rehearsal mark and c major

[Graham Percival]

Rehearsal marks (at the beginning of a line) are incorrectly placed when
there is no key signature(c major, a minor).  See the following score:
----
\score{ \notes {
a a a a a a a a a a a a \break
\mark A
a a a a a a a a a a a a \break
\mark \default
\key g \major
a a a a a a a a a a a a \break
\mark \default
\key f \major
a a a a a a a a a a a a \break
\mark \default
\key c \major
a a a a a a a a a a a a \break
}}
----

HTH,
- Graham