index: v2: parallel by default

InboxWritable should only set $v2w->{parallel} if the $parallel
flag is defined to 0 or 1.  We want indexing a new inbox to
utilize SMP, just like --reindex.

-index once again allows -j0/--jobs=0 to force single-process
use, and we'll be ensuring that works in tests to maintain
performance on small systems.

Fixes: 61a2fff5b34a3e32 ("admin: move index_inbox over")

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/PublicInbox/InboxWritable.pm b/lib/PublicInbox/InboxWritable.pm
index 3558403b..c54be046 100644
--- a/lib/PublicInbox/InboxWritable.pm
+++ b/lib/PublicInbox/InboxWritable.pm
@@ -57,7 +57,7 @@ sub importer {
                 die "v2 not supported: $@\n" if $@;
                 my $opt = $self->{-creat_opt};
                 my $v2w = PublicInbox::V2Writable->new($self, $opt);
-                $v2w->{parallel} = $parallel;
+                $v2w->{parallel} = $parallel if defined $parallel;
                 $v2w;
         } elsif ($v == 1) {
                 my @arg = (undef, undef, undef, $self);