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December 2007

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2007.12.30 22:20 "libtiff4 - tests failing - TIFF_SETGET_UNDEFINED for some tags", by Frank Warmerdam
2007.12.30 23:07 "Re: libtiff4 - tests failing - TIFF_SETGET_UNDEFINED for some tags", by Frank Warmerdam
2007.12.30 23:59 "Re: libtiff4 - tests failing - TIFF_SETGET_UNDEFINED for some tags", by Bob Friesenhahn
2007.12.31 17:03 "Re: libtiff4 - 64-bit problems", by Edward Lam

2007.12.30 22:20 "libtiff4 - tests failing - TIFF_SETGET_UNDEFINED for some tags", by Frank Warmerdam

Folks,

I am looking to add some capabilities in libtiff4 (aka CVS head) and I
discovered the libtiff/test directory as a nice place to add some tests.
However, I discovered that the existing tests do not actually pass.

I investigated, and it seems some tags can't be read (such as
TIFFTAG_PIXAR_TEXTUREFORMAT) because even though they have a type of
TIFF_ASCII, the set_field_type is TIFF_SETGET_UNDEFINED and this seems to
result in the value not being processed.

I find setting the set_field_type to TIFF_SETGET_ASCII seems to resolve
the problem and the test passes.  But it is not at all clear to me how this
is all supposed to work.  Is there a reason so many tags defined in
tif_dirinfo.c have the set_field_type and the get_field_type fields set to
TIFF_SETGET_UNDEFINED?  Is there a reason that having the get_field_type
field as TIFF_SETGET_UNDEFINED seems to be fine (the field can be written
to disk)?  Is there some more detailed documentation of how the
_TIFFFieldArray structure contents work than the brief blurbs in the
structure definition itself?

I'm feeling lost!  I've held my changes to tif_dirinfo.c till I get some
sort of answer on what I should be doing in the hopes of pursuing a more
comprehensive solution.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam@pobox.com
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