CMP0105
-------

The :command:`set_property` ``APPEND`` argument handles empty values
properly.

In CMake 3.17 and below, empty values appended to properties were ignored. The 

The ``OLD`` behavior for this policy is to ignore the empty values when
appending to a property.

The ``NEW`` behavior of this policy is to add an empty element to the property
value like :command:`list`.

This policy was introduced in CMake version 3.18.  CMake version
|release| warns when the policy is not set and uses ``OLD`` behavior.
Use the :command:`cmake_policy` command to set it to ``OLD`` or ``NEW``
explicitly.

.. include:: DEPRECATED.txt
