fix: decode hash when clicking on same hash to correctly scroll on non ascii hashes

.changeset/smooth-dogs-travel.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: decode non ASCII anchor hashes when scrolling into view

packages/kit/src/runtime/client/client.js

@@ -2093,7 +2093,7 @@ function _start_router() {
 				if (hash === '' || (hash === 'top' && a.ownerDocument.getElementById('top') === null)) {
 					window.scrollTo({ top: 0 });
 				} else {
-					a.ownerDocument.getElementById(hash)?.scrollIntoView();
+					a.ownerDocument.getElementById(decodeURIComponent(hash))?.scrollIntoView();
 				}
 
 				return;

packages/kit/test/apps/basics/src/routes/anchor/anchor/+page.svelte

@@ -8,3 +8,4 @@
 <div style="height: 180vh; background-color: honeydew;">
 	<p id="go-to-.=" class="special-char-id">The browser scrolls to me</p>
 </div>
+<a id="non-ascii-anchor" href="#go-to-encöded">Anchor demo (non-ASCII)</a>

packages/kit/test/apps/basics/test/cross-platform/client.test.js

@@ -9,7 +9,7 @@
 test.describe.configure({ mode: 'parallel' });
 
 test.describe('a11y', () => {
 	test('resets focus', async ({ page, clicknav, browserName }) => {
 		const tab = browserName === 'webkit' ? 'Alt+Tab' : 'Tab';
 
 		await page.goto('/accessibility/a');
@@ -33,7 +33,7 @@
 		expect(await page.evaluate(() => document.documentElement.getAttribute('tabindex'))).toBe(null);
 	});
 
 	test('applies autofocus after a navigation', async ({ page, clicknav }) => {
 		await page.goto('/accessibility/autofocus/a');
 
 		await clicknav('[href="/accessibility/autofocus/b"]');
@@ -280,6 +280,20 @@
 		expect(await in_view('#go-to-encöded')).toBe(true);
 	});
 
+	test('url-supplied non-ascii anchor works on navigation to page after manual scroll', async ({
+		page,
+		in_view,
+		clicknav
+	}) => {
+		await page.goto('/anchor');
+		await clicknav('#non-ascii-anchor');
+		await page.evaluate(() => {
+			window.scrollTo(0, 50);
+		});
+		await page.locator('#non-ascii-anchor').click();
+		expect(await in_view('#go-to-encöded')).toBe(true);
+	});
+
 	test('url-supplied anchor with special characters works on navigation to page', async ({
 		page,
 		in_view,
@@ -782,7 +796,7 @@
 	test('trailing slash redirect', async ({ page, clicknav }) => {
 		await page.goto('/routing/trailing-slash');
 
 		await clicknav('a[href="/routing/trailing-slash/always"]');
 		expect(new URL(page.url()).pathname).toBe('/routing/trailing-slash/always/');
 		await expect(page.locator('p')).toHaveText('/routing/trailing-slash/always/');
 
@@ -796,7 +810,7 @@
 	});
 
 	test('trailing slash redirect works when navigating from root page', async ({
 		page,
 		clicknav
 	}) => {
 		await page.goto('/');