The relationship between an object X and another object Y that
replaces the object X is defined only within the scope of a
single repository.
The exception in reachability rule around these replacement objects
is also local to a repository (i.e. if traversal from refs reaches
X, then both X and Y are reachable and need to be kept from gc).
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
