fix: authenticate native media saves

src/app/components/image-viewer/ImageViewer.test.tsx

@@ -8,7 +8,7 @@ import type { IImageInfo } from '$types/matrix/common';
 
 const downloadMedia = vi.fn<(src: string) => Promise<Blob>>();
 const saveMediaToGallery =
-  vi.fn<(input: string, filename: string, mimeType: string) => Promise<void>>();
+  vi.fn<(input: Blob | string, filename: string, mimeType: string) => Promise<void>>();
 const toastMocks = vi.hoisted(() => ({
   showToast: vi.fn<(text: string, durationMs?: number) => void>(),
 }));
@@ -50,7 +50,7 @@ vi.mock('$utils/matrix', () => ({
 }));
 vi.mock('$utils/download', async (importOriginal) => ({
   ...(await importOriginal()),
-  saveMediaToGallery: (...args: [string, string, string]) => saveMediaToGallery(...args),
+  saveMediaToGallery: (...args: [Blob | string, string, string]) => saveMediaToGallery(...args),
 }));
 
 vi.mock('file-saver', () => ({
@@ -254,15 +254,19 @@ describe('ImageViewer', () => {
     mockPlatform('android');
     const source = 'https://matrix.example.org/_matrix/client/v1/media/download/example.org/kitten';
     const src = `https://sable-media.localhost/${encodeURIComponent(source)}?__sable_media_cache=3`;
+    const blob = new Blob(['image'], { type: 'image/png' });
     saveMediaToGallery.mockClear();
+    downloadMedia.mockClear();
+    downloadMedia.mockResolvedValue(blob);
 
     renderViewer({ src, info: { mimetype: 'image/png' } });
     fireEvent.contextMenu(screen.getByAltText('kitten.png'));
     fireEvent.click(screen.getByText('Save to Gallery'));
 
     await waitFor(() =>
-      expect(saveMediaToGallery).toHaveBeenCalledWith(source, 'kitten.png', 'image/png')
+      expect(saveMediaToGallery).toHaveBeenCalledWith(blob, 'kitten.png', 'image/png')
     );
+    expect(downloadMedia).toHaveBeenCalledWith(source);
   });
 
   it('labels the primary action Save to Photos on iOS without duplicating it in the overflow menu', () => {
@@ -277,22 +281,20 @@ describe('ImageViewer', () => {
 
   it('routes the primary iOS action for trusted images straight to Photos', async () => {
     mockPlatform('ios');
+    const blob = new Blob(['image'], { type: 'image/png' });
     saveMediaToGallery.mockClear();
     downloadMedia.mockClear();
+    downloadMedia.mockResolvedValue(blob);
     vi.mocked(FileSaver.saveAs).mockClear();
 
     renderViewer({ info: { mimetype: 'image/png' } });
 
     fireEvent.click(screen.getByText('Save to Photos'));
 
     await waitFor(() =>
-      expect(saveMediaToGallery).toHaveBeenCalledWith(
-        'https://example.org/kitten.png',
-        'kitten.png',
-        'image/png'
-      )
+      expect(saveMediaToGallery).toHaveBeenCalledWith(blob, 'kitten.png', 'image/png')
     );
-    expect(downloadMedia).not.toHaveBeenCalled();
+    expect(downloadMedia).toHaveBeenCalledWith('https://example.org/kitten.png');
     expect(FileSaver.saveAs).not.toHaveBeenCalled();
   });
 

src/app/components/image-viewer/ImageViewer.tsx

@@ -156,20 +156,26 @@ export const ImageViewer = as<'div', ImageViewerProps>(
     const downloadFilename = getDownloadFilename(filename, alt, 'image');
     const canSaveToGallery = isAndroidTauri() && (galleryMimeType?.startsWith('image/') ?? false);
 
+    const loadDownloadBlob = () =>
+      getDownloadBlob ? getDownloadBlob() : downloadMedia(getTauriMediaSourceUrl(src) ?? src);
+
+    const saveToGallery = async () => {
+      try {
+        await saveMediaToGallery(await loadDownloadBlob(), downloadFilename, galleryMimeType!);
+      } catch (error) {
+        const message = error instanceof Error ? error.message : 'unknown error';
+        showToast(`Failed to save to gallery: ${message}`);
+      }
+    };
+
     const handleDownload = async () => {
       if (iosSaveToPhotos) {
-        await saveMediaToGallery(
-          getDownloadBlob ? await getDownloadBlob() : src,
-          downloadFilename,
-          galleryMimeType!
-        );
+        await saveToGallery();
         return;
       }
       let fileContent: Blob;
       try {
-        fileContent = await (getDownloadBlob
-          ? getDownloadBlob()
-          : downloadMedia(getTauriMediaSourceUrl(src) ?? src));
+        fileContent = await loadDownloadBlob();
       } catch (error) {
         const message = error instanceof Error ? error.message : 'unknown error';
         showToast(`Failed to download file: ${message}`);
@@ -214,7 +220,7 @@ export const ImageViewer = as<'div', ImageViewerProps>(
     const shareActivation = useMobileTapActivation(isMobile, () => {
       void (async () => {
         try {
-          const blob = await (getDownloadBlob ? getDownloadBlob() : downloadMedia(src));
+          const blob = await loadDownloadBlob();
           const file = new File([blob], downloadFilename, {
             type: blob.type || galleryMimeType || 'application/octet-stream',
           });
@@ -228,7 +234,7 @@ export const ImageViewer = as<'div', ImageViewerProps>(
     });
     const copyImageActivation = useMobileTapActivation(isMobile, () => {
       closeMenu();
-      void (getDownloadBlob ? getDownloadBlob() : downloadMedia(src)).then(copyImageToClipboard);
+      void loadDownloadBlob().then(copyImageToClipboard);
     });
     const pixelatedMenuActivation = useMobileTapActivation(isMobile, () => {
       setIsPixelated(!isPixelated);
@@ -242,13 +248,7 @@ export const ImageViewer = as<'div', ImageViewerProps>(
     const nextActivation = useMobileTapActivation(isMobile, () => onNext?.());
     const galleryActivation = useMobileTapActivation(isMobile, () => {
       closeMenu();
-      void (async () => {
-        await saveMediaToGallery(
-          getDownloadBlob ? await getDownloadBlob() : (getTauriMediaSourceUrl(src) ?? src),
-          downloadFilename,
-          galleryMimeType!
-        );
-      })();
+      void saveToGallery();
     });
     const resetZoomMenuActivation = useMobileTapActivation(isMobile, () => {
       resetTransforms();

src/app/utils/download.test.ts

@@ -23,7 +23,7 @@ const mocks = vi.hoisted(() => ({
   isTauri: vi.fn<() => boolean>(),
   osType: vi.fn<() => string>(),
   showToast: vi.fn<(text: string, durationMs?: number) => void>(),
-  fetch: vi.fn<(input: string) => Promise<Response>>(),
+  fetchMediaBlob: vi.fn<(input: string) => Promise<Blob>>(),
 }));
 const { androidFs, save, writeFile } = mocks;
 
@@ -34,7 +34,7 @@ vi.mock('@tauri-apps/api/core', () => ({
 }));
 vi.mock('@tauri-apps/plugin-os', () => ({ type: mocks.osType }));
 vi.mock('$state/toast', () => ({ showToast: mocks.showToast }));
-vi.mock('$utils/fetch', () => ({ fetch: mocks.fetch }));
+vi.mock('$utils/mediaTransport', () => ({ fetchMediaBlob: mocks.fetchMediaBlob }));
 vi.mock('tauri-plugin-android-fs-api', () => ({
   AndroidFs: mocks.androidFs,
   AndroidPublicGeneralPurposeDir: { Download: 'Download' },
@@ -121,6 +121,22 @@ describe('saveFileToDevice', () => {
     expect(result).toBe('saved');
     expect(FileSaver.saveAs).toHaveBeenCalledWith(expect.any(Blob), 'file.txt');
   });
+
+  it('uses authenticated media transport when saving a URL on Android', async () => {
+    const blob = new Blob(['data'], { type: 'image/png' });
+    mocks.fetchMediaBlob.mockResolvedValue(blob);
+
+    await expect(
+      saveFileToDevice(
+        'https://matrix.example.org/_matrix/client/v1/media/download/example.org/photo',
+        'photo.png'
+      )
+    ).resolves.toBe('saved');
+
+    expect(mocks.fetchMediaBlob).toHaveBeenCalledWith(
+      'https://matrix.example.org/_matrix/client/v1/media/download/example.org/photo'
+    );
+  });
 });
 
 describe('downloadJsonFile', () => {
@@ -171,7 +187,7 @@ describe('saveMediaToGallery', () => {
 
   it('writes all fetched Android image bytes before publishing the gallery file', async () => {
     const bytes = new Uint8Array([0x89, 0x50, 0x4e, 0x47]);
-    mocks.fetch.mockResolvedValueOnce(new Response(bytes, { status: 200 }));
+    mocks.fetchMediaBlob.mockResolvedValueOnce(new Blob([bytes]));
 
     await saveMediaToGallery('https://matrix.example.org/photo', 'photo.png', 'image/png');
 
@@ -180,6 +196,7 @@ describe('saveMediaToGallery', () => {
       androidFs.setPublicFilePending.mock.invocationCallOrder[0]!
     );
     expect(androidFs.setPublicFilePending).toHaveBeenCalledWith('content://media/image', false);
+    expect(mocks.fetchMediaBlob).toHaveBeenCalledWith('https://matrix.example.org/photo');
   });
 
   it('does not create a gallery file when Android storage permission is denied', async () => {
@@ -288,7 +305,7 @@ describe('saveMediaToGallery', () => {
   });
 
   it('shows exactly one gallery failure toast when fetching the media fails on Android', async () => {
-    mocks.fetch.mockRejectedValueOnce(new Error('network down'));
+    mocks.fetchMediaBlob.mockRejectedValueOnce(new Error('network down'));
 
     await saveMediaToGallery('mxc://example/photo.png', 'photo.png', 'image/png');
 
@@ -301,9 +318,7 @@ describe('saveMediaToGallery', () => {
   });
 
   it('does not save an HTTP error response as an Android gallery image', async () => {
-    mocks.fetch.mockResolvedValueOnce(
-      new Response('not found', { status: 404, statusText: 'Not Found' })
-    );
+    mocks.fetchMediaBlob.mockRejectedValueOnce(new Error('Failed to fetch media: 404 Not Found'));
 
     await saveMediaToGallery('mxc://example/missing.png', 'missing.png', 'image/png');
 
@@ -317,10 +332,7 @@ describe('saveMediaToGallery', () => {
 
   it('shows exactly one photos failure toast when blob conversion fails on iOS', async () => {
     vi.mocked(osType).mockReturnValue('ios');
-    mocks.fetch.mockResolvedValueOnce({
-      ok: true,
-      blob: () => Promise.reject(new Error('decode failed')),
-    } as unknown as Response);
+    mocks.fetchMediaBlob.mockRejectedValueOnce(new Error('decode failed'));
 
     await saveMediaToGallery('mxc://example/photo.png', 'photo.png', 'image/png');
 

src/app/utils/download.ts

@@ -1,8 +1,9 @@
 import FileSaver from 'file-saver';
 import { invoke, isTauri } from '@tauri-apps/api/core';
 import { type as osType } from '@tauri-apps/plugin-os';
-import { fetch } from '$utils/fetch';
 import { showToast } from '$state/toast';
+import { fetchMediaBlob } from '$utils/mediaTransport';
+import { getTauriMediaSourceUrl } from '$utils/mediaUrl';
 
 const INVALID_FILENAME_CHARS = /[<>:"/\\|?*]/g;
 const CONTROL_CHARS = /\p{Cc}/gu;
@@ -53,11 +54,7 @@ export const getDownloadFilename = (
 
 async function resolveBlob(input: Blob | string): Promise<Blob> {
   if (typeof input !== 'string') return input;
-  const response = await fetch(input);
-  if (!response.ok) {
-    throw new Error(`Failed to fetch media: ${response.status} ${response.statusText}`);
-  }
-  return response.blob();
+  return fetchMediaBlob(getTauriMediaSourceUrl(input) ?? input);
 }
 
 export async function saveMediaToGallery(