From 74f2d92c69f14c07e41742cf3bd8bcbf44317f40 Mon Sep 17 00:00:00 2001
From: Chew Tee Ming <chew.tee.ming@nindatech.com>
Date: Tue, 21 Jan 2025 14:50:23 +0800
Subject: [PATCH 1/3] fix

---
 packages/kit/src/runtime/client/utils.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/packages/kit/src/runtime/client/utils.js b/packages/kit/src/runtime/client/utils.js
index 28a06d862489..3e121a75e47a 100644
--- a/packages/kit/src/runtime/client/utils.js
+++ b/packages/kit/src/runtime/client/utils.js
@@ -130,6 +130,12 @@ export function get_link_info(a, base, uses_hash_router) {
 
 	try {
 		url = new URL(a instanceof SVGAElement ? a.href.baseVal : a.href, document.baseURI);
+
+		// if the hash doesn't start with `#/` then it's probably linking to an id on the current page
+		if (uses_hash_router && url.hash.match(/^#[^/]/)) {
+			const route = location.hash.split('#')[1] || '/';
+			url.hash = `#${route}${url.hash}`;
+		}
 	} catch {}
 
 	const target = a instanceof SVGAElement ? a.target.baseVal : a.target;

From 0bdc243db26edcbfde21e46f5856f97303ba6363 Mon Sep 17 00:00:00 2001
From: Chew Tee Ming <chew.tee.ming@nindatech.com>
Date: Tue, 21 Jan 2025 14:50:25 +0800
Subject: [PATCH 2/3] test

---
 .../hash-based-routing/src/routes/anchor/+page.svelte    | 3 +++
 packages/kit/test/apps/hash-based-routing/test/test.js   | 9 +++++++++
 2 files changed, 12 insertions(+)
 create mode 100644 packages/kit/test/apps/hash-based-routing/src/routes/anchor/+page.svelte

diff --git a/packages/kit/test/apps/hash-based-routing/src/routes/anchor/+page.svelte b/packages/kit/test/apps/hash-based-routing/src/routes/anchor/+page.svelte
new file mode 100644
index 000000000000..3be87857c826
--- /dev/null
+++ b/packages/kit/test/apps/hash-based-routing/src/routes/anchor/+page.svelte
@@ -0,0 +1,3 @@
+<a href="#test">go to #test</a>
+
+<p id="test">#test</p>
diff --git a/packages/kit/test/apps/hash-based-routing/test/test.js b/packages/kit/test/apps/hash-based-routing/test/test.js
index 23666ed5e562..d7962d380ea4 100644
--- a/packages/kit/test/apps/hash-based-routing/test/test.js
+++ b/packages/kit/test/apps/hash-based-routing/test/test.js
@@ -89,4 +89,13 @@ test.describe('hash based navigation', () => {
 		url = new URL(page.url());
 		expect(url.hash).toBe('#/reroute-b');
 	});
+
+	test('relative anchor works', async ({ page }) => {
+		await page.goto('/#/anchor');
+
+		await page.locator('a[href="#test"]').click();
+		await expect(page.locator('#test')).toHaveText('#test');
+		const url = new URL(page.url());
+		expect(url.hash).toBe('#/anchor#test');
+	});
 });

From 0706244f2df387176b1e65d79a8e4e8be88e1d77 Mon Sep 17 00:00:00 2001
From: Chew Tee Ming <chew.tee.ming@nindatech.com>
Date: Tue, 21 Jan 2025 14:52:23 +0800
Subject: [PATCH 3/3] changeset

---
 .changeset/forty-houses-collect.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/forty-houses-collect.md

diff --git a/.changeset/forty-houses-collect.md b/.changeset/forty-houses-collect.md
new file mode 100644
index 000000000000..6a48772b3742
--- /dev/null
+++ b/.changeset/forty-houses-collect.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: correctly handle relative anchors when using the hash router