From e2d58380a766cb455e88c3c8f442be66e59482cc Mon Sep 17 00:00:00 2001
From: FloPinguin <25036848+FloPinguin@users.noreply.github.com>
Date: Tue, 24 Mar 2026 20:21:13 +0100
Subject: [PATCH] =?UTF-8?q?For=20v30:=20Fix=20base=20language=20preferred?=
 =?UTF-8?q?=20over=20regional=20variant=20in=20auto-detection=20?=
 =?UTF-8?q?=F0=9F=8C=90=20(#3506)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

## Description:

When the browser reports a locale like `de-DE`, the language selector
didn't find an exact match and fell through to candidate matching, where
it picked `de-CH` (Swiss German) over `de` (German) because longer codes
were sorted first.

This adds an early check: if the base language code (e.g. `de`) is
directly supported, return it immediately before scanning regional
candidates.

FYI @Aotumuri

## Please complete the following:

- [X] I have added screenshots for all UI updates
- [X] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [X] I have added relevant tests to the test directory
- [X] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

FloPinguin
---
 src/client/LangSelector.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/client/LangSelector.ts b/src/client/LangSelector.ts
index a373a73ce..479b2d012 100644
--- a/src/client/LangSelector.ts
+++ b/src/client/LangSelector.ts
@@ -72,6 +72,7 @@ export class LangSelector extends LitElement {
     if (supported.has(lang)) return lang;
 
     const base = lang.slice(0, 2);
+    if (supported.has(base)) return base;
     const candidates = Array.from(supported).filter((key) =>
       key.startsWith(base),
     );