Ignore freshness when serving queries on Leader

It doesn't make sense to check the last leader-contact time when the
node itself is the leader. Any read, when served by the leader, is going
to be within the freshness bound.

Fixes https://github.com/rqlite/rqlite/issues/1048

store/store.go

@@ -803,8 +803,8 @@ func (s *Store) Query(qr *command.QueryRequest) ([]*command.QueryRows, error) {
 		return nil, ErrNotLeader
 	}
 
-	if qr.Level == command.QueryRequest_QUERY_REQUEST_LEVEL_NONE && qr.Freshness > 0 &&
-		time.Since(s.raft.LastContact()).Nanoseconds() > qr.Freshness {
+	if s.raft.State() != raft.Leader && qr.Level == command.QueryRequest_QUERY_REQUEST_LEVEL_NONE &&
+		qr.Freshness > 0 && time.Since(s.raft.LastContact()).Nanoseconds() > qr.Freshness {
 		return nil, ErrStaleRead
 	}
 

store/store_test.go

@@ -1475,6 +1475,49 @@ func Test_MultiNodeExecuteQuery(t *testing.T) {
 	}
 }
 
+func Test_SingleNodeExecuteQueryFreshness(t *testing.T) {
+	s0, ln0 := mustNewStore(true)
+	defer os.RemoveAll(s0.Path())
+	defer ln0.Close()
+	if err := s0.Open(); err != nil {
+		t.Fatalf("failed to open single-node store: %s", err.Error())
+	}
+	defer s0.Close(true)
+	if err := s0.Bootstrap(NewServer(s0.ID(), s0.Addr(), true)); err != nil {
+		t.Fatalf("failed to bootstrap single-node store: %s", err.Error())
+	}
+	if _, err := s0.WaitForLeader(10 * time.Second); err != nil {
+		t.Fatalf("Error waiting for leader: %s", err)
+	}
+
+	er := executeRequestFromStrings([]string{
+		`CREATE TABLE foo (id INTEGER NOT NULL PRIMARY KEY, name TEXT)`,
+		`INSERT INTO foo(id, name) VALUES(1, "fiona")`,
+	}, false, false)
+	_, err := s0.Execute(er)
+	if err != nil {
+		t.Fatalf("failed to execute on single node: %s", err.Error())
+	}
+
+	_, err = s0.WaitForAppliedFSM(5 * time.Second)
+	if err != nil {
+		t.Fatalf("failed to wait for fsmIndex: %s", err.Error())
+	}
+	qr := queryRequestFromString("SELECT * FROM foo", false, false)
+	qr.Level = command.QueryRequest_QUERY_REQUEST_LEVEL_NONE
+	qr.Freshness = mustParseDuration("100h").Nanoseconds()
+	r, err := s0.Query(qr)
+	if err != nil {
+		t.Fatalf("failed to query leader node: %s", err.Error())
+	}
+	if exp, got := `["id","name"]`, asJSON(r[0].Columns); exp != got {
+		t.Fatalf("unexpected results for query\nexp: %s\ngot: %s", exp, got)
+	}
+	if exp, got := `[[1,"fiona"]]`, asJSON(r[0].Values); exp != got {
+		t.Fatalf("unexpected results for query\nexp: %s\ngot: %s", exp, got)
+	}
+}
+
 func Test_MultiNodeExecuteQueryFreshness(t *testing.T) {
 	s0, ln0 := mustNewStore(true)
 	defer os.RemoveAll(s0.Path())