Expansion of 'this' variable breaks within parametrized bodies called within bundles which are called with usebundle.

Hello,
I have problems concerning the expansion of the special 'this' variable when it is used inside a parametrized body called from a bundle which is itself called from another bundle with a 'usebundle' directive.

To illustrate this, consider the autonomous testcase below:

body common control {

bundlesequence => {"a"};

}


bundle agent a {

vars:
   "target_path" string => "/d1/d2/d3/my_file";
   "used_bundles" slist => {"b", "c"};

files:
   "/tmp/a/d1/d2/d3/my_file"
   create => "true";

   "/tmp/$(used_bundles)/d1/d2/d3/my_file"
   create => "true";

    "$(target_path)"
    copy_from => my_copy_with_param("/tmp");

methods:

   "XXX" usebundle => $(used_bundles);

}

bundle agent b {

 files:

    "$(a.target_path)"
    copy_from => my_copy_without_param();

}

bundle agent c {

 files:

    "$(a.target_path)"
    copy_from => my_copy_with_param("/tmp");

}

body copy_from my_copy_without_param() {
    source  => "/tmp/$(this.bundle)/$(this.promiser)";
    servers => { "localhost" };
    compare => "digest";
}

body copy_from my_copy_with_param(root) {
    source  => "/$(root)/$(this.bundle)/$(this.promiser)";
    servers => { "localhost" };
    compare => "digest";
}

The verbose logs are inside the attached file 'cf.log'.
To sum up, three cases are tested:

1. I use the parametrized body my_copy_with_param directly in the main a bundle
2. I use the unparametrized body my_copy_without_param wthin the b bundle called from the a bundle with a usebundle directive
3. I use parametrized body my_copy_with_param wthin the c bundle called from the a bundle with a usebundle directive

In the two bodies i use the variables this.bundle and this.promiser.

The two first cases are OK, the 'this' variable is correctly expanded as the calling bundle (a in the first case, b in the second case).
In the third case, the 'this' variable is not corrctly expanded, as it references the a bundle (the root bundle) whereas it should reference the c bundle, as it is the calling bundle. Il seems that the body parameter muddles in certain way the 'this' variable.

This bug, if it appears to be one, is potentially very harmful as a bundle (the c bundle in this case) never knows the context of its activation, directly in the bundlesequence or indirectly via a usebundle directive.