msgmap: fix atfork_* callbacks

Noticed while reindexing a largish v2 inbox in parallel on an
SSD which required checkpointing and respawning shard workers.

Fixes: f06e84220e5566e7 ("over+msgmap: do not store filename after DBI->connect")

1 files changed, 6 insertions, 0 deletions

diff --git a/t/msgmap.t b/t/msgmap.t
index f78070cc..1d7d1e87 100644
--- a/t/msgmap.t
+++ b/t/msgmap.t
@@ -64,4 +64,10 @@ my $tmp = $d->tmp_clone;
 is_deeply([$d->minmax], [$tmp->minmax], 'Cloned temporary DB matches');
 ok($tmp->mid_delete('spam@2'), 'temporary DB is writable');
 
+is(eval {
+        $tmp->atfork_prepare;
+        $tmp->atfork_parent;
+        'ok'
+}, 'ok', 'atfork_* work on tmp_clone');
+
 done_testing();