xap_helper.pm: quiet undefined die at shutdown

Another attempt at doing what commit 35de8fdcbf290e25
(xap_helper.pm: quiet undefined warnings at shutdown, 2023-10-23)
tried to do.  It turns out perl croaks (not warn/carp) when it sees
an undefined file handle, here.

1 files changed, 5 insertions, 3 deletions

diff --git a/lib/PublicInbox/XapHelper.pm b/lib/PublicInbox/XapHelper.pm
index 55080abf..f7640f4c 100644
--- a/lib/PublicInbox/XapHelper.pm
+++ b/lib/PublicInbox/XapHelper.pm
@@ -179,11 +179,13 @@ sub recv_loop {
         local $SIG{TERM} = sub { undef $in };
         while (defined($in)) {
                 PublicInbox::DS::sig_setmask($workerset);
-                my @fds = do { # we undef $in in SIG{TERM}
-                        no strict 'refs';
-                        no warnings 'uninitialized';
+                my @fds = eval { # we undef $in in SIG{TERM}
                         $PublicInbox::IPC::recv_cmd->($in, $rbuf, 4096*33)
                 };
+                if ($@) {
+                        exit if !$in; # hit by SIGTERM
+                        die;
+                }
                 scalar(@fds) or exit(66); # EX_NOINPUT
                 die "recvmsg: $!" if !defined($fds[0]);
                 PublicInbox::DS::block_signals();