internal libtiff bug in 64bit built

[rouault]

On a 64bit GDAL build with internal libtiff support, GDALChecksumImage on the attached TIF gives 21227.

On a 64bit GDAL build with external libtiff support, GDALChecksumImage on the attached TIF gives 23035.

On a 32bit GDAL build with internal libtiff support, GDALChecksumImage on the attached TIF gives 23035.

Conclusion: there's something wrong with internal libtiff in 64bit.

[rouault]

TIF file content extracted from frmt24.cit from autotest

[rouault]

Issue solved !

I've diff'd old tif_fax3.c and tif_fax3.c and there's this little interesting change : #ifdef SIZEOF_LONG == 8 --> #if SIZEOF_UNSIGNED_LONG == 8

and we don't test sizeof(unsigned long) in configure.in ....

[rouault]

Fix commited in r12122.

configure needs to be regenerated.

[rouault]

I'm wondering if it wouldn't be good to add something like the following lines in libtiff4 :

#ifndef SIZEOF_UNSIGNED_LONG #error "SIZEOF_UNSIGNED_LONG needs to be defined !" #endif

[warmerdam]

I have modified cpl_config.h.vc to also define this (as 4).

I have also sent an email to the libtiff list discussing options to make tif_fax3.c less fragile.

Thanks Even!