search: always sort thread results in ascending time order

This makes life easier for the threading algorithm, as we can
use the implied ordering of timestamps to avoid temporary ghosts
and resulting container vivication.

This would've also allowed us to hide the bug (in most cases)
fixed by the patch titled "thread: last Reference always wins",
in case that needs to be reverted due to infinite looping.

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/PublicInbox/Search.pm b/lib/PublicInbox/Search.pm
index 8da30c19..5e6bfc68 100644
--- a/lib/PublicInbox/Search.pm
+++ b/lib/PublicInbox/Search.pm
@@ -158,6 +158,11 @@ sub get_thread {
         }
         $opts ||= {};
         $opts->{limit} ||= 1000;
+
+        # always sort threads by timestamp, this makes life easier
+        # for the threading algorithm (in SearchThread.pm)
+        $opts->{asc} = 1;
+
         _do_enquire($self, $qtid, $opts);
 }