Stop replica defaulting loop from blocking suspension propagation

internal/controller/workloaddeployment_federator.go

@@ -404,6 +404,12 @@ func (r *WorkloadDeploymentFederator) upsertDownstreamDeployment(
 			delete(kd.Labels, computev1alpha.RuntimeClassLabel)
 		}
 		kd.Spec = deployment.Spec
+		// The cell initializes an unset replica target to minReplicas. Send that
+		// same target through Karmada so it does not repeatedly undo the cell's
+		// initialization and trigger a spec/status update loop.
+		if kd.Spec.Replicas == nil {
+			kd.Spec.Replicas = new(kd.Spec.ScaleSettings.MinReplicas)
+		}
 		// Propagate controller-managed annotations from the project WD to the
 		// downstream WD. The cell reads the expected-referenced-data annotation
 		// to gate-clear instances; without this copy it would never arrive.

internal/controller/workloaddeployment_federator_test.go

@@ -74,6 +74,34 @@ func testWorkloadDeployment(opts ...func(*computev1alpha.WorkloadDeployment)) *c
 	return wd
 }
 
+func TestUpsertDownstreamDeploymentReplicaTarget(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name     string
+		replicas *int32
+		want     int32
+	}{
+		{name: "defaults unset target to minimum", want: 3},
+		{name: "preserves explicit target", replicas: new(int32(5)), want: 5},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			deployment := testWorkloadDeployment()
+			deployment.Spec.ScaleSettings.MinReplicas = 3
+			deployment.Spec.Replicas = tc.replicas
+			karmadaClient := newKarmadaFakeClient()
+			r := &WorkloadDeploymentFederator{}
+
+			got, err := r.upsertDownstreamDeployment(context.Background(), karmadaClient, deployment, testKarmadaNSStr, "")
+			require.NoError(t, err)
+			require.NotNil(t, got.Spec.Replicas)
+			assert.Equal(t, tc.want, *got.Spec.Replicas)
+			assert.Equal(t, tc.replicas, deployment.Spec.Replicas, "project deployment must stay unchanged")
+		})
+	}
+}
+
 // withFinalizer adds the federator finalizer to the WorkloadDeployment.
 func withFinalizer(wd *computev1alpha.WorkloadDeployment) {
 	wd.Finalizers = append(wd.Finalizers, federatorFinalizer)