Changes in TIFF v4.5.1
======================

.. table:: References
    :widths: auto

    ======================  ==========================================
    Current Version         v4.5.1 (:tag:`v4.5.1`)
    Previous Version        :doc:`v4.5.0 <v4.5.0>`
    Master Download Site    `<https://download.osgeo.org/libtiff/>`_
    Master HTTP Site #1     `<http://www.simplesystems.org/libtiff/>`_
    Master HTTP Site #2     `<https://libtiff.gitlab.io/libtiff/>`_
    Master HTTP Site #3     `<http://libtiff.maptools.org/>`_
    ======================  ==========================================

This document provides a summary of significant changes made to the
software between the *previous* and *current* versions (see
above). A fully-detailed change summary is provided by the :file:`ChangeLog` file
included in the release package and by the Git commit history:

.. warning::

    This version will be the last one supporting most TIFF tools (except tiffinfo,
    tiffdump, tiffcp and tiffset), whose maintenance will be discontinued, due
    to the lack of contributors able to address reported security issues.
    Starting with libtiff v4.6.0, their source code, at this time ,will still be
    available in the source distribution, but they will no longer be built by
    default, and issues related to them will no longer be accepted in the
    libtiff bug tracker.


.. warning::

    Some CMake related changes, in particular related to the CMake config file
    now installed, should be considered as a preview and may change in the next
    releases based on user feedback.
    See discussion in https://gitlab.com/libtiff/libtiff/-/merge_requests/496
    and https://gitlab.com/libtiff/libtiff/-/merge_requests/494

Major changes
-------------

None

Software configuration changes
------------------------------

* Definition of tags reformatted (clang-format off) for better
  readability of tag comments in tiff.h and tif_dirinfo.c

* Do not install libtiff-4.pc when tiff-install is reset.

* Add versioninfo resource files for DLL and tools
  compiled with Windows MSVC and MINGW.

* Disable clang-formatting for tif_config.h.cmake.in and
  tiffconf.h.cmake.in because sensitive for CMake scripts.

* CMake: make WebP component name compatible with upstream ConfigWebP.cmake

* CMake: make Findliblzma with upstream CMake config file

* CMake: FindDeflate.cmake: fix several errors (:issue:`526`).

* CMake: FindLERC.cmake: version string return added.

* CMake: export TiffConfig.cmake and TiffConfigVersion.cmake files

* CMake: fix export of INTERFACE_INCLUDE_DIRECTORIES

Library changes
---------------

New/improved functionalities:

* Hardcode HOST_FILLORDER to FILLORDER_LSB2MSB and make 'H' flag of
  :c:func:`TIFFOpen` to warn and an alias of FILLORDER_MSB2LSB. 
  :file:`tif_lerc.c`: use WORDS_BIGENDIAN instead of HOST_BIGENDIAN.

* Optimize relative seeking within :c:func:`TIFFSetDirectory`
  by using the learned list of IFD offsets.

* Improve internal IFD offset and directory number map handling.

* Behavior of :c:func:`TIFFOpen`  mode "r+" in the Windows implementation
  adjusted to that of Linux.

API/ABI breaks:

* None

Bug fixes:

* TIFFDirectory td_fieldsset type changed from unsigned long, which can
  be 32 or 64 bits, to uint32_t (fixes :issue:`484`).

* tif_ojpeg.c: checking for division by zero (fixes :issue:`554`).

* LZWDecode(): avoid crash when trying to read again from a strip whith
  a missing end-of-information marker (fixes :issue:`548`).

* Fixed runtime error: applying zero offset to null pointer
  in :c:func:`countInkNamesString`.

* Fixing crash in :c:func:`TIFFUnlinkDirectory` when called with
  directory number zero ("TIFFUnlinkDirectory(**0**)") as well as fixing
  incorrect behaviour when unlinking the first directory.

* tif_luv: check and correct for NaN data in :c:func:`uv_encode`
  (:issue:`530`).

* :c:func:`TIFFClose` avoid NULL pointer dereferencing
  (:issue:`515`).

* tif_hash_set.c: include tif_hash_set.h after tif_config.h
  to let a chance for GDAL symbol renaming trick.

* Fax3: fix failure to decode some fax3 number_of_images
  and add test for Fax3 decoding issues
  (:issue:`513`).

* :c:func:`TIFFSetDirectory` and :c:func:`TIFFWriteDirectorySec` 
  avoid harmless unsigned-integer-overflow
  (due to gdal oss-fuzz #54311 and #54343).

* :file:`tif_ojpeg.c`: fix :issue:`554` by checking for division by zero
  in OJPEGWriteHeaderInfo().

* LZWDecode(): avoid crash when trying to read again from a strip whith
  a missing end-of-information marker (:issue:`548`).

Documentation
-------------

* mention TIFFSetTagExtender() cannot add tags to custom directories.

* manpage: add multi page TIFF and SubIFDs description and read / write example.

Tools changes
-------------

New/improved functionality:

* None

Bug fixes:

* :program:`tiffcrop`: Consider error return of writeSelections() (fixes :issue:`553`).

* :program:`tiffcrop`: fix memory leak
  (:issue:`475`).

* :program:`tiffcrop`: do not reuse input buffer for subsequent images
  (:issue:`527`).

* :program:`tiffcrop`: Amend rotateImage() not to toggle the input
  (main) image width and length parameters when only cropped image
  sections are rotated. Remove buffptr from region structure
  because never used. Fixes
  :issue:`492`, :issue:`493`, :issue:`494`, :issue:`495`,
  :issue:`499`, :issue:`518`, :issue:`519`.

* :program:`tiffcrop`: correctly update buffersize after rotateImage() 
  (:issue:`520`).

* :program:`tiffcrop`: added check for assumption on composite images. Fixes
  :issue:`496`, :issue:`497`, :issue:`498`, :issue:`500`, :issue:`501`.

* :program:`tiffmedian`: avoid zero num_colors
  (:issue:`477`).

* :program:`fax2ps`: fix buffer overflow in qsort function pcompar
  (:issue:`475`).

* :program:`tiffset`: get filesize to allocate only the required memory
  (:issue:`241`).

* :program:`tiffcrop`: fix :issue:`553` by considering error return of writeSelections().

* tif_ovrcache.c: check :c:func:`TIFFSetSubDirectory` return value (CID 1524573).


Contributed software changes
----------------------------

None