spawn: correctly handle error code

Both the C and pure Perl implementions of `pi_fork_exec'
returns `-1' on error, not `undef'.

diff --git a/lib/PublicInbox/Spawn.pm b/lib/PublicInbox/Spawn.pm
index 2d9f734c1b6df46331a86f2802b1aa3972fee004..ad6be1878a0fd899c8a7543645cbae2285bf6fa2 100644 (file)
--- a/lib/PublicInbox/Spawn.pm
+++ b/lib/PublicInbox/Spawn.pm
@@ -210,7 +210,7 @@ sub spawn ($;$$) {
        }
        my $cd = $opts->{'-C'} // ''; # undef => NULL mapping doesn't work?
        my $pid = pi_fork_exec($redir, $f, $cmd, \@env, $rlim, $cd);
        }
        my $cd = $opts->{'-C'} // ''; # undef => NULL mapping doesn't work?
        my $pid = pi_fork_exec($redir, $f, $cmd, \@env, $rlim, $cd);

-       die "fork_exec failed: $!\n" unless defined $pid;
+       die "fork_exec failed: $!\n" unless $pid > 0;

        $pid;
 }
 
        $pid;
 }