processpipe: allow synchronous close to set $?

To get rid of the ugly $PublicInbox::DS::in_loop localization
in MboxReader, we'll distinguish between ->CLOSE and ->DESTROY
with ProcessPipe.

If we end up closing via ->DESTROY, we'll assume the caller will
want to deal with $? asynchronously via the event loop (or not
even care about $?).

If we hit ->CLOSE directly, we'll assume the caller called
close() and wants to check $? synchronously.

Note: wantarray doesn't seem to propagate into tied methods,
otherwise I'd be relying on that.

1 files changed, 38 insertions, 0 deletions

diff --git a/t/spawn.t b/t/spawn.t
index 552bba33..d97e13a6 100644
--- a/t/spawn.t
+++ b/t/spawn.t
@@ -98,6 +98,44 @@ EOF
         isnt($?, 0, '$? set properly: '.$?);
 }
 
+{ # ->CLOSE vs ->DESTROY waitpid caller distinction
+        my @c;
+        my $fh = popen_rd(['true'], undef, { cb => sub { @c = caller } });
+        ok(close($fh), '->CLOSE fired and successful');
+        ok(scalar(@c), 'callback fired by ->CLOSE');
+        ok(grep(!m[/PublicInbox/DS\.pm\z], @c), 'callback not invoked by DS');
+
+        @c = ();
+        $fh = popen_rd(['true'], undef, { cb => sub { @c = caller } });
+        undef $fh; # ->DESTROY
+        ok(scalar(@c), 'callback fired by ->DESTROY');
+        ok(grep(!m[/PublicInbox/ProcessPipe\.pm\z], @c),
+                'callback not invoked by ProcessPipe');
+}
+
+{ # children don't wait on siblings
+        use POSIX qw(_exit);
+        pipe(my ($r, $w)) or BAIL_OUT $!;
+        my $cb = sub { warn "x=$$\n" };
+        my $fh = popen_rd(['cat'], undef, { 0 => $r, cb => $cb });
+        my $pp = tied *$fh;
+        my $pid = fork // BAIL_OUT $!;
+        local $SIG{__WARN__} = sub { _exit(1) };
+        if ($pid == 0) {
+                local $SIG{__DIE__} = sub { _exit(2) };
+                undef $fh;
+                _exit(0);
+        }
+        waitpid($pid, 0);
+        is($?, 0, 'forked process exited');
+        my @w;
+        local $SIG{__WARN__} = sub { push @w, @_ };
+        close $w;
+        close $fh;
+        is($?, 0, 'cat exited');
+        is_deeply(\@w, [ "x=$$\n" ], 'callback fired from owner');
+}
+
 SKIP: {
         eval {
                 require BSD::Resource;