[svn-r20513] Description:

Correct several problems with compound datatypes that don't have any
fields added:

- Change assertion to error report when a file is encountered which has this
	situation.

- Added check to attribute creation to avoid creating attributes with a
	datatype like this (datasets and named datatypes already have the check)

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

test/gen_bad_compound.c

@@ -0,0 +1,86 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * 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@hdfgroup.org>
+ *              April 14, 2011
+ *
+ * Purpose:     This program is run to generate an HDF5 data file with objects
+ *              that use compound datatypes with no fields (now forbidden to
+ *              be created by the library, as of v1.4.x).  It must be built/run
+ *              with a copy of the 1.2.x library.
+ */
+
+#include <assert.h>
+#include "hdf5.h"
+
+#define FILENAME "bad_compound.h5"
+
+int main()
+{
+    hid_t       file;
+    hid_t       cmpd_dt;
+    hid_t       sid;
+    hid_t       did;
+    hid_t       aid;
+    hid_t       gid;
+    hsize_t     dim = 1;
+    herr_t      ret;
+
+    /* Create compound datatype, but don't insert fields */
+    cmpd_dt = H5Tcreate(H5T_COMPOUND, (size_t)8);
+    assert(cmpd_dt > 0);
+
+    /* Create File */
+    file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    assert(file > 0);
+
+    /* Create a dataspace to use */
+    sid = H5Screate_simple(1, &dim, NULL);
+    assert(sid > 0);
+
+    /* Create a dataset with the bad compound datatype */
+    did = H5Dcreate(file, "dataset", cmpd_dt, sid, H5P_DEFAULT);
+    assert(did > 0);
+
+    /* Create a group */
+    gid = H5Gcreate(file, "group", (size_t)0);
+    assert(gid > 0);
+
+    /* Create an attribute with the bad compound datatype */
+    aid = H5Acreate(gid, "attr", cmpd_dt, sid, H5P_DEFAULT);
+    assert(aid > 0);
+
+    /* Commit the datatype */ 
+    ret = H5Tcommit(file, "cmpnd", cmpd_dt);
+    assert(ret >= 0);
+
+    /* Close IDs */
+    ret = H5Gclose(gid);
+    assert(ret >= 0);
+    ret = H5Aclose(aid);
+    assert(ret >= 0);
+    ret = H5Sclose(sid);
+    assert(ret >= 0);
+    ret = H5Dclose(did);
+    assert(ret >= 0);
+    ret = H5Tclose(cmpd_dt);
+    assert(ret >= 0);
+    ret = H5Fclose(file);
+    assert(ret >= 0);
+
+    return(0);
+}
+