLS:
-        case H5I_GENPROP_LST:
-        case H5I_ERROR_CLASS:
-        case H5I_ERROR_MSG:
-        case H5I_ERROR_STACK:
-        case H5I_NTYPES:
-        default:
-            HGOTO_ERROR(H5E_ATOM, H5E_BADTYPE, FAIL, "not a valid location or object ID")
-    } /* end switch */
-
-    /* Copy the location the user returned to us */
-    if(H5O_loc_copy(obj_loc->oloc, new_oloc, H5_COPY_DEEP) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTCOPY, FAIL, "unable to copy object location")
+    /* Get the object location information from the ID the user callback returned */
+    if(H5G_loc(cb_return, &new_loc) < 0)
+        HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, FAIL, "unable to get object location from ID")
+
+    /* Release any previous location information for the object */
+    H5G_loc_free(obj_loc);
+
+    /* Copy new object's location information */
+    H5G_loc_copy(obj_loc, &new_loc, H5_COPY_DEEP);
 
     /* Hold the file open until we free this object header (otherwise the
      * object location will be invalidated when the file closes).
      */
     if(H5O_loc_hold_file(obj_loc->oloc) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "unable to hold file open")
+        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to hold file open")
 
     /* We have a copy of the location and we're holding the file open.
      * Close the open ID the user passed back.
      */
     if(H5I_dec_ref(cb_return, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTRELEASE, FAIL, "unable to close atom from UD callback")
+        HGOTO_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close atom from UD callback")
     cb_return = (-1);
 
 done:
     /* Close location given to callback. */
     if(cur_grp > 0)
         if(H5I_dec_ref(cur_grp, FALSE) < 0)
-            HDONE_ERROR(H5E_ATOM, H5E_CANTRELEASE, FAIL, "unable to close atom for current location")
+            HDONE_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close atom for current location")
 
     if(ret_value < 0 && cb_return > 0)
         if(H5I_dec_ref(cb_return, FALSE) < 0)
-            HDONE_ERROR(H5E_ATOM, H5E_CANTRELEASE, FAIL, "unable to close atom from UD callback")
+            HDONE_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close atom from UD callback")
 
     /* Close the LAPL, if we copied one */
     if(lapl_id > 0 && H5I_dec_ref(lapl_id, FALSE) < 0)
-        HDONE_ERROR(H5E_ATOM, H5E_CANTRELEASE, FAIL, "unable to close copied link access property list")
+        HDONE_ERROR(H5E_SYM, H5E_CANTRELEASE, FAIL, "unable to close copied link access property list")
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5G_traverse_ud() */
@@ -573,7 +534,7 @@ H5G_traverse_special(const H5G_loc_t *grp_loc, const H5O_link_t *lnk,
      */
     if(grp_loc->oloc->holding_file && grp_loc->oloc->file == obj_loc->oloc->file)
         if(H5O_loc_hold_file(obj_loc->oloc) < 0)
-            HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "unable to hold file open")
+            HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to hold file open")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -845,7 +806,7 @@ H5G_traverse_real(const H5G_loc_t *_loc, const char *name, unsigned target,
                  */
                 if(grp_loc.oloc->holding_file)
                     if(H5O_loc_hold_file(obj_loc.oloc) < 0)
-                        HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "unable to hold file open")
+                        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to hold file open")
             } /* end if */
             else
                 HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "component not found")
diff --git a/src/H5I.c b/src/H5I.c
index d6655e0..be3c9d6 100644
--- a/src/H5I.c
+++ b/src/H5I.c
@@ -896,7 +896,7 @@ H5I_register(H5I_type_t type, const void *object, hbool_t app_ref)
 
 	    /* new ID to check for */
 	    next_id = H5I_MAKE(type, type_ptr->nextid);
-	    hash_loc = H5I_LOC(type_ptr->nextid, type_ptr->hash_size);
+	    hash_loc = (unsigned)H5I_LOC(type_ptr->nextid, type_ptr->hash_size);
 	    curr_id = type_ptr->id_list[hash_loc];
 	    if(curr_id == NULL)
                 break; /* Ha! this is not likely... */
@@ -1421,15 +1421,16 @@ H5I_dec_ref(hid_t id, hbool_t app_ref)
         if(!type_ptr->free_func || (type_ptr->free_func)((void *)id_ptr->obj_ptr) >= 0) {
             H5I_remove(id);
             ret_value = 0;
-        } else {
+        } /* end if */
+        else
             ret_value = FAIL;
-        }
-    } else {
+    } /* end if */
+    else {
         --(id_ptr->count);
-        if (app_ref)
+        if(app_ref)
             --(id_ptr->app_count);
         HDassert(id_ptr->count >= id_ptr->app_count);
-        ret_value = app_ref ? id_ptr->app_count : id_ptr->count;
+        ret_value = (int)(app_ref ? id_ptr->app_count : id_ptr->count);
     }
 
 done:
@@ -1525,7 +1526,7 @@ H5I_inc_ref(hid_t id, hbool_t app_ref)
         ++(id_ptr->app_count);
 
     /* Set return value */
-    ret_value = app_ref ? id_ptr->app_count : id_ptr->count;
+    ret_value = (int)(app_ref ? id_ptr->app_count : id_ptr->count);
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1615,7 +1616,7 @@ H5I_get_ref(hid_t id, hbool_t app_ref)
 	HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't locate ID")
 
     /* Set return value */
-    ret_value = app_ref ? id_ptr->app_count : id_ptr->count;
+    ret_value = (int)(app_ref ? id_ptr->app_count : id_ptr->count);
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1696,7 +1697,7 @@ H5I_inc_type_ref(H5I_type_t type)
 	HGOTO_ERROR(H5E_ATOM, H5E_BADGROUP, FAIL, "invalid type")
 
     /* Set return value */
-    ret_value = ++(type_ptr->count);
+    ret_value = (int)(++(type_ptr->count));
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1797,7 +1798,7 @@ H5I_dec_type_ref(H5I_type_t type)
     } /* end if */
     else {
         --(type_ptr->count);
-        ret_value = type_ptr->count;
+        ret_value = (herr_t)type_ptr->count;
     } /* end else */
 
 done:
@@ -1879,7 +1880,7 @@ H5I_get_type_ref(H5I_type_t type)
         HGOTO_ERROR(H5E_ATOM, H5E_BADGROUP, FAIL, "invalid type")
 
     /* Set return value */
-    ret_value = type_ptr->count;
+    ret_value = (int)type_ptr->count;
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -2133,13 +2134,18 @@ done:
 ssize_t
 H5Iget_name(hid_t id, char *name/*out*/, size_t size)
 {
+    H5G_loc_t     loc;          /* Object location */
     ssize_t       ret_value;    /* Return value */
 
     FUNC_ENTER_API(H5Iget_name, FAIL)
     H5TRACE3("Zs", "ixz", id, name, size);
 
+    /* Get object location */
+    if(H5G_loc(id, &loc) < 0)
+	HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't retrieve object location")
+
     /* Call internal group routine to retrieve object's name */
-    if((ret_value = H5G_get_name(id, name, size, H5P_DEFAULT, H5AC_ind_dxpl_id)) < 0)
+    if((ret_value = H5G_get_name(&loc, name, size, NULL, H5P_DEFAULT, H5AC_ind_dxpl_id)) < 0)
 	HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't retrieve object name")
 
 done:
@@ -2187,7 +2193,6 @@ done:
  *              ID given an object ID.
  *
  * Return:	Success:	file ID
- *
  *		Failure:	a negative value
  *
  * Programmer:  Raymond Lu
@@ -2198,7 +2203,6 @@ done:
 hid_t
 H5I_get_file_id(hid_t obj_id, hbool_t app_ref)
 {
-    H5G_loc_t loc;              /* Location of object */
     H5I_type_t type;            /* ID type */
     hid_t ret_value;            /* Return value */
 
@@ -2207,18 +2211,24 @@ H5I_get_file_id(hid_t obj_id, hbool_t app_ref)
     /* Get object type */
     type = H5I_TYPE(obj_id);
     if(type == H5I_FILE) {
-        ret_value = obj_id;
-
-        /* Increment reference count on atom. */
-        if(H5I_inc_ref(ret_value, app_ref) < 0)
+        /* Increment reference count on file ID */
+        if(H5I_inc_ref(obj_id, app_ref) < 0)
             HGOTO_ERROR(H5E_ATOM, H5E_CANTSET, FAIL, "incrementing file ID failed")
-    }
+
+        /* Set return value */
+        ret_value = obj_id;
+    } /* end if */
     else if(type == H5I_DATATYPE || type == H5I_GROUP || type == H5I_DATASET || type == H5I_ATTR) {
+        H5G_loc_t loc;              /* Location of object */
+
+        /* Get the object location information */
         if(H5G_loc(obj_id, &loc) < 0)
             HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't get object location")
+
+        /* Get the file ID for the object */
         if((ret_value = H5F_get_id(loc.oloc->file, app_ref)) < 0)
             HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't get file ID")
-    }
+    } /* end if */
     else
         HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL, "invalid object ID")
 
diff --git a/src/H5Ipkg.h b/src/H5Ipkg.h
index e86f134..f17a4b0 100644
--- a/src/H5Ipkg.h
+++ b/src/H5Ipkg.h
@@ -67,4 +67,10 @@
 /* Package Private Prototypes */
 /******************************/
 
+/* Testing functions */
+#ifdef H5I_TESTING
+H5_DLL ssize_t H5I_get_name_test(hid_t id, char *name/*out*/, size_t size,
+    hbool_t *cached);
+#endif /* H5I_TESTING */
+
 #endif /*_H5Ipkg_H*/
diff --git a/src/H5Itest.c b/src/H5Itest.c
new file mode 100644
index 0000000..1c6892d
--- /dev/null
+++ b/src/H5Itest.c
@@ -0,0 +1,98 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * 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 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.     *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/* Programmer:  Quincey Koziol <koziol@hdfgoup.org>
+ *              Tuesday, July 27, 2010
+ *
+ * Purpose:	ID testing functions.
+ */
+
+/****************/
+/* Module Setup */
+/****************/
+
+#define H5I_PACKAGE		/*suppress error about including H5Ipkg	  */
+#define H5I_TESTING		/*suppress warning about H5I testing funcs*/
+
+
+/***********/
+/* Headers */
+/***********/
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5ACprivate.h"        /* Metadata cache                       */
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5Gprivate.h"		/* Groups				*/
+#include "H5Ipkg.h"		/* IDs			  		*/
+
+
+/****************/
+/* Local Macros */
+/****************/
+
+
+/******************/
+/* Local Typedefs */
+/******************/
+
+
+/********************/
+/* Local Prototypes */
+/********************/
+
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+
+/*******************/
+/* Local Variables */
+/*******************/
+
+
+
+/*-------------------------------------------------------------------------
+ * Function: H5I_get_name_test
+ *
+ * Purpose: Testing version of H5Iget_name()
+ *
+ * Return: Success: The length of name.
+ *         Failure: -1
+ *
+ * Programmer:	Quincey Koziol
+ *              Tuesday, July 27, 2010
+ *
+ *-------------------------------------------------------------------------
+ */
+ssize_t
+H5I_get_name_test(hid_t id, char *name/*out*/, size_t size, hbool_t *cached)
+{
+    H5G_loc_t     loc;          /* Object location */
+    ssize_t       ret_value;    /* Return value */
+
+    FUNC_ENTER_NOAPI(H5I_get_name_test, FAIL)
+
+    /* Get object location */
+    if(H5G_loc(id, &loc) < 0)
+	HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't retrieve object location")
+
+    /* Call internal group routine to retrieve object's name */
+    if((ret_value = H5G_get_name(&loc, name, size, cached, H5P_DEFAULT, H5AC_ind_dxpl_id)) < 0)
+	HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't retrieve object name")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5I_get_name_test() */
+
diff --git a/src/H5Lexternal.c b/src/H5Lexternal.c
index c5ae92f..d98a843 100644
--- a/src/H5Lexternal.c
+++ b/src/H5Lexternal.c
@@ -53,6 +53,9 @@ const H5L_class_t H5L_EXTERN_LINK_CLASS[1] = {{
 /* Valid flags for external links */
 #define H5L_EXT_FLAGS_ALL       0
 
+/* Size of local link name buffer for traversing external links */
+#define H5L_EXT_TRAVERSE_BUF_SIZE       256
+
 
 /*--------------------------------------------------------------------------
 NAME
@@ -205,7 +208,8 @@ H5L_extern_traverse(const char UNUSED *link_name, hid_t cur_group,
     H5L_elink_cb_t cb_info;             /* Callback info struct */
     hid_t       fapl_id = -1;           /* File access property list for external link's file */
     hid_t       ext_obj = -1;           /* ID for external link's object */
-    char        *temp_group_name = NULL;/* Temporary pointer to group name */
+    char        *parent_group_name = NULL;/* Temporary pointer to group name */
+    char        local_group_name[H5L_EXT_TRAVERSE_BUF_SIZE];  /* Local buffer to hold group name */
     char        *temp_file_name = NULL; /* Temporary pointer to file name */
     char        *actual_file_name = NULL; /* Parent file's actual name */
     H5P_genplist_t  *fa_plist;          /* File access property list pointer */
@@ -264,41 +268,34 @@ H5L_extern_traverse(const char UNUSED *link_name, hid_t cur_group,
     /* Make callback if it exists */
     if(cb_info.func) {
         const char  *parent_file_name;  /* Parent file name */
-        const char  *parent_group_name; /* Parent group name */
+        ssize_t group_name_len;         /* Length of parent group name */
 
         /* Get parent file name */
         parent_file_name = H5F_OPEN_NAME(loc.oloc->file);
 
+        /* Query length of parent group name */
+        if((group_name_len = H5G_get_name(&loc, NULL, (size_t) 0, NULL, lapl_id, H5AC_ind_dxpl_id)) < 0)
+            HGOTO_ERROR(H5E_LINK, H5E_CANTGET, FAIL, "unable to retrieve length of group name")
+
+        /* Account for null terminator */
+        group_name_len++;
+
+        /* Check if we need to allocate larger buffer */
+        if((size_t)group_name_len > sizeof(local_group_name)) {
+            if(NULL == (parent_group_name = (char *)H5MM_malloc((size_t)group_name_len)))
+                HGOTO_ERROR(H5E_LINK, H5E_CANTALLOC, FAIL, "can't allocate buffer to hold group name, group_name_len = %Zu", group_name_len)
+        } /* end if */
+        else
+            parent_group_name = local_group_name;
+
         /* Get parent group name */
-        if(loc.path->user_path_r != NULL && loc.path->obj_hidden == 0)
-            /* Use user_path_r if possible */
-            parent_group_name = H5RS_get_str(loc.path->user_path_r);
-        else {
-            /* Otherwise use H5G_get_name */
-            ssize_t group_name_len; /* Length of parent group name */
-
-            /* Get length of parent group name */
-            if((group_name_len = H5G_get_name(cur_group, NULL, (size_t) 0, lapl_id, H5AC_ind_dxpl_id)) < 0)
-                HGOTO_ERROR(H5E_LINK, H5E_CANTGET, FAIL, "unable to retrieve length of group name")
-
-            /* account for null terminator */
-            group_name_len++;
-
-            /* Copy parent group name */
-            if(NULL == (temp_group_name = (char *)H5MM_malloc((size_t)group_name_len)))
-                HGOTO_ERROR(H5E_LINK, H5E_NOSPACE, FAIL, "memory allocation failed")
-            if(H5G_get_name(cur_group, temp_group_name, (size_t) group_name_len, lapl_id, H5AC_ind_dxpl_id) < 0)
-                HGOTO_ERROR(H5E_LINK, H5E_CANTGET, FAIL, "unable to retrieve group name")
-            parent_group_name = temp_group_name;
-        } /* end else */
+        if(H5G_get_name(&loc, parent_group_name, (size_t) group_name_len, NULL, lapl_id, H5AC_ind_dxpl_id) < 0)
+            HGOTO_ERROR(H5E_LINK, H5E_CANTGET, FAIL, "unable to retrieve group name")
 
         /* Make callback */
         if((cb_info.func)(parent_file_name, parent_group_name, file_name, obj_name, &intent, fapl_id, cb_info.user_data) < 0)
             HGOTO_ERROR(H5E_LINK, H5E_CALLBACK, FAIL, "traversal operator failed")
 
-        /* Free temp_group_name */
-        temp_group_name = (char *)H5MM_xfree(temp_group_name);
-
         /* Check access flags */
         if((intent & H5F_ACC_TRUNC) || (intent & H5F_ACC_EXCL))
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid file open flags")
@@ -460,8 +457,9 @@ done:
         HDONE_ERROR(H5E_ATOM, H5E_CANTRELEASE, FAIL, "unable to close atom for file access property list")
     if(ext_file && H5F_try_close(ext_file) < 0)
         HDONE_ERROR(H5E_LINK, H5E_CANTCLOSEFILE, FAIL, "problem closing external file")
+    if(parent_group_name && parent_group_name != local_group_name)
+        parent_group_name = (char *)H5MM_xfree(parent_group_name);
     full_name = (char *)H5MM_xfree(full_name);
-    temp_group_name = (char *)H5MM_xfree(temp_group_name);
     temp_file_name = (char *)H5MM_xfree(temp_file_name);
     actual_file_name = (char *)H5MM_xfree(actual_file_name);
 
diff --git a/src/Makefile.am b/src/Makefile.am
index 65e2bac..dc0edb3 100755
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -72,7 +72,7 @@ libhdf5_la_SOURCES= H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5HFspace.c H5HFstat.c H5HFtest.c H5HFtiny.c \
         H5HG.c H5HGcache.c H5HGdbg.c \
         H5HL.c H5HLcache.c H5HLdbg.c H5HLint.c \
-        H5HP.c H5I.c H5L.c H5Lexternal.c H5lib_settings.c \
+        H5HP.c H5I.c H5Itest.c H5L.c H5Lexternal.c H5lib_settings.c \
         H5MF.c H5MFaggr.c H5MFdbg.c H5MFsection.c \
         H5MM.c H5MP.c H5MPtest.c \
         H5O.c H5Oainfo.c H5Oalloc.c H5Oattr.c \
diff --git a/src/Makefile.in b/src/Makefile.in
index 88d8793..c7fb1b4 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -122,7 +122,7 @@ am_libhdf5_la_OBJECTS = H5.lo H5checksum.lo H5dbg.lo H5system.lo \
 	H5HFdtable.lo H5HFhdr.lo H5HFhuge.lo H5HFiblock.lo H5HFiter.lo \
 	H5HFman.lo H5HFsection.lo H5HFspace.lo H5HFstat.lo H5HFtest.lo \
 	H5HFtiny.lo H5HG.lo H5HGcache.lo H5HGdbg.lo H5HL.lo \
-	H5HLcache.lo H5HLdbg.lo H5HLint.lo H5HP.lo H5I.lo H5L.lo \
+	H5HLcache.lo H5HLdbg.lo H5HLint.lo H5HP.lo H5I.lo H5Itest.lo H5L.lo \
 	H5Lexternal.lo H5lib_settings.lo H5MF.lo H5MFaggr.lo \
 	H5MFdbg.lo H5MFsection.lo H5MM.lo H5MP.lo H5MPtest.lo H5O.lo \
 	H5Oainfo.lo H5Oalloc.lo H5Oattr.lo H5Oattribute.lo H5Obogus.lo \
@@ -492,7 +492,7 @@ libhdf5_la_SOURCES = H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5HFspace.c H5HFstat.c H5HFtest.c H5HFtiny.c \
         H5HG.c H5HGcache.c H5HGdbg.c \
         H5HL.c H5HLcache.c H5HLdbg.c H5HLint.c \
-        H5HP.c H5I.c H5L.c H5Lexternal.c H5lib_settings.c \
+        H5HP.c H5I.c H5Itest.c H5L.c H5Lexternal.c H5lib_settings.c \
         H5MF.c H5MFaggr.c H5MFdbg.c H5MFsection.c \
         H5MM.c H5MP.c H5MPtest.c \
         H5O.c H5Oainfo.c H5Oalloc.c H5Oattr.c \
@@ -803,6 +803,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5HLint.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5HP.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5I.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Itest.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5L.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Lexternal.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5MF.Plo@am__quote@