Page Move strategy fails if draft and published spaces are on a different level

E.g. consider the following setup:

• workflow uses the move strategy "Regardless of the type of document being moved, move its equivalent document(s)"
• Draft space is Drafts
• Public space is Topics.Published

and the following steps:

• Create a new Page "TestBeforeRename" in the drafts space
• Attach it to the workflow, select public location in the Topics.Published space and push it through the workflow
• Then rename the draft from "TestBeforeRename" to "TestAfterRename" 

Expected result:

• draft page is renamed at location Drafts.TestAfterRename.WebHome
• published page is renamed to Topics.Published.TestAfterRename.WebHome

Actual result

• draft page is indeed renamed at location Drafts.TestAfterRename.WebHome
• however on rename a warning appears in the log:

  Unable to compute new location for the document [testwiki » Topics » Published » TestBeforeMove » WebHome]

• published page stays at Topics.Published.TestBeforeRename.WebHome; only the title is changed to "TestAfterRename"