mesh-delivery takes an empty answer to a check ask as a refusal (issue 1115)

modules/mesh-delivery/cmd/mesh-delivery/fakes_test.go

@@ -109,6 +109,8 @@ type fakeController struct {
 	moves      map[string][]string
 	plans      int
 	down       bool
+	// emptyCheck makes Check answer with no id and no error, as the port does when the answer holds none.
+	emptyCheck bool
 	// walkReads counts the reads of the controller's walks (Walks).
 	walkReads int
 	// checkReady is the ready flag of each member of each check asked.
@@ -185,6 +187,9 @@ func (c *fakeController) Check(group string, ms []Member) (string, error) {
 	}
 	c.asked++
 	id := fmt.Sprintf("check-%d", c.asked)
+	if c.emptyCheck {
+		id = ""
+	}
 	var heads []string
 	for _, m := range ms {
 		heads = append(heads, m.ID)

modules/mesh-delivery/cmd/mesh-delivery/holder.go

@@ -1942,6 +1942,10 @@ func (h *Holder) askOwnCheck(id string, m Member, why string) {
 		h.Logf("[mesh-delivery] %s's check cannot be asked yet: %v", id, err)
 		return
 	}
+	if asked == "" {
+		h.Logf("[mesh-delivery] %s's check was asked and the controller's answer held no id: taken as refused, asked again in a minute at most", id)
+		return
+	}
 	delete(h.askTried, id)
 	d := h.deliveries[id]
 	if d == nil || d.State != Proposed || d.Check != nil || askedCheck(d) {

modules/mesh-delivery/cmd/mesh-delivery/timers_test.go

@@ -192,3 +192,20 @@ func TestAKeptAskWithNoIdAndNoStandingVerdictIsAskedAgainAtOnce(t *testing.T) {
 		t.Fatalf("not asked again: %+v %v", d.CheckAsk, w.ctl.checks)
 	}
 }
+
+func TestAnEmptyAnswerToACheckAskIsARefusalAskedAtMostOnceAMinute(t *testing.T) {
+	w := newWorld(t)
+	w.ctl.emptyCheck = true
+	w.h.PullUpdated(pr("novox/app", 7, readyHead, "feat/x", "src/a.go"))
+	id := IDOf("novox/app", readyHead)
+	w.settleAll()
+	w.settleAll()
+	if len(w.ctl.checks) != 1 || w.delivery(id).CheckAsk != nil || len(w.forge.notesOn(readyHead)) > 1 {
+		t.Fatalf("asked %v, ask kept %v; wanted one ask and none kept", w.ctl.checks, w.delivery(id).CheckAsk)
+	}
+	w.later(time.Minute)
+	w.settleAll()
+	if len(w.ctl.checks) != 2 {
+		t.Fatalf("not asked again after the minute: %v", w.ctl.checks)
+	}
+}