*search: simplify handling of Xapian term iterators

Xapian has always sorted termlist iterators, so we now:

1) break out of the iterator loop early on non-matches
2) avoid doing sorting ourselves

As a result, we'll also favor the wantarray forms of xap_terms
and all_terms to preserve sort order in most cases.

Confirmed by the Xapian maintainer: <20231201184844.GO4059@survex.com>

Link: https://lists.xapian.org/pipermail/xapian-discuss/2023-December/010013.html

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/PublicInbox/xh_mset.h b/lib/PublicInbox/xh_mset.h
index 056fe22b..4e97a284 100644
--- a/lib/PublicInbox/xh_mset.h
+++ b/lib/PublicInbox/xh_mset.h
@@ -11,7 +11,7 @@ static void emit_doc_term(FILE *fp, const char *pfx, Xapian::Document *doc)
 
         for (cur.skip_to(pfx); cur != end; cur++) {
                 std::string tn = *cur;
-                if (!starts_with(&tn, pfx, pfx_len)) continue;
+                if (!starts_with(&tn, pfx, pfx_len)) break;
                 fputc(0, fp);
                 fwrite(tn.data(), tn.size(), 1, fp);
         }