Sequences of 'replaced_by'

[Davide Liessi]

Dear all,
I'm renaming the py-python-poppler-qt4 port to py-poppler-qt4, as 
suggested by Peter Danecek.

I renamed the port to py-poppler-qt4 and added a py-python-poppler-qt4 
port with the obsolete PortGroup and suitable 'replaced_by' declarations:

replaced_by         py-poppler-qt4
subport py27-python-poppler-qt4 {
     replaced_by         py27-poppler-qt4
}
subport py34-python-poppler-qt4 {
     replaced_by         py34-poppler-qt4
}

Updating from py{27,34}-python-poppler-qt4 works correctly: i get the 
message 'pyXX-python-poppler-qt4 is replaced by pyXX-poppler-qt4' and 
the installation completes as expected.

However py-python-poppler-qt4 previously had support for Python 2.6, 3.2 
and 3.3.
I tried to upgrade from py26-python-poppler-qt4 and I got this:

--->  py26-python-poppler-qt4 is replaced by py27-python-poppler-qt4
--->  Fetching distfiles for py27-python-poppler-qt4
--->  Verifying checksums for py27-python-poppler-qt4
--->  Extracting py27-python-poppler-qt4
--->  Configuring py27-python-poppler-qt4
Error: py27-python-poppler-qt4 has been made obsolete by the port 
py27-poppler-qt4. Please install py27-poppler-qt4 instead.
Error: org.macports.configure for port py27-python-poppler-qt4 returned: 
obsolete port
Please see the log file for port py27-python-poppler-qt4 for details:
 
/opt/local/var/macports/logs/_Users_davide_ports_python_py-python-poppler-qt4/py27-python-poppler-qt4/main.log
Error: Unable to upgrade port: 1
To report a bug, follow the instructions in the guide:
     http://guide.macports.org/#project.tickets

Apparently 'port upgrade' cannot handle a sequence of 'replaced_by'.
Is this expected or did I do something wrong?

It is very unlikely that there are users with anything other than 
py27-... installed, given that the only port depending on 
py-python-poppler-qt4 is frescobaldi, which is installed by default with 
Python 2.7 (although it had until recently a python26 variant).
Anyway, if there is a way, I'd like to provide a clean upgrade path to 
users.

Best wishes.
Davide