A merge on the controller's own path never shares a batch with one that waits for the delivery's word (hq ADR 0276, decided during the build)

cmd/mesh-controller/batches_test.go

@@ -669,3 +669,92 @@ func TestTheCatchUpKeepsWhatACutMadeHistory(t *testing.T) {
 		t.Fatalf("the merge made before the cut and heard after it was dropped: %v %v", kept, err)
 	}
 }
+
+// A merge on the controller's own path never shares a batch with one that waits for mesh-delivery's word
+// (decided during the build, 2026-10-10): the two are batches of their own, cut one after the other; a walk on
+// the own path folds no waiting catalogue walk but batches its merges again behind it; the catalogue's walk
+// still waits for the word, so no catalogue delivery skips its turn.
+func TestAMergeOnTheControllersPathNeverSharesABatch(t *testing.T) {
+	open := windowed(t)
+	asked := asksWithPaths(t)
+	ctx := t.Context()
+	if err := open.inventory.RegisterModule(ctx, catalogue.Manifest{Module: "mesh-delivery", Version: "1",
+		Claims: []catalogue.Claim{{Name: catalogue.DeliverySeat, Scope: catalogue.ScopeMesh}}},
+		inventory.Source{Repository: "novox/mesh-catalog", Seat: "git", Path: "modules/mesh-delivery", Ref: "main",
+			BuiltFrom: "c0", Head: "c0"}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := open.inventory.Assign(ctx, "anchor", "mesh-delivery"); err != nil {
+		t.Fatal(err)
+	}
+	hear(t, open, catalogueMerge("aaaa0001", "app", t0), t0)
+	hear(t, open, repoMerge("mesh-controller", "k1", t0.Add(10*time.Second)), t0.Add(10*time.Second))
+	hear(t, open, catalogueMerge("bbbb0002", "notes", t0.Add(20*time.Second)), t0.Add(20*time.Second))
+	_, bs := walks(t, open)
+	var ownBatch, catalogueBatch inventory.Plan
+	for _, b := range bs {
+		if b.OwnPath() {
+			ownBatch = b
+		} else {
+			catalogueBatch = b
+		}
+	}
+	if len(bs) != 2 || ownBatch.ID == "" || catalogueBatch.ID == "" || len(catalogueBatch.Delivery.Merges) != 2 ||
+		len(ownBatch.Delivery.Merges) != 1 {
+		t.Fatalf("a controller merge and two catalogue merges in one window: %+v", bs)
+	}
+	if !strings.Contains(batchWords(ownBatch, t0.Add(30*time.Second)), "own path") {
+		t.Fatalf("the own-path batch does not say so: %q", batchWords(ownBatch, t0.Add(30*time.Second)))
+	}
+	// The catalogue batch, the older, is cut first and waits for its word; the controller's batch is cut next:
+	// the waiting walk is batched again behind it, not folded into it.
+	cutAt(t, open, t0.Add(2*time.Minute))
+	ws, _ := walks(t, open)
+	if len(ws) != 1 || !ws[0].Waiting() {
+		t.Fatalf("the catalogue batch was not cut into a waiting walk: %+v", ws)
+	}
+	catalogueWalk := ws[0]
+	cutAt(t, open, t0.Add(2*time.Minute+5*time.Second))
+	ws, bs = walks(t, open)
+	var ownWalk inventory.Plan
+	for _, w := range ws {
+		if w.Open() {
+			ownWalk = w
+		}
+	}
+	if ownWalk.ID == "" || ownWalk.Waiting() || ownWalk.CommitOf("novox/mesh-controller") != "k1" {
+		t.Fatalf("the controller's batch was not cut into a started walk: %+v", ws)
+	}
+	for _, m := range []string{"app", "notes"} {
+		if _, in := ownWalk.Modules[m]; in {
+			t.Fatalf("the controller's walk builds %s, a catalogue module: it skipped its turn", m)
+		}
+	}
+	for _, a := range *asked {
+		if a[1] == "modules/app" || a[1] == "modules/notes" {
+			t.Fatalf("a catalogue module was asked without the word: %v", *asked)
+		}
+	}
+	folded, _ := open.inventory.PlanByID(ctx, catalogueWalk.ID)
+	if folded.State != inventory.PlanSuperseded || len(bs) != 1 || folded.Delivery.TakenOverBy != bs[0].ID ||
+		bs[0].State != inventory.PlanQueued || bs[0].Delivery.Batch.Behind != ownWalk.ID || bs[0].OwnPath() ||
+		len(bs[0].Delivery.Merges) != 2 {
+		t.Fatalf("the waiting catalogue walk is %s (taken over by %q); batches %+v", folded.State,
+			folded.Delivery.TakenOverBy, bs)
+	}
+	// The controller's walk done, the catalogue batch is cut and waits for its word with both merges.
+	ownWalk.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &ownWalk); err != nil {
+		t.Fatal(err)
+	}
+	cutAt(t, open, t0.Add(3*time.Minute))
+	ws, bs = walks(t, open)
+	if len(bs) != 0 || ws[0].ID != folded.Delivery.TakenOverBy || !ws[0].Waiting() || len(ws[0].Delivery.Merges) != 2 {
+		t.Fatalf("the catalogue batch was not cut into a waiting walk once the controller's ended: %+v %+v", ws, bs)
+	}
+	for _, m := range []string{"app", "notes"} {
+		if _, in := ws[0].Modules[m]; !in {
+			t.Fatalf("the catalogue walk does not build %s: %v", m, ws[0].Modules)
+		}
+	}
+}