index: support --rethread switch to fix old indices

Older versions of public-inbox < 1.3.0 had subtly
different semantics around threading in some corner
cases.  This switch (when combined with --reindex)
allows us to fix them by regenerating associations.

1 files changed, 5 insertions, 2 deletions

diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index 83162509..e641ffd4 100644
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -723,6 +723,7 @@ sub _index_sync {
         my $pr = $opts->{-progress};
 
         my $xdb = $self->begin_txn_lazy;
+        $self->{over}->rethread_prepare($opts);
         my $mm = _msgmap_init($self);
         do {
                 $xlog = undef; # stop previous git-log via SIGPIPE
@@ -761,12 +762,14 @@ sub _index_sync {
                                 $xdb->set_metadata('last_commit', $newest);
                         }
                 }
+
+                $self->{over}->rethread_done($opts) if $newest; # all done
                 $self->commit_txn_lazy;
                 $git->cleanup;
                 $xdb = _xdb_release($self, $nr);
-                # let another process do some work... <
+                # let another process do some work...
                 $pr->("indexed $nr/$self->{ntodo}\n") if $pr && $nr;
-                if (!$newest) {
+                if (!$newest) { # more to come
                         $xdb = $self->begin_txn_lazy;
                         $dbh->begin_work if $dbh;
                 }