fix(frontend): prevent duplicate subdirectory prefix in dashboard fullscreen and saved queries navigation

React Router v5 prepends its basename automatically on history.push/replace
and <Link to>. Passing a path already prefixed by applicationRoot() doubled
the subdirectory on deployments using SUPERSET_APP_ROOT.

- Dashboard fullscreen toggle (sc-103933): switch from window.location.pathname
  to useLocation().pathname so history.replace receives a router-relative path
- Saved Queries "+ Query" / label links (sc-103661): remove makeUrl() from
  history.push and <Link to>; retain makeUrl() for window.open and clipboard
  where the full browser-absolute path is required

Adds unit tests (Header.test.tsx, SavedQueryList.test.tsx) and Playwright E2E
specs (fullscreen.spec.ts, saved-queries.spec.ts) covering both fixes.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

superset-frontend/playwright/tests/dashboard/fullscreen.spec.ts

@@ -0,0 +1,117 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/**
+ * Fullscreen toggle E2E tests.
+ *
+ * Regression tests for subdirectory deployments: when Superset runs at a path
+ * prefix (e.g. /pcs), the fullscreen toggle must not duplicate the prefix in
+ * the URL (sc-103933).
+ */
+
+import { testWithAssets as test, expect } from '../../helpers/fixtures';
+import { DashboardPage } from '../../pages/DashboardPage';
+import { apiPostDashboard } from '../../helpers/api/dashboard';
+import { TIMEOUT } from '../../utils/constants';
+
+test('toggling fullscreen adds standalone param without duplicating path segments', async ({
+  page,
+  testAssets,
+}) => {
+  test.setTimeout(TIMEOUT.SLOW_TEST);
+
+  // Create a minimal dashboard to test against
+  const dashboardResponse = await apiPostDashboard(page, {
+    dashboard_title: `test_fullscreen_${Date.now()}`,
+    published: true,
+  });
+  expect(dashboardResponse.status()).toBe(201);
+  const { id: dashboardId } = await dashboardResponse.json();
+  testAssets.trackDashboard(dashboardId);
+
+  const dashboardPage = new DashboardPage(page);
+  await dashboardPage.gotoById(dashboardId);
+  await dashboardPage.waitForLoad();
+
+  // Record the pathname before toggling (should be something like /superset/dashboard/N/)
+  const pathBefore = new URL(page.url()).pathname;
+
+  // Open the three-dot menu and click "Enter fullscreen"
+  await dashboardPage.openHeaderActionsMenu();
+  await page.getByText('Enter fullscreen').click();
+
+  // Wait for the URL to update with standalone param
+  await page.waitForURL(/standalone=1/, { timeout: TIMEOUT.API_RESPONSE });
+
+  const urlAfter = new URL(page.url());
+
+  // The pathname must not have grown — i.e. no segment was duplicated
+  expect(urlAfter.pathname).toBe(pathBefore);
+
+  // standalone=1 must be present
+  expect(urlAfter.searchParams.get('standalone')).toBe('1');
+
+  // The dashboard header must still be visible (not a blank page)
+  await expect(
+    page.locator('[data-test="dashboard-header-container"]'),
+  ).toBeVisible();
+});
+
+test('toggling fullscreen off removes standalone param without duplicating path segments', async ({
+  page,
+  testAssets,
+}) => {
+  test.setTimeout(TIMEOUT.SLOW_TEST);
+
+  const dashboardResponse = await apiPostDashboard(page, {
+    dashboard_title: `test_fullscreen_exit_${Date.now()}`,
+    published: true,
+  });
+  expect(dashboardResponse.status()).toBe(201);
+  const { id: dashboardId } = await dashboardResponse.json();
+  testAssets.trackDashboard(dashboardId);
+
+  const dashboardPage = new DashboardPage(page);
+  // Navigate directly into fullscreen mode
+  await page.goto(`superset/dashboard/${dashboardId}/?standalone=1`);
+  await dashboardPage.waitForLoad();
+
+  const pathBefore = new URL(page.url()).pathname;
+
+  // Open the three-dot menu and click "Exit fullscreen"
+  await dashboardPage.openHeaderActionsMenu();
+  await page.getByText('Exit fullscreen').click();
+
+  // Wait for standalone param to disappear
+  await page.waitForFunction(
+    () => !new URL(window.location.href).searchParams.has('standalone'),
+    { timeout: TIMEOUT.API_RESPONSE },
+  );
+
+  const urlAfter = new URL(page.url());
+
+  // Pathname must be unchanged — no duplicated segment
+  expect(urlAfter.pathname).toBe(pathBefore);
+  expect(urlAfter.searchParams.get('standalone')).toBeNull();
+
+  // Dashboard must still be rendered
+  await expect(
+    page.locator('[data-test="dashboard-header-container"]'),
+  ).toBeVisible();
+});

superset-frontend/playwright/tests/sqllab/saved-queries.spec.ts

@@ -0,0 +1,59 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/**
+ * Saved Queries list E2E tests.
+ *
+ * Regression tests for subdirectory deployments: "+ Query" and query label
+ * links must navigate to SQL Lab without duplicating the path prefix (sc-103661).
+ */
+
+import { test, expect } from '@playwright/test';
+import { URL as APP_URLS } from '../../utils/urls';
+import { TIMEOUT } from '../../utils/constants';
+
+test('+ Query button navigates to SQL Lab without duplicating path segments', async ({
+  page,
+}) => {
+  test.setTimeout(TIMEOUT.SLOW_TEST);
+
+  await page.goto(APP_URLS.SAVED_QUERIES_LIST);
+
+  // Wait for the list to load
+  await page.waitForSelector('[data-test="saved_query-list-view"]', {
+    timeout: TIMEOUT.PAGE_LOAD,
+  });
+
+  // Click the "+ Query" button in the submenu (accessible name is "plus Query" due to icon)
+  await page.getByRole('button', { name: /Query/i }).click();
+
+  // Wait for SQL Lab to load
+  await page.waitForURL(/sqllab/, { timeout: TIMEOUT.PAGE_LOAD });
+
+  const url = new URL(page.url());
+
+  // No path segment should appear twice consecutively — catches the double-prefix bug
+  // where React Router prepends the basename a second time (e.g. /superset/superset/sqllab).
+  expect(url.pathname).not.toMatch(/\/(\w+)\/\1\//);
+
+  // SQL Lab editor must be visible (not a blank page)
+  await expect(page.locator('[data-test="sql-editor-tabs"]')).toBeVisible({
+    timeout: TIMEOUT.PAGE_LOAD,
+  });
+});

superset-frontend/src/dashboard/components/Header/Header.test.tsx

@@ -31,6 +31,20 @@ import { DASHBOARD_HEADER_ID } from '../../util/constants';
 import { UPDATE_COMPONENTS } from '../../actions/dashboardLayout';
 import { AutoRefreshStatus } from '../../types/autoRefresh';
 
+const mockHistoryReplace = jest.fn();
+jest.mock('react-router-dom', () => ({
+  ...jest.requireActual('react-router-dom'),
+  useHistory: () => ({
+    replace: mockHistoryReplace,
+  }),
+  useLocation: jest.fn(() => ({
+    pathname: '/dashboard',
+    search: '?standalone=1',
+    hash: '',
+    state: undefined,
+  })),
+}));
+
 const initialState = {
   dashboardInfo: {
     id: 1,
@@ -223,6 +237,13 @@ beforeAll(() => {
 
 beforeEach(() => {
   jest.clearAllMocks();
+  const { useLocation } = jest.requireMock('react-router-dom');
+  useLocation.mockReturnValue({
+    pathname: '/dashboard',
+    search: '?standalone=1',
+    hash: '',
+    state: undefined,
+  });
 
   (useUnsavedChangesPrompt as jest.Mock).mockReturnValue({
     showModal: false,
@@ -968,3 +989,30 @@ test('should sync theme ref when navigating between dashboards', async () => {
     expect(setUnsavedChanges).toHaveBeenCalledTimes(0);
   });
 });
+
+test('should not duplicate subdirectory prefix when toggling fullscreen', async () => {
+  const { useLocation } = jest.requireMock('react-router-dom');
+  // Simulate React Router with basename=/pcs: useLocation returns path relative to basename
+  useLocation.mockReturnValue({
+    pathname: '/dashboard',
+    search: '?standalone=1',
+    hash: '',
+    state: undefined,
+  });
+  // Simulate browser URL including the subdirectory prefix
+  window.history.pushState({}, 'Test page', '/pcs/dashboard?standalone=1');
+
+  setup();
+  await openActionsDropdown();
+  userEvent.click(screen.getByText('Exit fullscreen'));
+
+  // history.replace must be called with the Router-relative path, not window.location.pathname.
+  // If the subdirectory prefix (/pcs) were included, React Router would prepend it again,
+  // producing /pcs/pcs/dashboard (the bug). The path must start with /dashboard, not /pcs/.
+  expect(mockHistoryReplace).toHaveBeenCalledWith(
+    expect.not.stringMatching(/^\/pcs\//),
+  );
+  expect(mockHistoryReplace).toHaveBeenCalledWith(
+    expect.stringMatching(/^\/dashboard(\?|$)/),
+  );
+});

superset-frontend/src/dashboard/components/Header/useHeaderActionsDropdownMenu.tsx

@@ -19,7 +19,7 @@
 import type { Dispatch, ReactElement, SetStateAction } from 'react';
 import { useState, useEffect, useCallback, useMemo } from 'react';
 import { useSelector } from 'react-redux';
-import { useHistory } from 'react-router-dom';
+import { useHistory, useLocation } from 'react-router-dom';
 import { Menu, MenuItem } from '@superset-ui/core/components/Menu';
 import { t } from '@apache-superset/core/translation';
 import { isEmpty } from 'lodash';
@@ -75,6 +75,7 @@ export const useHeaderActionsMenu = ({
   const [isDropdownVisible, setIsDropdownVisible] = useState(false);
   const { canExportImage } = usePermissions();
   const history = useHistory();
+  const location = useLocation();
   const directPathToChild = useSelector(
     (state: RootState) => state.dashboardState.directPathToChild,
   );
@@ -101,8 +102,11 @@ export const useHeaderActionsMenu = ({
         case MenuKeys.ToggleFullscreen: {
           const isCurrentlyStandalone =
             Number(getUrlParam(URL_PARAMS.standalone)) === 1;
+          // Use location.pathname from React Router (relative to basename) rather than
+          // window.location.pathname to avoid duplicating the subdirectory prefix when
+          // history.replace prepends it again.
           const url = getDashboardUrl({
-            pathname: window.location.pathname,
+            pathname: location.pathname,
             filters: getActiveFilters(),
             hash: window.location.hash,
             standalone: isCurrentlyStandalone ? null : 1,
@@ -125,6 +129,7 @@ export const useHeaderActionsMenu = ({
       showRefreshModal,
       manageEmbedded,
       history,
+      location,
     ],
   );
 
@@ -133,6 +138,10 @@ export const useHeaderActionsMenu = ({
     [dashboardTitle],
   );
 
+  // window.location.pathname is intentional here: this URL is used for sharing
+  // (email, embed, copy link) and must be a full browser-absolute path that
+  // includes the application root. Do NOT replace with useLocation().pathname —
+  // that would strip the subdirectory prefix and produce a broken share link.
   const url = useMemo(
     () =>
       getDashboardUrl({

superset-frontend/src/pages/SavedQueryList/SavedQueryList.test.tsx

@@ -25,11 +25,20 @@ import {
   fireEvent,
   waitFor,
 } from 'spec/helpers/testing-library';
-import { MemoryRouter } from 'react-router-dom';
+import { createMemoryHistory } from 'history';
+import { MemoryRouter, Router } from 'react-router-dom';
 import { QueryParamProvider } from 'use-query-params';
 import { ReactRouter5Adapter } from 'use-query-params/adapters/react-router-5';
 import SavedQueryList from '.';
 
+jest.mock('src/utils/getBootstrapData', () => ({
+  __esModule: true,
+  default: jest.requireActual('src/utils/getBootstrapData').default,
+  applicationRoot: jest.fn(() => '/superset'),
+  staticAssetsPrefix: jest.requireActual('src/utils/getBootstrapData')
+    .staticAssetsPrefix,
+}));
+
 // Increase default timeout
 jest.setTimeout(30000);
 
@@ -102,6 +111,30 @@ const renderList = (props = {}, storeOverrides = {}) =>
     },
   );
 
+// Renders with a real memory history so we can spy on push/replace without
+// breaking use-query-params (which needs a real location from router context).
+const renderListWithHistory = (props = {}, storeOverrides = {}) => {
+  const history = createMemoryHistory();
+  const result = render(
+    <Router history={history}>
+      <QueryParamProvider adapter={ReactRouter5Adapter}>
+        <SavedQueryList user={mockUser} {...props} />
+      </QueryParamProvider>
+    </Router>,
+    {
+      useRedux: true,
+      store: configureStore([thunk])({
+        user: {
+          ...mockUser,
+          roles: { Admin: [['can_write', 'SavedQuery']] },
+        },
+        ...storeOverrides,
+      }),
+    },
+  );
+  return { ...result, history };
+};
+
 // eslint-disable-next-line no-restricted-globals -- TODO: Migrate from describe blocks
 describe('SavedQueryList', () => {
   beforeEach(() => {
@@ -212,6 +245,60 @@ describe('SavedQueryList', () => {
     });
   });
 
+  test('window.open for "open in new tab" retains the subdirectory prefix', async () => {
+    // When a query row is Cmd/Ctrl-clicked the component calls
+    // window.open(makeUrl(...)) — the full application-root-prefixed URL is needed
+    // because window.open operates in browser URL space, not React Router namespace.
+    // This test guards against accidentally removing makeUrl from the window.open call.
+    const mockWindowOpen = jest
+      .spyOn(window, 'open')
+      .mockImplementation(() => null);
+
+    renderList();
+    await screen.findByTestId('saved_query-list-view');
+    await screen.findByText(mockQueries[0].label);
+
+    const editButtons = await screen.findAllByTestId('edit-action');
+    fireEvent.click(editButtons[0], { metaKey: true });
+
+    expect(mockWindowOpen).toHaveBeenCalledWith(
+      expect.stringContaining('/superset/sqllab'),
+    );
+    mockWindowOpen.mockRestore();
+  });
+
+  test('+ Query button navigates without duplicating subdirectory prefix', async () => {
+    // applicationRoot is mocked to /superset. Without the fix, history.push would
+    // receive /superset/sqllab?new=true, and React Router would prepend /superset
+    // again, producing /superset/superset/sqllab?new=true.
+    const { history } = renderListWithHistory();
+    const pushSpy = jest.spyOn(history, 'push');
+    await screen.findByTestId('saved_query-list-view');
+
+    const queryButton = await screen.findByRole('button', { name: /query/i });
+    fireEvent.click(queryButton);
+
+    expect(pushSpy).toHaveBeenCalledWith('/sqllab?new=true');
+    expect(pushSpy).not.toHaveBeenCalledWith(
+      expect.stringContaining('/superset/sqllab'),
+    );
+  });
+
+  test('query label links do not include subdirectory prefix', async () => {
+    // <Link to> in React Router resolves relative to the basename, so passing
+    // makeUrl('/sqllab?savedQueryId=0') would produce /superset/superset/sqllab.
+    renderListWithHistory();
+    await screen.findByTestId('saved_query-list-view');
+    await screen.findByText(mockQueries[0].label);
+
+    const queryLink = screen.getByRole('link', { name: mockQueries[0].label });
+    expect(queryLink).toHaveAttribute('href', '/sqllab?savedQueryId=0');
+    expect(queryLink).not.toHaveAttribute(
+      'href',
+      expect.stringContaining('/superset/sqllab'),
+    );
+  });
+
   test('shows/hides elements based on permissions', async () => {
     // Mock info response without write permission
     fetchMock.removeRoute(queriesInfoEndpoint);

superset-frontend/src/pages/SavedQueryList/index.tsx

@@ -223,7 +223,7 @@ function SavedQueryList({
     name: t('Query'),
     buttonStyle: 'primary',
     onClick: () => {
-      history.push(makeUrl('/sqllab?new=true'));
+      history.push('/sqllab?new=true');
     },
   });
 
@@ -231,6 +231,10 @@ function SavedQueryList({
 
   // Action methods
   const openInSqlLab = (id: number, openInNewWindow: boolean) => {
+    // makeUrl is correct here: clipboard and window.open operate in browser URL
+    // space and need the full application-root-prefixed path. Do NOT use makeUrl
+    // for history.push or <Link to> — React Router prepends the basename itself,
+    // which would double the subdirectory prefix.
     copyTextToClipboard(() =>
       Promise.resolve(
         `${window.location.origin}${makeUrl(`/sqllab?savedQueryId=${id}`)}`,
@@ -245,7 +249,8 @@ function SavedQueryList({
     if (openInNewWindow) {
       window.open(makeUrl(`/sqllab?savedQueryId=${id}`));
     } else {
-      history.push(makeUrl(`/sqllab?savedQueryId=${id}`));
+      // Router-relative path (no makeUrl): React Router prepends the basename.
+      history.push(`/sqllab?savedQueryId=${id}`);
     }
   };
 
@@ -338,9 +343,7 @@ function SavedQueryList({
           row: {
             original: { id, label },
           },
-        }: any) => (
-          <Link to={makeUrl(`/sqllab?savedQueryId=${id}`)}>{label}</Link>
-        ),
+        }: any) => <Link to={`/sqllab?savedQueryId=${id}`}>{label}</Link>,
         id: 'label',
       },
       {