Say once after a restart that nothing waits, so an old retirement condition clears (issue 937)

The controller clears a provider's retire-waiting condition only on its
settled word, and a provider says settled only for a set its own memory
held. A provider restarted after the set stopped waiting (here: the
delivery of the grant-file fix) never says it, so the condition kept
asking the operator to approve retiring what nobody waits on. The first
pass of a process that finds every consumer asked now says settled once,
with no set; the controller clears both conditions on it.

modules/postgres/cmd/postgres-provider/retirement_test.go

@@ -121,6 +121,11 @@ func retirements(said []announced) []string {
 	return out
 }
 
+func noneWaits(a announced) bool {
+	c, _ := a.body["consumers"].([]map[string]any)
+	return a.body["change"] == ChangeSettled && len(c) == 0
+}
+
 func lastRetirement(t *testing.T, said []announced) map[string]any {
 	t.Helper()
 	for i := len(said) - 1; i >= 0; i-- {
@@ -521,3 +526,46 @@ func TestAFailingConsumerRetiredIsSaidRecovered(t *testing.T) {
 		t.Fatalf("%v", *said)
 	}
 }
+
+// everyWord is a world that keeps every word the provider announces.
+func everyWord(t *testing.T) (*world, *[]announced) {
+	w := newWorld(t)
+	var said []announced
+	w.h.Announce = func(e string, b map[string]any) { said = append(said, announced{e, b}) }
+	w.h.Node = "anchor"
+	return w, &said
+}
+
+// A restarted provider that finds every consumer it holds asked for says once that nothing waits, so the controller
+// clears a waiting condition an earlier process raised and this one never knew (issue 937); it says it no more.
+func TestARestartedProviderSaysOnceThatNothingWaits(t *testing.T) {
+	w, said := everyWord(t)
+	holding(w, 2)
+	w.pass()
+	w.pass()
+	var words []announced
+	for _, a := range *said {
+		if a.event == EventRetirement {
+			words = append(words, a)
+		}
+	}
+	if len(words) != 1 || !noneWaits(words[0]) || words[0].body["provider-node"] != w.h.Node {
+		t.Fatalf("said %+v, want one settled with no set", words)
+	}
+}
+
+// A provider whose own set waits does not say that nothing waits.
+func TestAProviderThatWaitsDoesNotSayNothingWaits(t *testing.T) {
+	w, said := everyWord(t)
+	w.a.inv.Active = []string{"c1", "c2", "c3", "c4", "c5"}
+	w.give(map[string]any{"as": "c1", "node": "anchor"})
+	w.settle()
+	for _, a := range *said {
+		if a.event == EventRetirement && noneWaits(a) {
+			t.Fatalf("said nothing waits while %v waited", w.h.r.waiting)
+		}
+	}
+	if w.h.r.waiting == nil {
+		t.Fatal("nothing waited: the test does not hold the case")
+	}
+}