[svn-r7412] Purpose:

    Bug fix

Description:
    H5Gget_objname_by_idx should allow NULL for the 'name' parameter, to allow
for querying for the name's length.

Solution:
    Allow NULL for the 'name' parameter, the internal functions were already
ready to handle that case.

    Clean up RM information about H5Gget_objname_by_idx and
H5Gget_objtype_by_idx also.

Platforms tested:
    FreeBSD 4.8 (sleipnir)
    h5committest

4 files changed, 52 insertions, 41 deletions

diff --git a/doc/html/RM_H5G.html b/doc/html/RM_H5G.html
index ee7b596..34ae2bf 100644
--- a/doc/html/RM_H5G.html
+++ b/doc/html/RM_H5G.html
@@ -857,7 +857,7 @@ create or access function.
 <dl>
 <dt><strong>Name:</strong> <a name="Group-GetObjNameByIdx">H5Gget_objname_by_idx</a>
 <dt><strong>Signature:</strong>
-  <dd><em>ssize_t</em> <code>H5Gget_objname_by_idx</code>(<em>hid_t</em> <code>group_id</code>, 
+  <dd><em>ssize_t</em> <code>H5Gget_objname_by_idx</code>(<em>hid_t</em> <code>loc_id</code>, 
                       <em>hsize_t</em> <code>idx</code>, 
                       <em>char *</em><code>name</code>, 
                       <em>size_t*</em> <code>size</code> )
@@ -865,10 +865,10 @@ create or access function.
   <dd>Returns a name of an object specified by an index.
 <dt><strong>Description:</strong>
   <dd><code>H5Gget_objname_by_idx</code> returns a name of the object 
-      specified by the index <code>idx</code> in the group <code>group_id</code>.
+      specified by the index <code>idx</code> in the group <code>loc_id</code>.
       <p>
-      The group is specified by a group identifier <code>group_id</code>. 
-      If preferred, a file identifier may be passed in <code>group_id</code>; 
+      The group is specified by a group identifier <code>loc_id</code>. 
+      If preferred, a file identifier may be passed in <code>loc_id</code>; 
       that file's root group will be assumed. 
       <p>
       <code>idx</code> is the transient index used to iterate through 
@@ -886,12 +886,13 @@ create or access function.
       the object name is truncated to <code>max_size - 1</code> characters.
       <p>
       Note that if the size of the object's name is unkown, a 
-      preliminary call to <code>H5Gget_objname_by_idx</code> will return
-      that value.  A second call to <code>H5Gget_objname_by_idx</code> 
+      preliminary call to <code>H5Gget_objname_by_idx</code> with <code>name</code>
+      set to NULL will return the length of the object's name.
+      A second call to <code>H5Gget_objname_by_idx</code> 
       can then be used to retrieve the actual name.
 <dt><strong>Parameters:</strong>
   <dl>
-    <dt><em>hid_t</em> <code>group_id</code>
+    <dt><em>hid_t</em> <code>loc_id</code>
         <dd>IN: Group or file identifier.
     <dt><em>hsize_t</em> <code>idx</code>
         <dd>IN: Transient index identifying object.
@@ -902,8 +903,7 @@ create or access function.
   </dl>
 <dt><strong>Returns:</strong>
   <dd>Returns the size of the object name if successful, 
-      or <code>0</code> if no name is associated with the group identifier.
-      Otherwise returns a negative value.
+      otherwise returns a negative value.
 </dl>
 
 
@@ -911,16 +911,16 @@ create or access function.
 <dl>
 <dt><strong>Name:</strong> <a name="Group-GetObjTypeByIdx">H5Gget_objtype_by_idx</a>
 <dt><strong>Signature:</strong>
-  <dd><em>int</em> <code>H5Gget_objtype_by_idx</code>(<em>hid_t</em> <code>group_id</code>, 
+  <dd><em>int</em> <code>H5Gget_objtype_by_idx</code>(<em>hid_t</em> <code>loc_id</code>, 
                       <em>hsize_t</em> <code>idx</code> )
 <dt><strong>Purpose:</strong>
   <dd>Returns the type of an object specified by an index.
 <dt><strong>Description:</strong>
   <dd><code>H5Gget_objtype_by_idx</code> returns the type of the object 
-      specified by the index <code>idx</code> in the group <code>group_id</code>.
+      specified by the index <code>idx</code> in the group <code>loc_id</code>.
       <p>
-      The group is specified by a group identifier <code>group_id</code>. 
-      If preferred, a file identifier may be passed in <code>group_id</code>; 
+      The group is specified by a group identifier <code>loc_id</code>. 
+      If preferred, a file identifier may be passed in <code>loc_id</code>; 
       that file's root group will be assumed. 
       <p>
       <code>idx</code> is the transient index used to iterate through 
@@ -978,7 +978,7 @@ create or access function.
 
 <dt><strong>Parameters:</strong>
   <dl>
-    <dt><em>hid_t</em> <code>group_id</code>
+    <dt><em>hid_t</em> <code>loc_id</code>
         <dd>IN: Group or file identifier.
     <dt><em>hsize_t</em> <code>idx</code>
         <dd>IN: Transient index identifying object.
diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index 2d9b586..524184c 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -74,6 +74,9 @@ Bug Fixes since HDF5-1.6.0 release
 
     Library
     -------
+        - Corrected bug in H5Gget_objname_by_idx which was not allowing NULL
+            for the name when just querying for the object name's length.
+            QAK - 2003/08/25
         - Corrected bug in variable-length string handling which could
             generate a core dump on writing variable-length strings as part
             of a compound datatype on certain architectures.  QAK - 2003/08/25
diff --git a/src/H5G.c b/src/H5G.c
index 896b9bc..cf38421 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -520,8 +520,6 @@ H5Gget_objname_by_idx(hid_t loc_id, hsize_t idx, char *name, size_t size)
 	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a location ID");
     if(H5G_get_type(loc,H5AC_ind_dxpl_id)!=H5G_GROUP)
 	HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a group");
-    if (!name)   
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "nil pointer for name");
         
     if (H5G_get_num_objs(loc, &num_objs, H5AC_ind_dxpl_id)<0)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "unable to retrieve number of members");
@@ -2634,12 +2632,15 @@ H5G_get_objname_by_idx(H5G_entry_t *loc, hsize_t idx, char* name, size_t size, h
               H5G_node_name, loc->cache.stab.btree_addr, &udata))<0)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "iteration operator failed");
     
+    /* Get the length of the name */
     ret_value = (ssize_t)HDstrlen(udata.name);
-    if(name && size>0) {
-        HDstrncpy(name, udata.name, MIN((size_t)(ret_value+1),size-1));
+
+    /* Copy the name into the user's buffer, if given */
+    if(name) {
+        HDstrncpy(name, udata.name, MIN((size_t)(ret_value+1),size));
         if((size_t)ret_value >= size)
             name[size-1]='\0';
-    }
+    } /* end if */
 
 done:
     /* Free the duplicated name */
diff --git a/test/titerate.c b/test/titerate.c
index ee926ea..1624196 100644
--- a/test/titerate.c
+++ b/test/titerate.c
@@ -118,7 +118,7 @@ static void test_iter_group(void)
     int idx;                /* Index in the group */
     char name[NAMELEN];     /* temporary name buffer */
     char *dnames[NDATASETS];/* Names of the datasets created */
-    char dataset_name[16];  /* dataset name */
+    char dataset_name[NAMELEN];  /* dataset name */
     iter_info info;         /* Custom iteration information */
     hsize_t num_membs;      /* Number of group members */
     herr_t ret;		    /* Generic return value */
@@ -199,17 +199,17 @@ static void test_iter_group(void)
         for(i=0; i< (int)num_membs; i++) {
             H5G_obj_t obj_type;         /* Type of object in file */
 
-            ret = H5Gget_objname_by_idx(root_group, (hsize_t)i, dataset_name, 32);
-            CHECK(ret, FAIL, "H5Gget_objsname_by_idx");
+            ret = H5Gget_objname_by_idx(root_group, (hsize_t)i, dataset_name, NAMELEN);
+            CHECK(ret, FAIL, "H5Gget_objname_by_idx");
             
             obj_type = H5Gget_objtype_by_idx(root_group, (hsize_t)i);
-            CHECK(obj_type, H5G_UNKNOWN, "H5Gget_objsname_by_idx");
+            CHECK(obj_type, H5G_UNKNOWN, "H5Gget_objtype_by_idx");
         }
     
         H5E_BEGIN_TRY {
-            ret = (herr_t)H5Gget_objname_by_idx(root_group, (hsize_t)(NDATASETS+3), dataset_name, 16);
+            ret = (herr_t)H5Gget_objname_by_idx(root_group, (hsize_t)(NDATASETS+3), dataset_name, NAMELEN);
         } H5E_END_TRY;   
-        VERIFY(ret, FAIL, "H5Gget_objsname_by_idx");
+        VERIFY(ret, FAIL, "H5Gget_objname_by_idx");
 
         ret = H5Gclose(root_group);
         CHECK(ret, FAIL, "H5Gclose");
@@ -227,17 +227,17 @@ static void test_iter_group(void)
         for(i=0; i< (int)num_membs; i++) {
             H5G_obj_t obj_type;         /* Type of object in file */
 
-            ret = H5Gget_objname_by_idx(file, (hsize_t)i, dataset_name, 32);
-            CHECK(ret, FAIL, "H5Gget_objsname_by_idx");
+            ret = H5Gget_objname_by_idx(file, (hsize_t)i, dataset_name, NAMELEN);
+            CHECK(ret, FAIL, "H5Gget_objname_by_idx");
             
             obj_type = H5Gget_objtype_by_idx(file, (hsize_t)i);
-            CHECK(obj_type, H5G_UNKNOWN, "H5Gget_objsname_by_idx");
+            CHECK(obj_type, H5G_UNKNOWN, "H5Gget_objtype_by_idx");
         }
     
         H5E_BEGIN_TRY {
-            ret = (herr_t)H5Gget_objname_by_idx(file, (hsize_t)(NDATASETS+3), dataset_name, 16);
+            ret = (herr_t)H5Gget_objname_by_idx(file, (hsize_t)(NDATASETS+3), dataset_name, NAMELEN);
         } H5E_END_TRY;   
-        VERIFY(ret, FAIL, "H5Gget_objsname_by_idx");
+        VERIFY(ret, FAIL, "H5Gget_objname_by_idx");
     }
 
     /* Test invalid indices for starting iteration */
@@ -730,7 +730,8 @@ static void test_grp_memb_funcs(void)
     char name[NAMELEN];     /* temporary name buffer */
     char *dnames[NDATASETS+2];/* Names of the datasets created */
     char *obj_names[NDATASETS+2];/* Names of the objects in group */
-    char dataset_name[16];  /* dataset name */
+    char dataset_name[NAMELEN];  /* dataset name */
+    ssize_t name_len;       /* Length of object's name */
     hsize_t num_membs;      /* Number of group members */
     herr_t ret;		    /* Generic return value */
 
@@ -791,7 +792,6 @@ static void test_grp_memb_funcs(void)
     /* Sort the dataset names */
     qsort(dnames,NDATASETS+2,sizeof(char *),iter_strcmp);
 
-
     /* Iterate through the datasets in the root group in various ways */
     file=H5Fopen(DATAFILE, H5F_ACC_RDONLY, H5P_DEFAULT);
     CHECK(file, FAIL, "H5Fopen");
@@ -809,28 +809,35 @@ static void test_grp_memb_funcs(void)
     for(i=0; i< (int)num_membs; i++) {
         H5G_obj_t obj_type;         /* Type of object in file */
 
-        ret = H5Gget_objname_by_idx(root_group, (hsize_t)i, dataset_name, 32);
-        CHECK(ret, FAIL, "H5Gget_objsname_by_idx");
+        /* Test with NULL for name, to query length */
+        name_len = H5Gget_objname_by_idx(root_group, (hsize_t)i, NULL, NAMELEN);
+        CHECK(name_len, FAIL, "H5Gget_objname_by_idx");
+        
+        ret = H5Gget_objname_by_idx(root_group, (hsize_t)i, dataset_name, NAMELEN);
+        CHECK(ret, FAIL, "H5Gget_objname_by_idx");
+
+        /* Double-check that the length is the same */
+        VERIFY(ret, name_len, "H5Gget_objname_by_idx");
         
         /* Keep a copy of the dataset names around for later */
         obj_names[i]=HDstrdup(dataset_name);
-        CHECK(dnames[i], NULL, "strdup");           
+        CHECK(obj_names[i], NULL, "strdup");
         
         obj_type = H5Gget_objtype_by_idx(root_group, (hsize_t)i);
-        CHECK(obj_type, H5G_UNKNOWN, "H5Gget_objsname_by_idx");
+        CHECK(obj_type, H5G_UNKNOWN, "H5Gget_objtype_by_idx");
 
         if(!HDstrcmp(dataset_name, "grp"))
-            VERIFY(obj_type, H5G_GROUP, "H5Gget_objsname_by_idx");
+            VERIFY(obj_type, H5G_GROUP, "H5Gget_objname_by_idx");
         if(!HDstrcmp(dataset_name, "dtype"))
-            VERIFY(obj_type, H5G_TYPE, "H5Gget_objsname_by_idx");
+            VERIFY(obj_type, H5G_TYPE, "H5Gget_objname_by_idx");
         if(!HDstrncmp(dataset_name, "Dataset", 7))
-            VERIFY(obj_type, H5G_DATASET, "H5Gget_objsname_by_idx");
+            VERIFY(obj_type, H5G_DATASET, "H5Gget_objname_by_idx");
     }
     
     H5E_BEGIN_TRY {
-        ret = (herr_t)H5Gget_objname_by_idx(root_group, (hsize_t)(NDATASETS+3), dataset_name, 16);
+        ret = (herr_t)H5Gget_objname_by_idx(root_group, (hsize_t)(NDATASETS+3), dataset_name, NAMELEN);
     } H5E_END_TRY;   
-    VERIFY(ret, FAIL, "H5Gget_objsname_by_idx");
+    VERIFY(ret, FAIL, "H5Gget_objname_by_idx");
 
     /* Sort the dataset names */
     qsort(obj_names,NDATASETS+2,sizeof(char *),iter_strcmp);