Fix redownloads for delisted iOS apps

pkg/appstore/appstore_download_product.go

@@ -99,12 +99,20 @@ func (t *appstore) sendDownloadProduct(ctx context.Context, acc Account, app App
 
 	if externalVersionID == "" && (platform == "" || platform == PlatformIPhone || platform == PlatformIPad) {
 		// Unpinned redownloads can fail or return a tvOS package. Select
-		// the current iOS build before sending.
+		// the current iOS build when the catalog has an offer.
 		if platform == "" {
 			platform = PlatformIPhone
 		}
 
 		externalVersionID, err = t.lookupLatestExternalVersionID(acc, app, platform)
+		if errors.Is(err, errIOSCatalogAppNotFound) {
+			// A delisted app can still be available to this account. Try once
+			// without a version; Download validates the returned package's platform.
+			res, err := t.sendUnpinnedRedownload(ctx, redownload, acc, app, guid)
+
+			return res, platform, err
+		}
+
 		if err != nil {
 			return res, platform, fmt.Errorf("failed to resolve latest iOS version for redownload: %w", err)
 		}
@@ -130,6 +138,33 @@ func (t *appstore) sendDownloadProduct(ctx context.Context, acc Account, app App
 	return redownloadRes, platform, nil
 }
 
+func (t *appstore) sendUnpinnedRedownload(ctx context.Context, endpoint downloadProductEndpoint, acc Account, app App, guid string) (http.Result[downloadResult], error) {
+	requestContext, cancel := context.WithTimeout(ctx, http.DefaultAuthenticationTimeout)
+	defer cancel()
+
+	if err := requestContext.Err(); err != nil {
+		return http.Result[downloadResult]{}, fmt.Errorf("redownload request canceled: %w", err)
+	}
+
+	request := t.downloadProductRequest(endpoint, acc, app, guid, "")
+	request.Context = requestContext
+
+	res, err := t.downloadClient.Send(request)
+	if err != nil {
+		return res, fmt.Errorf("failed to send redownload request: %w", err)
+	}
+
+	if err := validateDownloadResponse(res, app, "", "redownload"); err != nil {
+		return res, err
+	}
+
+	if res.Data.FailureType == "" && res.Data.Items[0].URL == "" {
+		return res, errors.New("redownload response has no package URL")
+	}
+
+	return res, nil
+}
+
 func isEmptyRedownloadError(err error) bool {
 	var unexpected *http.UnexpectedResponseError
 
@@ -151,10 +186,12 @@ func (t *appstore) sendUpdateProduct(endpoint string, acc Account, app App, guid
 		return res, fmt.Errorf("failed to send update request: %w", err)
 	}
 
-	return res, validateVersionedDownloadResponse(res, app, externalVersionID, "update")
+	return res, validateDownloadResponse(res, app, externalVersionID, "update")
 }
 
-func validateVersionedDownloadResponse(res http.Result[downloadResult], app App, externalVersionID, source string) error {
+// An empty externalVersionID allows the server to select a version while retaining
+// the app identity checks. Explicit and catalog-selected versions must match.
+func validateDownloadResponse(res http.Result[downloadResult], app App, externalVersionID, source string) error {
 	if res.Data.FailureType != "" {
 		return nil
 	}
@@ -173,7 +210,7 @@ func validateVersionedDownloadResponse(res http.Result[downloadResult], app App,
 
 	metadata := res.Data.Items[0].Metadata
 	if fmt.Sprint(metadata["itemId"]) != fmt.Sprint(app.ID) ||
-		fmt.Sprint(metadata["softwareVersionExternalIdentifier"]) != externalVersionID {
+		(externalVersionID != "" && fmt.Sprint(metadata["softwareVersionExternalIdentifier"]) != externalVersionID) {
 		return fmt.Errorf("%s response does not match the requested app or version", source)
 	}
 

pkg/appstore/appstore_download_product_test.go

@@ -365,7 +365,7 @@ var _ = Describe("AppStore (Download Product)", func() {
 			Expect(err).To(MatchError(ContainSubstring("failed to resolve latest iOS version for redownload")))
 		})
 
-		It("does not send an unpinned request when the app is absent from the catalog", func() {
+		It("does not send an unpinned request when the public catalog response is empty", func() {
 			mockPlatformClient.EXPECT().Send(gomock.Any()).
 				Return(http.Result[platformVersionLookupResult]{StatusCode: gohttp.StatusOK}, nil).Times(4)
 

pkg/appstore/appstore_ios_version_lookup.go

@@ -11,6 +11,9 @@ import (
 	"github.com/majd/ipatool/v2/pkg/http"
 )
 
+// Only a catalog 404 confirms absence; empty or malformed metadata is an error.
+var errIOSCatalogAppNotFound = errors.New("iOS catalog lookup returned HTTP 404")
+
 type catalogVersionLookupItem struct {
 	ID         string `json:"id,omitempty"`
 	Type       string `json:"type,omitempty"`
@@ -36,6 +39,10 @@ func (t *appstore) lookupLatestIOSExternalVersionID(app App, countryCode string,
 		return "", fmt.Errorf("iOS catalog lookup request failed: %w", err)
 	}
 
+	if res.StatusCode == gohttp.StatusNotFound {
+		return "", errIOSCatalogAppNotFound
+	}
+
 	if res.StatusCode != gohttp.StatusOK {
 		return "", fmt.Errorf("iOS catalog lookup returned HTTP %d", res.StatusCode)
 	}

pkg/appstore/appstore_kbsync.go

@@ -139,7 +139,7 @@ func (t *appstore) sendEntDownloadRequest(ctx context.Context, endpoint download
 		return res, NewErrorWithMetadata(fmt.Errorf("received ent/download error: %s", res.Data.FailureType), res)
 	}
 
-	if err := validateVersionedDownloadResponse(res, app, versionID, "ent/download"); err != nil {
+	if err := validateDownloadResponse(res, app, versionID, "ent/download"); err != nil {
 		return res, err
 	}
 

pkg/appstore/appstore_kbsync_test.go

@@ -376,6 +376,31 @@ var _ = Describe("AppStore (preferred kbsync download)", func() {
 		Expect(generated).To(BeZero())
 	})
 
+	It("reaches unpinned redownload after the preferred catalog lookup and volumeStore miss", func() {
+		bag.URLBag.RedownloadEndpoint = testRedownloadEndpoint
+		bag.URLBag.UpdateEndpoint = testUpdateEndpoint
+		gomock.InOrder(
+			bags.EXPECT().Send(gomock.Any()).Return(http.Result[bagResult]{StatusCode: gohttp.StatusOK, Data: bag}, nil),
+			platforms.EXPECT().Send(gomock.Any()).Return(http.Result[platformVersionLookupResult]{StatusCode: gohttp.StatusOK}, nil).Times(3),
+			platforms.EXPECT().Send(gomock.Any()).Return(http.Result[platformVersionLookupResult]{StatusCode: gohttp.StatusNotFound}, nil),
+			downloads.EXPECT().Send(gomock.Any()).Do(func(req http.Request) {
+				Expect(req.URL).To(ContainSubstring("volumeStoreDownloadProduct"))
+				Expect(req.Payload.(*http.XMLPayload).Content).NotTo(HaveKey("externalVersionId"))
+			}).Return(unavailable, nil),
+			platforms.EXPECT().Send(gomock.Any()).Return(http.Result[platformVersionLookupResult]{StatusCode: gohttp.StatusOK}, nil).Times(3),
+			platforms.EXPECT().Send(gomock.Any()).Return(http.Result[platformVersionLookupResult]{StatusCode: gohttp.StatusNotFound}, nil),
+			downloads.EXPECT().Send(gomock.Any()).Do(func(req http.Request) {
+				Expect(req.URL).To(Equal(testRedownloadEndpoint + "?guid=" + guid))
+				Expect(req.Payload.(*http.XMLPayload).Content).NotTo(HaveKey("appExtVrsId"))
+			}).Return(success, nil),
+		)
+		actual, platform, err := store.sendDownloadProduct(context.Background(), account, app, guid, "", "")
+		Expect(err).NotTo(HaveOccurred())
+		Expect(actual).To(Equal(success))
+		Expect(platform).To(Equal(PlatformIPhone))
+		Expect(generated).To(BeZero())
+	})
+
 	It("does not send credentials to an invalid preferred endpoint and falls back", func() {
 		bag.URLBag.EntDownloadEndpoint = "https://example.com/WebObjects/DownloadDispatch.woa/wa/ent/download"
 		gomock.InOrder(