2.2.0 config files

[Brian Candler]

A colleague was upgrading some boxes from (I think) 2.1.10 to 2.2.0, and
says that expansions of the form %{Foo:-0} stopped working, and had to be
replaced with %{%{Foo}:-0}

Is that expected? I don't see anything in the ChangeLog, apart from
2.2.0 claims to be "100% configuration file compatible with 2.1.x"

Thanks,

Brian