$(this.promiser) not evaluated for exec_program

This was already reported as https://cfengine.com/bugtracker/bug_view_advanced_page.php?bug_id=294

Is is still broken in 3.5.2 and renders exec_command unusable for file_select.

Here's some example code:

<pre>
body common control
{
bundlesequence =>

{ "main" }

;
inputs =>

{ "$(sys.workdir)/inputs/lib/cfengine_stdlib.cf", }

;
}

bundle agent main
{
files:
any::
"/tmp"
copy_from => local_cp("$(sys.workdir)/inputs"),
file_select => by_exec_cmd,
depth_search => recurse("1"),
classes => if_repaired("copied_files");

}

body file_select by_exec_cmd {
leaf_name =>

{ ".*\.cf" }

;
exec_program => "/bin/ls $(this.promiser)";
file_result => "leaf_name.exec_program";
}
</pre>

yields:
<pre>
$ /var/cfengine/bin/cf-agent -f $(pwd)/test_this.cf
/bin/ls: cannot access $(this.promiser): No such file or directory
/bin/ls: cannot access $(this.promiser): No such file or directory
[...]
</pre>

This is more or less the example from the documentation https://cfengine.com/docs/3.5/reference-promise-types-files.html#exec_program, so please make this work, we need it desparately.

Thanks,
Sven