Up to libtiff 4.4.0, the LIBTIFF_CURRENT version was 13, and LIBTIFF_AGE was 8.
As of 4.5.0, LIBTIFF_CURRENT was decremented to 6, and LIBTIFF_AGE was reset.
This change has major implications for Mach-O dynamic libraries on MacOS.

In order to maintain compatibility with other libraries that were
linked with previous versions of libtiff, these must be reset back to the
previous values, with LIBTIFF_CURRENT being incremented by 1. The maintainers
of libtiff decided to increment the SO version as a result of the private
symbol that was removed in libtiff 4.4.0.

This must be done because existing packages that are linked with older versions
of libtiff require a compatibility_version that is greater than or equal to the
version number in the dependency being loaded. The change to LIBTIFF_CURRENT
causes this version to be lower than before, resulting in the dynamic linker
being unable to load the library. This is because the compatbility and current
version values used by libtool are derived from the LIBTIFF_CURRENT value.

This fix sets LIBTIFF_CURRENT to the value used in libtiff 4.4.0, plus 1 (14).
The LIBTIFF_AGE value must remain the same, as the SO_MAJOR version is later
calculated by (LIBTIFF_CURRENT - LIBTIFF_AGE). This is how the SO version
number (6) is determined (e.g., libtiff.6.dylib).

When libtiff alters the LIBTIFF_CURRENT or LIBTIFF_AGE values, this patch will
need to be updated (it will fail to apply when that occurs). Hopefully, changes
can be made upstream to better address this before that happens.

Update to 4.5.1 from 4.5.0 : no changes to the API, as a result, only 
LIBTIFF_REVISION was incremented. Therefore LIBTIFF_REVISION is incremented to 1.

--- configure	2023-01-10 14:40:57.000000000 -0700
+++ configure 	2023-01-10 14:15:28.000000000 -0700
@@ -3721,9 +3721,9 @@
 LIBTIFF_VERSION=$LIBTIFF_MAJOR_VERSION.$LIBTIFF_MINOR_VERSION.$LIBTIFF_MICRO_VERSION$LIBTIFF_ALPHA_VERSION
 LIBTIFF_RELEASE_DATE=`date +"%Y%m%d"`
 
-LIBTIFF_CURRENT=6
+LIBTIFF_CURRENT=14
 LIBTIFF_REVISION=1
-LIBTIFF_AGE=0
+LIBTIFF_AGE=8 
 LIBTIFF_VERSION_INFO=$LIBTIFF_CURRENT:$LIBTIFF_REVISION:$LIBTIFF_AGE
 
 # This is a special hack for OpenBSD and MirOS systems. The dynamic linker
