Leave a record another module's composition now holds, whatever its type, instead of removing it in the node's own apply; a removed module holds nothing back (issue 1944, issue 1945)

internal/agent/agent.go

@@ -409,6 +409,9 @@ func (a *Agent) heldOut(except string) []delivery.Composed {
 		if h, ok := a.running[m]; ok && h.Phase != delivery.PhaseRemoved {
 			continue
 		}
+		if w := a.wants[m]; w.Present && w.Want.Removed {
+			continue // a module the assigner removed holds nothing back
+		}
 		if w := a.wants[m]; w.Present && !w.Want.Removed && w.Want.FP == fp {
 			waiting[m] = c
 			continue

internal/agent/agent_test.go

@@ -676,3 +676,45 @@ func TestTheNodesOwnApplyHoldsOutAModuleThatMovedToItsOwnComposition(t *testing.
 		t.Fatalf("the others of the node's own apply were %v: systemd-resolved's resources would be removed", names)
 	}
 }
+
+// A module the assigner removed holds nothing back, its compositions still in the bucket or not: its resources are its
+// removal's to take (issue 1945).
+func TestARemovedModulesCompositionHoldsNothingBack(t *testing.T) {
+	b := newBed(t)
+	fp := fpOf("b")
+	rk, rraw, _ := composition(t, "gone", fp, false, file("gone", "x", "1"))
+	b.comps.before(rk, rraw)
+	gk, err := delivery.WantKey(node, "gone")
+	if err != nil {
+		t.Fatal(err)
+	}
+	graw, err := delivery.EncodeWant(delivery.Want{Removed: true})
+	if err != nil {
+		t.Fatal(err)
+	}
+	b.wants.before(gk, graw)
+	nk, nraw, ndig := composition(t, NodeModule, "", false)
+	nwk, _ := delivery.WantNodeKey(node)
+	nwraw, _ := delivery.EncodeNodeWant(delivery.NodeWant{Composed: ndig})
+	b.comps.before(nk, nraw)
+	b.wants.before(nwk, nwraw)
+	stop := b.run()
+	defer stop()
+	eventually(t, "the node's own not applied", func() bool {
+		for _, m := range b.appliedList() {
+			if m == NodeModule {
+				return true
+			}
+		}
+		return false
+	})
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	for _, others := range b.others {
+		for _, c := range others {
+			if c.Module == "gone" {
+				t.Fatal("a removed module's composition was held out")
+			}
+		}
+	}
+}