t/lei-refresh-mail-sync: speed up test on FreeBSD 12

And improve reliability while we're at it.  It seems closing a
TCP listen socket on FreeBSD 12.2 doesn't cause connect()-ing
clients to fail.  This happens regardless of whether a socket is
IPv4 or IPv6

This non-failure was causing tests to timeout slowly on the
client side instead of failing immediately.  We now fork a new
process which does nothing but accept() + shutdown() to emulate
a dead server.

Reliability improves on all OSes since there's never a point in
time when another process can bind the socket.

1 files changed, 19 insertions, 16 deletions

diff --git a/t/lei-refresh-mail-sync.t b/t/lei-refresh-mail-sync.t
index 43fbc50a..ea83a513 100644
--- a/t/lei-refresh-mail-sync.t
+++ b/t/lei-refresh-mail-sync.t
@@ -88,12 +88,9 @@ SKIP: {
                 $sock_cls //= ref($s);
                 my $cmd = [ "-$x", '-W0', "--stdout=$home/$x.out",
                         "--stderr=$home/$x.err" ];
-                my $td = start_script($cmd, $env, { 3 => $s}) or xbail("-$x");
-                $srv->{$x} = {
-                        addr => (my $scalar = tcp_host_port($s)),
-                        td => $td,
-                        cmd => $cmd,
-                };
+                my $td = start_script($cmd, $env, { 3 => $s }) or xbail("-$x");
+                my $addr = tcp_host_port($s);
+                $srv->{$x} = { addr => $addr, td => $td, cmd => $cmd, s => $s };
         }
         my $url = "imap://$srv->{imapd}->{addr}/t.v1.0";
         lei_ok 'import', $url, '+L:v1';
@@ -123,20 +120,26 @@ SKIP: {
         $before = $lei_out;
         delete $srv->{imapd}->{td}; # kill + join daemon
 
+        my $pid = fork // xbail "fork";
+        if ($pid == 0) { # dummy server to kill new connections
+                $SIG{TERM} = sub { POSIX::_exit(0) };
+                $srv->{imapd}->{s}->blocking(1);
+                while (1) {
+                        my $caddr = accept(my $c, $srv->{imapd}->{s}) // next;
+                        shutdown($c, 2);
+                }
+                POSIX::_exit(0);
+        }
+        my $ar = PublicInbox::AutoReap->new($pid);
         ok(!(lei 'refresh-mail-sync', $url), 'URL fails on dead -imapd');
         ok(!(lei 'refresh-mail-sync', '--all'), '--all fails on dead -imapd');
+        $ar->kill for qw(avoid sig wake miss-no signalfd or EVFILT_SIG);
+        $ar->join('TERM');
 
-        # restart server (somewhat dangerous since we released the socket)
-        my $listen = $sock_cls->new(
-                ReuseAddr => 1,
-                Proto => 'tcp',
-                Type => Socket::SOCK_STREAM(),
-                Listen => 1024,
-                Blocking => 0,
-                LocalAddr => $srv->{imapd}->{addr},
-        ) or xbail "$sock_cls->new: $!";
         my $cmd = $srv->{imapd}->{cmd};
-        $srv->{imapd}->{td} = start_script($cmd, $env, { 3 => $listen }) or
+        my $s = $srv->{imapd}->{s};
+        $s->blocking(0);
+        $srv->{imapd}->{td} = start_script($cmd, $env, { 3 => $s }) or
                 xbail "@$cmd";
         lei_ok 'refresh-mail-sync', '--all';
         lei_ok 'inspect', "blob:$oid";