[fitswcs] WCSLIB 7.4 releaed

[Mark Calabretta]

Greetings,

WCSLIB 7.4 is now available:

   ftp://ftp.atnf.csiro.au/pub/software/wcslib/wcslib.tar.bz2

It contains a number of important bug fixes, particularly for wcshdo(),
and enhancements, as per the change log appended below.

Mark Calabretta



WCSLIB version 7.4 (2021/01/31)
-------------------------------

* C library

  - In wcshdo(), fixed a bug introduced in release 5.9 that potentially
    caused loss of numerical precision in the sprintf() formatting of
    floating point keyvalues.  This was triggered when a large range of
    CRPIXja, PCi_ja, or CDELTia values (as three separate groups) were
    formatted using an 'f' format descriptor, the range not being so
    large that it would have forced wcshdo() to revert to 'E' format.
    Reported by Mohammad Akhlaghi.

    Also in wcshdo(), fixed a bug introduced in release 7.1 that caused
    the coefficients of the TPD distortion function not to be written to
    the header.  TPD and Polynomial distortion function headers will now
    always include the DPja.DOCORR keyword.  Reported by Derek Homeier
    with patch.

  - In wcsset(), fixed a segv generated in attempting to report a non-
    standard units string with wcserr message reporting disabled.
    Reported by Mohammad Akhlaghi.

    In wcsutrne(), allow 'Angstroms' and 'angstroms' as additional
    synonyms for 'Angstrom'.

  - In datfix(), ensure that 0 is returned if an informational message
    is set in wcsprm::err.  Consequent on feedback independently from
    Mihai Cara and Bruce Merry.

    Clarified that informational messages may be set in wcsprm::err
    for returns of 0 from datfix(), obsfix(), unitfix(), and spcfix().

* User manual

  - Added cautions about translating CDi_ja to PCi_ja plus CDELTia for
    those historical distortion functions (TPV, TNX, ZPX) that expect to
    operate on intermediate world coordinates, rather than intermediate
    pixel coordinates.  Consequent on feedback from Mohammad Akhlaghi.

  - Documentation generation moved to doxygen 1.9.1 (was 1.8.19).