v2writable: support purging messages from git entirely

Purging existing messages is fairly straightforward since we can
take advantage of Xapian and lookup the git object_id with it.

Unfortunately, purging an already "removed" message (which is
no longer in Xapian) is not as easy and we'll need to expose
->purge_oids to purge by the git object_id (currently SHA-1).

Furthermore, we expire reflogs and prune in hopes a dumb HTTP
client won't get the object.

1 files changed, 7 insertions, 0 deletions

diff --git a/t/v2writable.t b/t/v2writable.t
index c48f060e..0eda432a 100644
--- a/t/v2writable.t
+++ b/t/v2writable.t
@@ -231,4 +231,11 @@ EOF
         ok(!$@, '->done is idempotent');
 }
 
+{
+        ok($im->add($mime), 'add message to be purged');
+        local $SIG{__WARN__} = sub {};
+        ok($im->purge($mime), 'purged message');
+        $im->done;
+}
+
 done_testing();