From 510904b7a89af5a9d1745c6b109742d09f90dd24 Mon Sep 17 00:00:00 2001
From: RaphaelFakhri <153192858+RaphaelFakhri@users.noreply.github.com>
Date: Sat, 24 Oct 2026 17:51:56 +0000
Subject: [PATCH] fix(platform-redirect): Keep the anchor of the next path

PlatformLink encodes its target, so a link such as
/configuration/options/#ignoreErrors reaches /platform-redirect as
next=%2Fconfiguration%2Foptions%2F%23ignoreErrors. sanitizeNext only
keeps the path, so the redirect and the platform list dropped the
anchor and readers landed at the top of the page.

Add sanitizeNextHash, which returns the fragment limited to id
characters, and append it to the redirect and platform list URLs.
---
 app/platform-redirect/page.tsx      |  7 +++---
 app/platform-redirect/utils.spec.ts | 34 ++++++++++++++++++++++++++++-
 app/platform-redirect/utils.ts      | 22 +++++++++++++++++++
 3 files changed, 59 insertions(+), 4 deletions(-)

diff --git a/app/platform-redirect/page.tsx b/app/platform-redirect/page.tsx
index c1158ad278488..fa32a468249ee 100644
--- a/app/platform-redirect/page.tsx
+++ b/app/platform-redirect/page.tsx
@@ -7,7 +7,7 @@ import {SmartLink} from 'sentry-docs/components/smartLink';
 import {extractPlatforms, getDocsRootNode, nodeForPath} from 'sentry-docs/docTree';
 import {setServerContext} from 'sentry-docs/serverContext';
 
-import {sanitizeNext} from './utils';
+import {sanitizeNext, sanitizeNextHash} from './utils';
 
 export const metadata: Metadata = {
   robots: 'noindex',
@@ -29,6 +29,7 @@ export default async function Page(props: {
   }
 
   const pathname = sanitizeNext(next);
+  const hash = sanitizeNextHash(next);
   const isTracingAutomatedInstrumentation =
     pathname.replace(/\/$/, '') === '/tracing/instrumentation/automatic-instrumentation';
   const rootNode = await getDocsRootNode();
@@ -145,7 +146,7 @@ export default async function Page(props: {
       p => p.key === requestedPlatform?.toLowerCase()
     );
     if (validPlatform) {
-      return redirect(`${validPlatform.url}${pathname}`);
+      return redirect(`${validPlatform.url}${pathname}${hash}`);
     }
   }
 
@@ -167,7 +168,7 @@ export default async function Page(props: {
       <ul>
         {platformOrGuideList.map(p => (
           <li key={p.key} style={{marginLeft: p.shouldBeNested ? '20px' : '0'}}>
-            <SmartLink to={`${p.url}${pathname}`}>
+            <SmartLink to={`${p.url}${pathname}${hash}`}>
               <PlatformIcon
                 size={16}
                 platform={p.icon}
diff --git a/app/platform-redirect/utils.spec.ts b/app/platform-redirect/utils.spec.ts
index 3f315d7f62bf5..f82ed30ba082e 100644
--- a/app/platform-redirect/utils.spec.ts
+++ b/app/platform-redirect/utils.spec.ts
@@ -1,6 +1,6 @@
 import {describe, expect, it} from 'vitest';
 
-import {sanitizeNext} from './utils';
+import {sanitizeNext, sanitizeNextHash} from './utils';
 
 describe('sanitizeNext', () => {
   it('should return an empty string for external URLs', () => {
@@ -83,3 +83,35 @@ describe('sanitizeNext', () => {
     expect(sanitizeNext(input)).toBe(expectedOutput);
   });
 });
+
+describe('sanitizeNextHash', () => {
+  it('should return an empty string when there is no fragment', () => {
+    expect(sanitizeNextHash('/configuration/options/')).toBe('');
+    expect(sanitizeNextHash('/configuration/options/#')).toBe('');
+  });
+
+  it('should keep the fragment of an encoded next path', () => {
+    // `PlatformLink` encodes `next`, so the `#` arrives as `%23`
+    expect(sanitizeNextHash('%2Fconfiguration%2Foptions%2F%23ignoreErrors')).toBe(
+      '#ignoreErrors'
+    );
+    expect(sanitizeNextHash('/configuration/options/#tracing-options')).toBe(
+      '#tracing-options'
+    );
+  });
+
+  it('should keep dots and underscores used in option ids', () => {
+    expect(sanitizeNextHash('/configuration/options/#godot_logger.event_mask')).toBe(
+      '#godot_logger.event_mask'
+    );
+  });
+
+  it('should remove unsafe characters from the fragment', () => {
+    expect(sanitizeNextHash('/path/#a"><script>b')).toBe('#ascriptb');
+    expect(sanitizeNextHash('/path/#a/b?c=1')).toBe('#abc1');
+  });
+
+  it('should return an empty string for a malformed URI component', () => {
+    expect(sanitizeNextHash('/path/#%E0%A4%A')).toBe('');
+  });
+});
diff --git a/app/platform-redirect/utils.ts b/app/platform-redirect/utils.ts
index 8148cf56956a1..500bfa9f63894 100644
--- a/app/platform-redirect/utils.ts
+++ b/app/platform-redirect/utils.ts
@@ -35,3 +35,25 @@ export const sanitizeNext = (next: string) => {
 
   return pathname === '/' ? '' : pathname;
 };
+
+/**
+ * Returns the `#fragment` of `next` so the redirect can land on the same section,
+ * or an empty string if there is none. Only characters used in heading and option
+ * ids are kept.
+ */
+export const sanitizeNextHash = (next: string) => {
+  let decoded: string;
+  try {
+    decoded = decodeURIComponent(next);
+  } catch {
+    return '';
+  }
+
+  const hashIndex = decoded.indexOf('#');
+  if (hashIndex === -1) {
+    return '';
+  }
+
+  const fragment = decoded.slice(hashIndex + 1).replace(/[^\w\-.]/g, '');
+  return fragment ? `#${fragment}` : '';
+};