imap: quiet uninitialized variable warning on FETCH

This was triggered by blindly trying to FETCH an MSN (not
"UID FETCH") on an empty dummy inbox.  It's harmless, and
probably triggered by a wayward client or misbehaving bot.

1 files changed, 4 insertions, 0 deletions

diff --git a/t/imapd.t b/t/imapd.t
index cb95fa5d..c1c52839 100644
--- a/t/imapd.t
+++ b/t/imapd.t
@@ -371,6 +371,10 @@ EOF
         @hits = $mic->search('SENTSINCE' => '18-Apr-2020');
         is_deeply(\@hits, [], 'search on dummy with condition works');
         ok(!$mic->search('SENTSINCE' => '18-Abr-2020'), 'bad month fails');
+        $mic->Uid(0);
+        my $ret = $mic->fetch_hash(2, 'RFC822');
+        is_deeply($ret, {},
+                'MSN FETCH on empty dummy will not trigger warnings, later');
 }); # each_inbox
 
 # message sequence numbers :<