IDL bugs with HDF routines

[Mark Rivers <RIVERS@cars3.uchicago.edu>]

    Folks,

A couple of people have asked me to post a summary of the bugs in IDL 4.0.1
relating to HDF files.  I have informed RSI of these problems and expect them
to be fixed in the next release.  I have more detailed descriptions and
examples of each bug if anyone is interested.

                                   Mark

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1) Routine HDF_VG_ADDTR does not work at all. It always generates an error.

2) Routine HDF_SD_IDTOREF() is not documented.  It is required to be able to 
   use HDF_VG_ADDTR.

3) Routine HDF_SD_GETDATA crashes IDL when reading an SDS whose data type is
   DFNT_CHAR8.  The technical support people at NCSA have stated that
   DFNT_CHAR8 is a valid, but undocumented, data type for an SDS.

4) Routine HDF_SD_ATTRINFO returns corrupted strings when the attribute is of
   type DFNT_CHAR8 (character data).  The returned strings have a trailing NULL
   character which renders them useless in IDL programs.

5) An error occurs under the following conditions:
    - Create a Scientific Data Set with HDF_SD_CREATE, specifying a data type.
    - Write data to that SDS with HDF_SD_ADDDATA, but pass it an array of a
      different data type than that specified in HDF_SD_CREATE.
    - HDF_SD_ADDDATA appears to work, but the error message
            % Temporary variables are still checked out - cleaning up...      
      occurs when HDF_SD_END is called.