query: fix include-related.

mu-query.cc:
- make_related_enquire: don't include first query in qvec, we already have all
  thread IDs we need to query in thread_ds.
- run_related: always sort first query by date, explained by the comment.
- run_related: include qflags (in particular ascending vs descending) in
  leader_qflags.
- run_theaded: don't limit results to maxnum, that results in threads
  potentially being cut off.

mu-server.cc:
- output_sexp: don't limit results to maxnum so as to match the behaviour of
  mu find (and avoid cuttong off threads).

Fixes #1924 and #1911.

2 files changed, 15 insertions, 21 deletions

diff --git a/lib/mu-query.cc b/lib/mu-query.cc
index 5e4b0e8..59e9973 100644
--- a/lib/mu-query.cc
+++ b/lib/mu-query.cc
@@ -45,12 +45,11 @@ struct Query::Private {
 
         Xapian::Enquire make_enquire (const std::string& expr,
                                       MuMsgFieldId sortfieldid, QueryFlags qflags) const;
-        Xapian::Enquire make_related_enquire (const Xapian::Query& first_q,
-                                              const StringSet& thread_ids,
+        Xapian::Enquire make_related_enquire (const StringSet& thread_ids,
                                               MuMsgFieldId sortfieldid, QueryFlags qflags) const;
 
         Option<QueryResults> run_threaded (QueryResults&& qres, Xapian::Enquire& enq,
-                                            QueryFlags qflags, size_t max_size) const;
+                                           QueryFlags qflags) const;
         Option<QueryResults> run_singular (const std::string& expr, MuMsgFieldId sortfieldid,
                                            QueryFlags qflags, size_t maxnum) const;
         Option<QueryResults> run_related (const std::string& expr, MuMsgFieldId sortfieldid,
@@ -101,14 +100,13 @@ Query::Private::make_enquire (const std::string& expr,
 }
 
 Xapian::Enquire
-Query::Private::make_related_enquire (const Xapian::Query& first_q,
-                                      const StringSet& thread_ids,
+Query::Private::make_related_enquire (const StringSet& thread_ids,
                                       MuMsgFieldId sortfieldid, QueryFlags qflags)  const
 {
         Xapian::Enquire enq{store_.database()};
         static std::string pfx (1, mu_msg_field_xapian_prefix(MU_MSG_FIELD_ID_THREAD_ID));
 
-        std::vector<Xapian::Query> qvec{first_q};
+        std::vector<Xapian::Query> qvec;
         for (auto&& t: thread_ids)
                 qvec.emplace_back(pfx + t);
         Xapian::Query qr{Xapian::Query::OP_OR, qvec.begin(), qvec.end()};
@@ -129,7 +127,7 @@ struct ThreadKeyMaker: public Xapian::KeyMaker {
 
 Option<QueryResults>
 Query::Private::run_threaded (QueryResults&& qres, Xapian::Enquire& enq,
-                              QueryFlags qflags, size_t max_size) const
+                              QueryFlags qflags) const
 {
         const auto descending{any_of(qflags & QueryFlags::Descending)};
 
@@ -140,7 +138,7 @@ Query::Private::run_threaded (QueryResults&& qres, Xapian::Enquire& enq,
 
         DeciderInfo minfo;
         minfo.matches = qres.query_matches();
-        auto mset{enq.get_mset(0, max_size, {},
+        auto mset{enq.get_mset(0, store_.size(), {},
                                make_thread_decider(qflags, minfo).get())};
         mset.fetch();
 
@@ -172,7 +170,7 @@ Query::Private::run_singular (const std::string& expr, MuMsgFieldId sortfieldid,
 
         auto qres{QueryResults{mset, std::move(minfo.matches)}};
 
-        return threading ? run_threaded(std::move(qres), enq, qflags, maxnum) : qres;
+        return threading ? run_threaded(std::move(qres), enq, qflags) : qres;
 }
 
 static Option<std::string>
@@ -192,12 +190,12 @@ Query::Private::run_related (const std::string& expr, MuMsgFieldId sortfieldid,
         // moreover, in either threaded or non-threaded case, we sort the first
         // ("leader") query by date, i.e, we prefer the newest or oldest
         // (descending) messages.
-        const auto leader_qflags{QueryFlags::Leader};
+        const auto leader_qflags{QueryFlags::Leader | qflags};
         const auto threading{any_of(qflags & QueryFlags::Threading)};
 
         // Run our first, "leader" query
         DeciderInfo minfo{};
-        auto enq{make_enquire(expr, sortfieldid, leader_qflags)};
+        auto enq{make_enquire(expr, MU_MSG_FIELD_ID_DATE, leader_qflags)};
         const auto mset{enq.get_mset(0, maxnum, {},
                                      make_leader_decider(leader_qflags, minfo).get())};
 
@@ -214,13 +212,12 @@ Query::Private::run_related (const std::string& expr, MuMsgFieldId sortfieldid,
         // In the threaded-case, we search among _all_ messages, since complete
         // threads are preferred; no need to sort in that case since the search
         // is unlimited and the sorting happens during threading.
-        auto r_enq{make_related_enquire(enq.get_query(), minfo.thread_ids,
+        auto r_enq{make_related_enquire(minfo.thread_ids,
                                         threading ? MU_MSG_FIELD_ID_NONE : sortfieldid, qflags)};
         const auto r_mset{r_enq.get_mset(0, threading ? store_.size() : maxnum,
                                          {}, make_related_decider(qflags, minfo).get())};
         auto qres{QueryResults{r_mset, std::move(minfo.matches)}};
-
-        return threading ? run_threaded(std::move(qres), r_enq, qflags, maxnum) : qres;
+        return threading ? run_threaded(std::move(qres), r_enq, qflags) : qres;
 }
 
 
diff --git a/lib/mu-server.cc b/lib/mu-server.cc
index 32bac34..e418f66 100644
--- a/lib/mu-server.cc
+++ b/lib/mu-server.cc
@@ -86,7 +86,7 @@ struct Server::Private {
         void output_sexp(Sexp::List&& lst) const {
                 output_sexp(Sexp::make_list(std::move(lst)));
         }
-        size_t output_sexp (const QueryResults& qres, unsigned maxnum);
+        size_t output_sexp (const QueryResults& qres);
 
         //
         // handlers for various commands.
@@ -731,13 +731,10 @@ determine_docids (const Query& q, const Parameters& params)
 
 
 size_t
-Server::Private::output_sexp (const QueryResults& qres, unsigned maxnum)
+Server::Private::output_sexp (const QueryResults& qres)
 {
         size_t n{};
         for (auto&& mi: qres) {
-
-                if (n >= maxnum)
-                        break;
                 ++n;
                 auto msg{mi.floating_msg()};
                 if (!msg)
@@ -745,7 +742,7 @@ Server::Private::output_sexp (const QueryResults& qres, unsigned maxnum)
 
                 auto qm{mi.query_match()};
                 output_sexp(build_message_sexp(msg, mi.doc_id(),
-                                       qm, MU_MSG_OPTION_HEADERS_ONLY));
+                                               qm, MU_MSG_OPTION_HEADERS_ONLY));
         }
 
         return n;
@@ -796,7 +793,7 @@ Server::Private::find_handler (const Parameters& params)
         }
 
         {
-                const auto foundnum{output_sexp (*qres, maxnum)};
+                const auto foundnum{output_sexp (*qres)};
                 Sexp::List lst;
                 lst.add_prop(":found", Sexp::make_number(foundnum));
                 output_sexp(std::move(lst));