[svn-r410] Changes since 19980604

----------------------

./src/H5A.c
	Named data types can have attributes.

	Fixed bugs where the API functions didn't check the return
	values of their internal counterparts and thus the automatic
	error reporting didn't work.

	Fixed some places where the error stack wasn't cleared after a
	function returned failure.

	Data types returned by H5Aget_type() are always read-only.

	If the `attr_num' argument of H5Aiterate() is null then it
	acts like H5Giterate() instead of failing -- it begins
	processing attributes with the first one.

./src/H5D.c
	We check for allocation overruns when scalar datasets are
	stored in external files.

./src/H5O.c
	H5O_modify() will fail if the message is >=16kB.

./src/H5Oattr.c
	Split some long lines

./src/H5T.c
./src/H5Tprivate.h
	Added H5T_entof() to support attributes on named types.

./src/h5ls.c
	Prints the names of attributes and their sizes.

./test/cmpd_dset.c
./test/dsets.c
./test/dtypes.c
./test/extend.c
./test/external.c
./test/gheap.c
./test/istore.c
./test/links.c
./test/shtype.c
	If the environment variable HDF5_NOCLEANUP is defined then the
	temporary files are not removed.  The testhdf5 program still
	has the bug that it removes *.h5, clobbering test files from
	other programs... oh well.

./test/dtypes.c
	Added attribute tests.

1 files changed, 302 insertions, 198 deletions

diff --git a/src/H5A.c b/src/H5A.c
index fbce35e..efe8b2d 100644
--- a/src/H5A.c
+++ b/src/H5A.c
@@ -1,13 +1,13 @@
 /****************************************************************************
-* NCSA HDF								                                    *
-* Software Development Group						                        *
-* National Center for Supercomputing Applications			                *
-* University of Illinois at Urbana-Champaign				                *
-* 605 E. Springfield, Champaign IL 61820				                    *
-*									                                        *
-* For conditions of distribution and use, see the accompanying		        *
-* hdf/COPYING file.							                                *
-*									                                        *
+* NCSA HDF								    *
+* Software Development Group						    *
+* National Center for Supercomputing Applications			    *
+* University of Illinois at Urbana-Champaign				    *
+* 605 E. Springfield, Champaign IL 61820				    *
+*									    *
+* For conditions of distribution and use, see the accompanying		    *
+* hdf/COPYING file.							    *
+*									    *
 ****************************************************************************/
 
 #ifdef RCSID
@@ -16,31 +16,32 @@ static char		RcsId[] = "$Revision$";
 
 /* $Id$ */
 
-#define H5A_PACKAGE		/*suppress error about including H5Apkg	  */
+#define H5A_PACKAGE		/*suppress error about including H5Apkg	*/
 
 /* Private header files */
 #include <H5private.h>		/* Generic Functions			*/
-#include <H5Iprivate.h>		/* IDs			  	*/
+#include <H5Iprivate.h>		/* IDs			  		*/
 #include <H5Bprivate.h>		/* B-tree subclass names	  	*/
-#include <H5Dprivate.h>		    /* Datasets				*/
-#include <H5Gprivate.h>		    /* Groups				*/
-#include <H5Tprivate.h>		    /* Datatypes				*/
+#include <H5Dprivate.h>		/* Datasets				*/
+#include <H5Gprivate.h>		/* Groups				*/
+#include <H5Tprivate.h>		/* Datatypes				*/
 #include <H5Eprivate.h>		/* Error handling		  	*/
 #include <H5MMprivate.h>	/* Memory management			*/
 #include <H5Pprivate.h>		/* Property lists			*/
-#include <H5Oprivate.h>     /* Object Headers       */
-#include <H5Apkg.h>		    /* Attributes		*/
+#include <H5Oprivate.h>     	/* Object Headers       		*/
+#include <H5Apkg.h>		/* Attributes				*/
 
 #define PABLO_MASK	H5A_mask
 
 /* Is the interface initialized? */
 static hbool_t		interface_initialize_g = FALSE;
-#define INTERFACE_INIT H5A_init_interface
+#define INTERFACE_INIT	H5A_init_interface
 static herr_t		H5A_init_interface(void);
 
 /* PRIVATE PROTOTYPES */
-static void		H5A_term_interface(void);
-static hid_t H5A_create(const H5G_entry_t *ent, const char *name, const H5T_t *type, const H5S_t *space);
+static void H5A_term_interface(void);
+static hid_t H5A_create(const H5G_entry_t *ent, const char *name,
+			const H5T_t *type, const H5S_t *space);
 static hid_t H5A_open(H5G_entry_t *ent, unsigned idx);
 static herr_t H5A_write(H5A_t *attr, const H5T_t *mem_type, void *buf);
 static herr_t H5A_read(H5A_t *attr, const H5T_t *mem_type, void *buf);
@@ -142,23 +143,45 @@ H5A_term_interface(void)
     attribute is reduced to zero.
         The location object may be either a group or a dataset, both of
     which may have any sort of attribute.
+ *
+ * Modifications:
+ * 	Robb Matzke, 5 Jun 1998
+ *	The LOC_ID can also be a committed data type.
+ *	
 --------------------------------------------------------------------------*/
 hid_t
 H5Acreate(hid_t loc_id, const char *name, hid_t datatype, hid_t dataspace,
     hid_t create_plist)
 {
-    void           *obj = NULL;
-    H5G_entry_t    *ent = NULL;
-    H5T_t		   *type = NULL;
-    H5S_t		   *space = NULL;
-    const H5D_create_t	   *create_parms = NULL;
-    hid_t		    ret_value = FAIL;
+    void           	*obj = NULL;
+    H5G_entry_t    	*ent = NULL;
+    H5T_t		*type = NULL;
+    H5S_t		*space = NULL;
+    const H5D_create_t	*create_parms = NULL;
+    hid_t		ret_value = FAIL;
 
     FUNC_ENTER(H5Acreate, FAIL);
 
     /* check arguments */
-    if (!(H5_DATASET == H5I_group(loc_id) || H5_GROUP == H5I_group(loc_id))) {
-        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "attribute target not a dataset or group");
+    if (NULL==(obj=H5I_object (loc_id))) {
+	HRETURN_ERROR (H5E_ARGS, H5E_BADATOM, FAIL, "illegal object atom");
+    }
+    switch (H5I_group (loc_id)) {
+    case H5_DATASET:
+	ent = H5D_entof ((H5D_t*)obj);
+	break;
+    case H5_DATATYPE:
+	if (NULL==(ent=H5T_entof ((H5T_t*)obj))) {
+	    HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+			   "target data type is not committed");
+	}
+	break;
+    case H5_GROUP:
+	ent = H5G_entof ((H5G_t*)obj);
+	break;
+    default:
+	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+		       "inappropriate attribute target");
     }
     if (!name || !*name) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name");
@@ -171,7 +194,7 @@ H5Acreate(hid_t loc_id, const char *name, hid_t datatype, hid_t dataspace,
 	NULL == (space = H5I_object(dataspace))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space");
     }
-    if (create_plist >= 0) {
+    if (H5P_DEFAULT!=create_plist) {
 	if (H5P_DATASET_CREATE != H5Pget_class(create_plist) ||
 	    NULL == (create_parms = H5I_object(create_plist))) {
 	    HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
@@ -181,16 +204,11 @@ H5Acreate(hid_t loc_id, const char *name, hid_t datatype, hid_t dataspace,
 	create_parms = &H5D_create_dflt;
     }
 
-    /* Get the dataset or group's pointer */
-    if(NULL == (obj = H5I_object(loc_id)))
-        HRETURN_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "illegal object atom");
-    if (H5_DATASET == H5I_group(loc_id))
-	ent = H5D_entof ((H5D_t*)obj);
-    else
-	ent = H5G_entof ((H5G_t*)obj);
-
     /* Go do the real work for attaching the attribute to the dataset */
-    ret_value=H5A_create(ent,name,type,space);
+    if ((ret_value=H5A_create(ent,name,type,space))<0) {
+	HRETURN_ERROR (H5E_ATTR, H5E_CANTINIT, FAIL,
+		       "unable to create attribute");
+    }
 
     FUNC_LEAVE(ret_value);
 } /* H5Acreate() */
@@ -217,7 +235,8 @@ H5Acreate(hid_t loc_id, const char *name, hid_t datatype, hid_t dataspace,
  *-------------------------------------------------------------------------
  */
 static hid_t
-H5A_create(const H5G_entry_t *ent, const char *name, const H5T_t *type, const H5S_t *space)
+H5A_create(const H5G_entry_t *ent, const char *name, const H5T_t *type,
+	   const H5S_t *space)
 {
     H5A_t       *attr = NULL;
     H5A_t       found_attr;
@@ -269,12 +288,13 @@ H5A_create(const H5G_entry_t *ent, const char *name, const H5T_t *type, const H5
 	}
 	H5O_reset (H5O_ATTR, &found_attr);
 	seq++;
-    } /* end while */
+    }
+    H5E_clear ();
 
     /* Create the attribute message and save the attribute index */
     if (H5O_modify(&(attr->ent), H5O_ATTR, H5O_NEW_MESG, 0, attr) < 0) 
         HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL,
-            "can't update attribute header messages");
+		    "unable to update attribute header messages");
 
     /* Register the new attribute and get an ID for it */
     if ((ret_value = H5I_register(H5_ATTR, attr)) < 0) {
@@ -340,7 +360,8 @@ H5A_get_index(H5G_entry_t *ent, const char *name)
 	}
 	H5O_reset (H5O_ATTR, &found_attr);
 	i++;
-    } /* end while */
+    }
+    H5E_clear ();
     
     if(ret_value<0) {
         HRETURN_ERROR(H5E_ATTR, H5E_NOTFOUND, FAIL,
@@ -372,42 +393,56 @@ H5A_get_index(H5G_entry_t *ent, const char *name)
     H5Aclose or resource leaks will develop.
         The location object may be either a group or a dataset, both of
     which may have any sort of attribute.
+ *
+ * Modifications:
+ * 	Robb Matzke, 5 Jun 1998
+ *	The LOC_ID can also be a named (committed) data type.
 --------------------------------------------------------------------------*/
 hid_t
 H5Aopen_name(hid_t loc_id, const char *name)
 {
-    H5G_entry_t    *ent = NULL;     /* Symbol table entry of object to attribute */
-    void           *obj = NULL;
-    intn            idx=0;
-    hid_t		    ret_value = FAIL;
+    H5G_entry_t    	*ent = NULL;   /*Symtab entry of object to attribute*/
+    void           	*obj = NULL;
+    intn            	idx=0;
+    hid_t		ret_value = FAIL;
 
     FUNC_ENTER(H5Aopen_name, FAIL);
 
     /* check arguments */
-    if (!(H5_DATASET == H5I_group(loc_id) || H5_GROUP == H5I_group(loc_id))) {
-        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "attribute target not a dataset or group");
+    if(NULL == (obj = H5I_object(loc_id))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "illegal object atom");
+    }
+    switch (H5I_group (loc_id)) {
+    case H5_DATASET:
+	ent = H5D_entof ((H5D_t*)obj);
+	break;
+    case H5_DATATYPE:
+	if (NULL==(ent=H5T_entof ((H5T_t*)obj))) {
+	    HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+			   "target data type is not committed");
+	}
+	break;
+    case H5_GROUP:
+	ent = H5G_entof ((H5G_t*)obj);
+	break;
+    default:
+	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+		       "inappropriate attribute target");
     }
     if (!name || !*name) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name");
     }
 
-    /* Get the dataset or group's pointer */
-    if(NULL == (obj = H5I_object(loc_id)))
-        HRETURN_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "illegal object atom");
-
-    /* Copy the object header entry for the object */
-    if (H5_DATASET == H5I_group(loc_id))
-	ent = H5D_entof ((H5D_t*)obj);
-    else
-	ent = H5G_entof ((H5G_t*)obj);
-
     /* Look up the attribute for the object */
     if((idx=H5A_get_index(ent,name))<0)
         HRETURN_ERROR(H5E_ATTR, H5E_BADVALUE, FAIL, "attribute not found");
 
     /* Go do the real work for opening the attribute */
-    ret_value=H5A_open(ent, (unsigned)idx);
-
+    if ((ret_value=H5A_open(ent, (unsigned)idx))<0) {
+	HRETURN_ERROR (H5E_ATTR, H5E_CANTINIT, FAIL,
+		       "unable to open attribute");
+    }
+    
     FUNC_LEAVE(ret_value);
 } /* H5Aopen_name() */
 
@@ -433,34 +468,49 @@ H5Aopen_name(hid_t loc_id, const char *name)
     H5Aclose or resource leaks will develop.
         The location object may be either a group or a dataset, both of
     which may have any sort of attribute.
+ *
+ * Modifications:
+ * 	Robb Matzke, 5 Jun 1998
+ *	The LOC_ID can also be a named (committed) data type.
+ *	
 --------------------------------------------------------------------------*/
 hid_t
 H5Aopen_idx(hid_t loc_id, unsigned idx)
 {
-    H5G_entry_t    *ent = NULL;     /* Symbol table entry of object to attribute */
-    void           *obj = NULL;
-    hid_t		    ret_value = FAIL;
+    H5G_entry_t	*ent = NULL;	/*Symtab entry of object to attribute */
+    void        *obj = NULL;
+    hid_t	ret_value = FAIL;
 
     FUNC_ENTER(H5Aopen_idx, FAIL);
 
     /* check arguments */
-    if (!(H5_DATASET == H5I_group(loc_id) || H5_GROUP == H5I_group(loc_id))) {
-        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "attribute target not a dataset or group");
-    }
-
-    /* Get the dataset or group's pointer */
-    if(NULL == (obj = H5I_object(loc_id)))
+    if(NULL == (obj = H5I_object(loc_id))) {
         HRETURN_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "illegal object atom");
-
-    /* Copy the object header entry for the object */
-    if (H5_DATASET == H5I_group(loc_id))
+    }
+    switch (H5I_group (loc_id)) {
+    case H5_DATASET:
 	ent = H5D_entof ((H5D_t*)obj);
-    else
+	break;
+    case H5_DATATYPE:
+	if (NULL==(ent=H5T_entof ((H5T_t*)obj))) {
+	    HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+			   "target data type is not committed");
+	}
+	break;
+    case H5_GROUP:
 	ent = H5G_entof ((H5G_t*)obj);
+	break;
+    default:
+	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+		       "inappropriate attribute target");
+    }
 
     /* Go do the real work for opening the attribute */
-    ret_value=H5A_open(ent, idx);
-
+    if ((ret_value=H5A_open(ent, idx))<0) {
+	HRETURN_ERROR (H5E_ATTR, H5E_CANTINIT, FAIL,
+		       "unable to open attribute");
+    }
+    
     FUNC_LEAVE(ret_value);
 } /* H5Aopen_idx() */
 
@@ -555,11 +605,11 @@ H5Awrite(hid_t attr_id, hid_t mem_dt, void *buf)
 
     /* check arguments */
     if (H5_ATTR != H5I_group(attr_id) ||
-            (NULL == (attr = H5I_object(attr_id)))) {
+	(NULL == (attr = H5I_object(attr_id)))) {
         HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute");
     }
     if (H5_DATATYPE != H5I_group(mem_dt) ||
-            NULL == (mem_type = H5I_object(mem_dt))) {
+	NULL == (mem_type = H5I_object(mem_dt))) {
         HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data type");
     }
     if (NULL == buf) {
@@ -569,7 +619,7 @@ H5Awrite(hid_t attr_id, hid_t mem_dt, void *buf)
     /* Go write the actual data to the attribute */
     if ((ret_value=H5A_write(attr,mem_type,buf))<0) {
         HRETURN_ERROR(H5E_ATTR, H5E_WRITEERROR, FAIL,
-            "can't write attribute");
+		      "unable to write attribute");
     }
 
     FUNC_LEAVE(ret_value);
@@ -597,16 +647,16 @@ H5Awrite(hid_t attr_id, hid_t mem_dt, void *buf)
 static herr_t
 H5A_write(H5A_t *attr, const H5T_t *mem_type, void *buf)
 {
-    uint8		*tconv_buf = NULL;	/* data type conv buffer	*/
-    size_t		    nelmts;		    /* elements in attribute	*/
+    uint8		*tconv_buf = NULL;	/* data type conv buffer */
+    size_t		nelmts;		    	/* elements in attribute */
     H5T_conv_t		tconv_func = NULL;	/* conversion function	*/
     H5T_cdata_t		*cdata = NULL;		/* type conversion data	*/
     hid_t		src_id = -1, dst_id = -1;/* temporary type atoms */
     size_t		src_type_size;		/* size of source type	*/
     size_t		dst_type_size;		/* size of destination type*/
-    size_t		buf_size;		    /* desired buffer size	*/
-    int         idx;                /* index of attribute in object header */
-    herr_t		    ret_value = FAIL;
+    size_t		buf_size;		/* desired buffer size	*/
+    int         	idx;	      /* index of attribute in object header */
+    herr_t		ret_value = FAIL;
 #ifdef H5T_DEBUG
     H5_timer_t		timer;
 #endif
@@ -626,12 +676,12 @@ H5A_write(H5A_t *attr, const H5T_t *mem_type, void *buf)
 
     /* Get the maximum buffer size needed and allocate it */
     buf_size = nelmts*MAX(src_type_size,dst_type_size);
-	tconv_buf = H5MM_xmalloc (buf_size);
+    tconv_buf = H5MM_xmalloc (buf_size);
 
     /* Copy the user's data into the buffer for conversion */
     HDmemcpy(tconv_buf,buf,src_type_size*nelmts);
 
-/* Convert memory buffer into disk buffer */
+    /* Convert memory buffer into disk buffer */
     /* Set up type conversion function */
     if (NULL == (tconv_func = H5T_find(mem_type, attr->dt,
 				       H5T_BKG_NO, &cdata))) {
@@ -640,22 +690,22 @@ H5A_write(H5A_t *attr, const H5T_t *mem_type, void *buf)
     } else if (H5T_conv_noop!=tconv_func) {
         if ((src_id = H5I_register(H5_DATATYPE,
 				   H5T_copy(mem_type, H5T_COPY_ALL)))<0 ||
-                (dst_id = H5I_register(H5_DATATYPE,
-				       H5T_copy(attr->dt, H5T_COPY_ALL)))<0) {
+	    (dst_id = H5I_register(H5_DATATYPE,
+				   H5T_copy(attr->dt, H5T_COPY_ALL)))<0) {
             HGOTO_ERROR(H5E_ATTR, H5E_CANTREGISTER, FAIL,
 			"unable to register types for conversion");
         }
     }
 
-	/* Perform data type conversion.  */
+    /* Perform data type conversion.  */
 #ifdef H5T_DEBUG
     H5T_timer_begin (&timer, cdata);
 #endif
-	cdata->command = H5T_CONV_CONV;
-	if ((tconv_func) (src_id, dst_id, cdata, nelmts, tconv_buf, NULL)<0) {
-	    HGOTO_ERROR(H5E_ATTR, H5E_CANTENCODE, FAIL,
-			"data type conversion failed");
-	}
+    cdata->command = H5T_CONV_CONV;
+    if ((tconv_func) (src_id, dst_id, cdata, nelmts, tconv_buf, NULL)<0) {
+	HGOTO_ERROR(H5E_ATTR, H5E_CANTENCODE, FAIL,
+		    "data type conversion failed");
+    }
 #ifdef H5T_DEBUG
     H5T_timer_end (&timer, cdata, nelmts);
 #endif
@@ -672,7 +722,7 @@ H5A_write(H5A_t *attr, const H5T_t *mem_type, void *buf)
     attr->data=tconv_buf;   /* Set the data pointer temporarily */
     if (H5O_modify(&(attr->ent), H5O_ATTR, idx, 0, attr) < 0) 
         HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL,
-            "can't update attribute header messages");
+		    "unable to update attribute header messages");
     attr->data=NULL;    /* un-do the data pointer */
 
     /* Indicate the the attribute doesn't need fill-values */
@@ -722,11 +772,11 @@ H5Aread(hid_t attr_id, hid_t mem_dt, void *buf)
 
     /* check arguments */
     if (H5_ATTR != H5I_group(attr_id) ||
-            (NULL == (attr = H5I_object(attr_id)))) {
+	(NULL == (attr = H5I_object(attr_id)))) {
         HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute");
     }
     if (H5_DATATYPE != H5I_group(mem_dt) ||
-            NULL == (mem_type = H5I_object(mem_dt))) {
+	NULL == (mem_type = H5I_object(mem_dt))) {
         HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data type");
     }
     if (NULL == buf) {
@@ -736,7 +786,7 @@ H5Aread(hid_t attr_id, hid_t mem_dt, void *buf)
     /* Go write the actual data to the attribute */
     if ((ret_value=H5A_read(attr,mem_type,buf))<0) {
         HRETURN_ERROR(H5E_ATTR, H5E_READERROR, FAIL,
-            "can't read attribute");
+		      "unable to read attribute");
     }
 
     FUNC_LEAVE(ret_value);
@@ -764,15 +814,15 @@ H5Aread(hid_t attr_id, hid_t mem_dt, void *buf)
 static herr_t
 H5A_read(H5A_t *attr, const H5T_t *mem_type, void *buf)
 {
-    uint8		*tconv_buf = NULL;	/* data type conv buffer	*/
-    size_t		    nelmts;		    /* elements in attribute	*/
-    H5T_conv_t		tconv_func = NULL;	/* conversion function	*/
+    uint8		*tconv_buf = NULL;	/* data type conv buffer*/
+    size_t		nelmts;			/* elements in attribute*/
+    H5T_conv_t		tconv_func = NULL;	/* conversion function 	*/
     H5T_cdata_t		*cdata = NULL;		/* type conversion data	*/
-    hid_t		src_id = -1, dst_id = -1;/* temporary type atoms */
-    size_t		src_type_size;		/* size of source type	*/
-    size_t		dst_type_size;		/* size of destination type*/
-    size_t		buf_size;		    /* desired buffer size	*/
-    herr_t		    ret_value = FAIL;
+    hid_t		src_id = -1, dst_id = -1;/* temporary type atoms*/
+    size_t		src_type_size;		/* size of source type 	*/
+    size_t		dst_type_size;		/* size of destination type */
+    size_t		buf_size;		/* desired buffer size	*/
+    herr_t		ret_value = FAIL;
 #ifdef H5T_DEBUG
     H5_timer_t		timer;
 #endif
@@ -783,7 +833,6 @@ H5A_read(H5A_t *attr, const H5T_t *mem_type, void *buf)
     assert(mem_type);
     assert(buf);
 
-
     /* Create buffer for data to store on disk */
     nelmts=H5S_get_npoints (attr->ds);
 
@@ -793,12 +842,12 @@ H5A_read(H5A_t *attr, const H5T_t *mem_type, void *buf)
 
     /* Get the maximum buffer size needed and allocate it */
     buf_size = nelmts*MAX(src_type_size,dst_type_size);
-	tconv_buf = H5MM_xmalloc (buf_size);
+    tconv_buf = H5MM_xmalloc (buf_size);
 
     /* Copy the attribute data into the buffer for conversion */
     HDmemcpy(tconv_buf,attr->data,src_type_size*nelmts);
 
-/* Convert memory buffer into disk buffer */
+    /* Convert memory buffer into disk buffer */
     /* Set up type conversion function */
     if (NULL == (tconv_func = H5T_find(attr->dt, mem_type,
 				       H5T_BKG_NO, &cdata))) {
@@ -807,22 +856,22 @@ H5A_read(H5A_t *attr, const H5T_t *mem_type, void *buf)
     } else if (H5T_conv_noop!=tconv_func) {
         if ((src_id = H5I_register(H5_DATATYPE,
 				   H5T_copy(attr->dt, H5T_COPY_ALL)))<0 ||
-                (dst_id = H5I_register(H5_DATATYPE,
-				       H5T_copy(mem_type, H5T_COPY_ALL)))<0) {
+	    (dst_id = H5I_register(H5_DATATYPE,
+				   H5T_copy(mem_type, H5T_COPY_ALL)))<0) {
             HGOTO_ERROR(H5E_ATTR, H5E_CANTREGISTER, FAIL,
 			"unable to register types for conversion");
         }
     }
 
-	/* Perform data type conversion.  */
+    /* Perform data type conversion.  */
 #ifdef H5T_DEBUG
     H5T_timer_begin (&timer, cdata);
 #endif
-	cdata->command = H5T_CONV_CONV;
-	if ((tconv_func) (src_id, dst_id, cdata, nelmts, tconv_buf, NULL)<0) {
-	    HGOTO_ERROR(H5E_ATTR, H5E_CANTENCODE, FAIL,
-			"data type conversion failed");
-	}
+    cdata->command = H5T_CONV_CONV;
+    if ((tconv_func) (src_id, dst_id, cdata, nelmts, tconv_buf, NULL)<0) {
+	HGOTO_ERROR(H5E_ATTR, H5E_CANTENCODE, FAIL,
+		    "data type conversion failed");
+    }
 #ifdef H5T_DEBUG
     H5T_timer_end (&timer, cdata, nelmts);
 #endif
@@ -830,7 +879,6 @@ H5A_read(H5A_t *attr, const H5T_t *mem_type, void *buf)
     /* Copy the converted data into the user's buffer */
     HDmemcpy(buf,tconv_buf,dst_type_size*nelmts);
 
-
     ret_value=SUCCEED;
 
 done:
@@ -867,15 +915,15 @@ done:
 hid_t
 H5Aget_space(hid_t attr_id)
 {
-    H5A_t		   *attr = NULL;
+    H5A_t	*attr = NULL;
     H5S_t	*dst = NULL;
-    hid_t		        ret_value = FAIL;
+    hid_t	ret_value = FAIL;
 
     FUNC_ENTER(H5Aget_space, FAIL);
 
     /* check arguments */
     if (H5_ATTR != H5I_group(attr_id) ||
-            (NULL == (attr = H5I_object(attr_id)))) {
+	(NULL == (attr = H5I_object(attr_id)))) {
         HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute");
     }
 
@@ -916,10 +964,9 @@ H5Aget_space(hid_t attr_id)
  * Modifications:
  * 	Robb Matzke, 4 Jun 1998
  *	The data type is reopened if it's a named type before returning it to
- *	the application.  If the data type of the attribute is read-only then
- *	it is returned to the application as a read-only type. If an error
- *	occurs when atomizing the return data type then the data type is
- *	closed.
+ *	the application.  The data types returned by this function are always
+ *	read-only. If an error occurs when atomizing the return data type
+ *	then the data type is closed.
 --------------------------------------------------------------------------*/
 hid_t
 H5Aget_type(hid_t attr_id)
@@ -932,19 +979,25 @@ H5Aget_type(hid_t attr_id)
 
     /* check arguments */
     if (H5_ATTR != H5I_group(attr_id) ||
-            (NULL == (attr = H5I_object(attr_id)))) {
+	(NULL == (attr = H5I_object(attr_id)))) {
         HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute");
     }
 
     /*
      * Copy the attribute's data type.  If the type is a named type then
-     * reopen the type before returning it to the user.
+     * reopen the type before returning it to the user. Make the type
+     * read-only.
      */
     if (NULL==(dst=H5T_copy (attr->dt, H5T_COPY_REOPEN))) {
 	HRETURN_ERROR (H5E_ATTR, H5E_CANTINIT, FAIL,
 		       "unable to copy datatype");
     }
-
+    if (H5T_lock (dst, FALSE)<0) {
+	H5T_close (dst);
+	HRETURN_ERROR (H5E_DATATYPE, H5E_CANTINIT, FAIL,
+		       "unable to lock transient data type");
+    }
+    
     /* Atomize */
     if ((ret_value=H5I_register (H5_DATATYPE, dst))<0) {
 	H5T_close (dst);
@@ -982,15 +1035,15 @@ H5Aget_type(hid_t attr_id)
 size_t
 H5Aget_name(hid_t attr_id, char *buf, size_t buf_size)
 {
-    H5A_t		   *attr = NULL;
+    H5A_t		*attr = NULL;
     size_t              copy_len=0;
-    size_t		        ret_value = FAIL;
+    size_t		ret_value = FAIL;
 
     FUNC_ENTER(H5Aget_name, FAIL);
 
     /* check arguments */
     if (H5_ATTR != H5I_group(attr_id) ||
-            (NULL == (attr = H5I_object(attr_id)))) {
+	(NULL == (attr = H5I_object(attr_id)))) {
         HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute");
     }
     if (!buf || buf_size==0) {
@@ -1029,30 +1082,41 @@ H5Aget_name(hid_t attr_id, char *buf, size_t buf_size)
  DESCRIPTION
         This function returns the number of attributes attached to a dataset or
     group, 'location_id'.
+ *
+ * Modifications:
+ * 	Robb Matzke, 5 Jun 1998
+ *	The LOC_ID can also be a named (committed) data type.
 --------------------------------------------------------------------------*/
 int
 H5Anum_attrs(hid_t loc_id)
 {
-    H5G_entry_t    *ent = NULL;     /* Symbol table entry of object to attribute */
-    void           *obj = NULL;
-    int		        ret_value = 0;
+    H5G_entry_t    	*ent = NULL;	/*symtab ent of object to attribute */
+    void           	*obj = NULL;
+    int			ret_value = 0;
 
     FUNC_ENTER(H5Anum_attrs, FAIL);
 
     /* check arguments */
-    if (!(H5_DATASET == H5I_group(loc_id) || H5_GROUP == H5I_group(loc_id))) {
-        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "attribute target not a dataset or group");
-    }
-
-    /* Get the dataset or group's pointer */
-    if(NULL == (obj = H5I_object(loc_id)))
+    if(NULL == (obj = H5I_object(loc_id))) {
         HRETURN_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "illegal object atom");
-
-    /* Copy the object header entry for the object */
-    if (H5_DATASET == H5I_group(loc_id))
+    }
+    switch (H5I_group (loc_id)) {
+    case H5_DATASET:
 	ent = H5D_entof ((H5D_t*)obj);
-    else
+	break;
+    case H5_DATATYPE:
+	if (NULL==(ent=H5T_entof ((H5T_t*)obj))) {
+	    HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+			   "target data type is not committed");
+	}
+	break;
+    case H5_GROUP:
 	ent = H5G_entof ((H5G_t*)obj);
+	break;
+    default:
+	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+		       "inappropriate attribute target");
+    }
 
     /* Look up the attribute for the object */
     ret_value=H5O_count(ent, H5O_ATTR);
@@ -1097,51 +1161,74 @@ H5Anum_attrs(hid_t loc_id)
         C. Negative causes the iterator to immediately return that value,
             indicating failure.  The iterator can be restarted at the next
             attribute.
+ *
+ * Modifications:
+ * 	Robb Matzke, 5 Jun 1998
+ *	The LOC_ID can also be a named (committed) data type.
+ *
+ * 	Robb Matzke, 5 Jun 1998
+ *	Like the group iterator, if ATTR_NUM is the null pointer then all
+ *	attributes are processed.
+ *	
 --------------------------------------------------------------------------*/
 int
 H5Aiterate(hid_t loc_id, unsigned *attr_num, H5A_operator_t op, void *op_data)
 {
-    H5G_entry_t    *ent = NULL;     /* Symbol table entry of object to attribute */
-    void           *obj = NULL;
-    H5A_t          found_attr;
-    int		        ret_value = 0;
+    H5G_entry_t		*ent = NULL;	/*symtab ent of object to attribute */
+    void           	*obj = NULL;
+    H5A_t          	found_attr;
+    intn	        ret_value = 0;
+    intn		idx;
 
-    FUNC_ENTER(H5Anum_attrs, FAIL);
+    FUNC_ENTER(H5Aiterate, FAIL);
 
     /* check arguments */
-    if (!(H5_DATASET == H5I_group(loc_id) || H5_GROUP == H5I_group(loc_id))) {
-        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "attribute target not a dataset or group");
+    if(NULL == (obj = H5I_object(loc_id))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "illegal object atom");
     }
-    if (!attr_num) {
-	HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index");
+    switch (H5I_group (loc_id)) {
+    case H5_DATASET:
+	ent = H5D_entof ((H5D_t*)obj);
+	break;
+    case H5_DATATYPE:
+	if (NULL==(ent=H5T_entof ((H5T_t*)obj))) {
+	    HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+			   "target data type is not committed");
+	}
+	break;
+    case H5_GROUP:
+	ent = H5G_entof ((H5G_t*)obj);
+	break;
+    default:
+	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+		       "inappropriate attribute target");
     }
     if (!op) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid operator");
     }
 
-    /* Get the dataset or group's pointer */
-    if(NULL == (obj = H5I_object(loc_id)))
-        HRETURN_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "illegal object atom");
-
-    /* Copy the object header entry for the object */
-    if (H5_DATASET == H5I_group(loc_id))
-	ent = H5D_entof ((H5D_t*)obj);
-    else
-	ent = H5G_entof ((H5G_t*)obj);
 
-    /* Look up the attribute for the object */
-    if((int)*attr_num<H5O_count(ent, H5O_ATTR))   /* Make certain the start point is reasonable */
-        while(H5O_read(ent, H5O_ATTR, *attr_num, &found_attr)!=NULL)
-          {
-              /* Compare found attribute name to new attribute name reject creation if names are the same */
-              (*attr_num)++;
-              if((ret_value=op(loc_id,found_attr.name,op_data))!=0) {
-		  H5O_reset (H5O_ATTR, &found_attr);
-                  break;
-	      }
-	      H5O_reset (H5O_ATTR, &found_attr);
-          } /* end while */
+    /*
+     * Look up the attribute for the object. Make certain the start point is
+     * reasonable.
+     */
+    idx = attr_num ? (intn)*attr_num : 0;
+    if(idx<H5O_count(ent, H5O_ATTR)) {
+        while(H5O_read(ent, H5O_ATTR, idx++, &found_attr)!=NULL) {
+	    /*
+	     * Compare found attribute name to new attribute name reject
+	     * creation if names are the same.
+	     */
+	    if((ret_value=(op)(loc_id,found_attr.name,op_data))!=0) {
+		H5O_reset (H5O_ATTR, &found_attr);
+		break;
+	    }
+	    H5O_reset (H5O_ATTR, &found_attr);
+	}
+	H5E_clear ();
+    }
 
+    if (attr_num) *attr_num = (unsigned)idx;
     FUNC_LEAVE(ret_value);
 } /* H5Aiterate() */
 
@@ -1165,36 +1252,48 @@ H5Aiterate(hid_t loc_id, unsigned *attr_num, H5A_operator_t op, void *op_data)
     This function should not be used when attribute IDs are open on 'loc_id'
     as it may cause the internal indexes of the attributes to change and future 
     writes to the open attributes to produce incorrect results.
+ *
+ * Modifications:
+ * 	Robb Matzke, 5 Jun 1998
+ *	The LOC_ID can also be a named (committed) data type.
+ *	
 --------------------------------------------------------------------------*/
 herr_t
 H5Adelete(hid_t loc_id, const char *name)
 {
-    H5A_t          found_attr;
-    H5G_entry_t    *ent = NULL;     /* Symbol table entry of object to attribute */
-    void           *obj = NULL;
-    intn            idx=0, found=-1;
-    herr_t		    ret_value = FAIL;
+    H5A_t       found_attr;
+    H5G_entry_t	*ent = NULL;		/*symtab ent of object to attribute */
+    void        *obj = NULL;
+    intn        idx=0, found=-1;
+    herr_t	ret_value = FAIL;
 
     FUNC_ENTER(H5Aopen_name, FAIL);
 
     /* check arguments */
-    if (!(H5_DATASET == H5I_group(loc_id) || H5_GROUP == H5I_group(loc_id))) {
-        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "attribute target not a dataset or group");
+    if(NULL == (obj = H5I_object(loc_id))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "illegal object atom");
+    }
+    switch (H5I_group (loc_id)) {
+    case H5_DATASET:
+	ent = H5D_entof ((H5D_t*)obj);
+	break;
+    case H5_DATATYPE:
+	if (NULL==(ent=H5T_entof ((H5T_t*)obj))) {
+	    HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+			   "target data type is not committed");
+	}
+	break;
+    case H5_GROUP:
+	ent = H5G_entof ((H5G_t*)obj);
+	break;
+    default:
+	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+		       "inappropriate attribute target");
     }
     if (!name || !*name) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name");
     }
 
-    /* Get the dataset or group's pointer */
-    if(NULL == (obj = H5I_object(loc_id)))
-        HRETURN_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "illegal object atom");
-
-    /* Copy the object header entry for the object */
-    if (H5_DATASET == H5I_group(loc_id))
-	ent = H5D_entof ((H5D_t*)obj);
-    else
-	ent = H5G_entof ((H5G_t*)obj);
-
     /* Look up the attribute for the object */
     idx=0;
     while(H5O_read(ent, H5O_ATTR, idx, &found_attr)!=NULL) {
@@ -1209,17 +1308,18 @@ H5Adelete(hid_t loc_id, const char *name)
 	}
 	H5O_reset (H5O_ATTR, &found_attr);
 	idx++;
-    } /* end while */
+    }
+    H5E_clear ();
     if (found<0) {
-        HRETURN_ERROR(H5E_ATTR, H5E_NOTFOUND, FAIL,
-		      "attribute not found");
+        HRETURN_ERROR(H5E_ATTR, H5E_NOTFOUND, FAIL, "attribute not found");
     }
 
     /* Delete the attribute from the location */
-    if ((ret_value=H5O_remove(ent, H5O_ATTR, found)) < 0) 
+    if ((ret_value=H5O_remove(ent, H5O_ATTR, found)) < 0) {
         HRETURN_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL,
-            "can't delete attribute header message");
-
+		      "unable to delete attribute header message");
+    }
+    
     FUNC_LEAVE(ret_value);
 } /* H5Adelete() */
 
@@ -1301,7 +1401,9 @@ H5A_copy(const H5A_t *old_attr)
         HDmemcpy(new_attr->data,old_attr->data,old_attr->data_size);
     } /* end if */
 
+#ifndef LATER
     /* Copy the share info? */
+#endif
     
     FUNC_LEAVE(new_attr);
 }
@@ -1336,13 +1438,13 @@ H5A_close(H5A_t *attr)
 
         if (NULL == tmp_buf) {
             HRETURN_ERROR(H5E_ATTR, H5E_NOSPACE, FAIL,
-                "can't allocate attribute fill-value");
+			  "unable to allocate attribute fill-value");
         }
 
         /* Go write the fill data to the attribute */
         if (H5A_write(attr,attr->dt,tmp_buf)<0) {
             HRETURN_ERROR(H5E_ATTR, H5E_WRITEERROR, FAIL,
-                "can't write attribute");
+			  "unable to write attribute");
         }
 
         /* Free temporary buffer */
@@ -1363,7 +1465,9 @@ H5A_close(H5A_t *attr)
     if(attr->ent_opened)
         H5O_close(&(attr->ent));
 
-/* Do something with the shared information? */
+#ifndef LATER
+    /* Do something with the shared information? */
+#endif
 
     H5MM_xfree(attr);