Desktop: Fixes #9070: Fix external links in PDFs break Joplin (#9094)

packages/app-desktop/ElectronAppWrapper.ts

@@ -4,6 +4,7 @@ import shim from '@joplin/lib/shim';
 import { isCallbackUrl } from '@joplin/lib/callbackUrlUtils';
 
 import { BrowserWindow, Tray, screen } from 'electron';
+import bridge from './bridge';
 const url = require('url');
 const path = require('path');
 const { dirname } = require('@joplin/lib/path-utils');
@@ -142,6 +143,15 @@ export default class ElectronAppWrapper {
 			}, 3000);
 		}
 
+		// will-frame-navigate is fired by clicking on a link within the BrowserWindow.
+		this.win_.webContents.on('will-frame-navigate', event => {
+			// If the link changes the URL of the browser window,
+			if (event.isMainFrame) {
+				event.preventDefault();
+				void bridge().openExternal(event.url);
+			}
+		});
+
 		this.win_.on('close', (event: any) => {
 			// If it's on macOS, the app is completely closed only if the user chooses to close the app (willQuitApp_ will be true)
 			// otherwise the window is simply hidden, and will be re-open once the app is "activated" (which happens when the

packages/app-desktop/integration-tests/main.spec.ts

@@ -76,4 +76,49 @@ test.describe('main', () => {
 
 		await expect(mainScreen.noteListContainer.locator('[title^="Toggle sort order"]')).not.toBeVisible();
 	});
+
+	test('clicking on an external link should try to launch a browser', async ({ electronApp, mainWindow }) => {
+		const mainScreen = new MainScreen(mainWindow);
+		await mainScreen.waitFor();
+
+		// Mock openExternal
+		const nextExternalUrlPromise = electronApp.evaluate(({ shell }) => {
+			return new Promise<string>(resolve => {
+				const openExternal = async (url: string) => {
+					resolve(url);
+				};
+				shell.openExternal = openExternal;
+			});
+		});
+
+		// Create a test link
+		const testLinkTitle = 'This is a test link!';
+		const linkHref = 'https://joplinapp.org/';
+
+		await mainWindow.evaluate(({ testLinkTitle, linkHref }) => {
+			const testLink = document.createElement('a');
+			testLink.textContent = testLinkTitle;
+			testLink.onclick = () => {
+				// We need to navigate by setting location.href -- clicking on a link
+				// directly within the main window (i.e. not in a PDF viewer) doesn't
+				// navigate.
+				location.href = linkHref;
+			};
+			testLink.href = '#';
+
+			// Display on top of everything
+			testLink.style.zIndex = '99999';
+			testLink.style.position = 'fixed';
+			testLink.style.top = '0';
+			testLink.style.left = '0';
+
+			document.body.appendChild(testLink);
+		}, { testLinkTitle, linkHref });
+
+		const testLink = mainWindow.getByText(testLinkTitle);
+		await expect(testLink).toBeVisible();
+		await testLink.click({ noWaitAfter: true });
+
+		expect(await nextExternalUrlPromise).toBe(linkHref);
+	});
 });

packages/app-desktop/main-html.js

@@ -31,12 +31,6 @@ const React = require('react');
 const nodeSqlite = require('sqlite3');
 const initLib = require('@joplin/lib/initLib').default;
 
-// Security: If we attempt to navigate away from the root HTML page, it's likely because
-// of an improperly sanitized link. Prevent this by closing the window before we can
-// navigate away.
-window.onbeforeunload = () => {
-	window.close();
-};
 
 if (bridge().env() === 'dev') {
 	const newConsole = function(oldConsole) {