From 742a02c5cf59477b90ab7d2e004c89cdbc4f67de Mon Sep 17 00:00:00 2001
From: schroda <50052685+schroda@users.noreply.github.com>
Date: Sun, 25 Jan 2026 03:22:15 +0100
Subject: [PATCH] Fix source language filter

In case the saved "selected languages" contained languages that did not have any installed source, they caused TypeErrors when trying to access them in e.g. "sourcesByLanguage".
---
 .../components/SourceLanguageSelect.tsx       | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/src/features/source/components/SourceLanguageSelect.tsx b/src/features/source/components/SourceLanguageSelect.tsx
index 25388035..48578190 100644
--- a/src/features/source/components/SourceLanguageSelect.tsx
+++ b/src/features/source/components/SourceLanguageSelect.tsx
@@ -68,37 +68,38 @@ export const SourceLanguageSelect = ({
     const languagesSortedBySelectState = useMemo(
         () =>
             toUniqueLanguageCodes([
-                ...tmpSelectedLanguages.toSorted(languageSortComparator),
+                ...tmpSelectedLanguages
+                    .filter((language) => languages.includes(language))
+                    .toSorted(languageSortComparator),
                 ...languages.toSorted(languageSortComparator),
             ]),
         [languages, tmpSelectedLanguages],
     );
 
     const flattenedSourcesByLanguages = useMemo(
-        () => Object.values(languagesSortedBySelectState.map((language) => sourcesByLanguage[language])).flat(),
+        () => languagesSortedBySelectState.map((language) => sourcesByLanguage[language] ?? []).flat(),
         [languagesSortedBySelectState, sourcesByLanguage],
     );
 
     const groupCounts = useMemo(
         () =>
             languagesSortedBySelectState.map((language) => {
-                const isEnabled = tmpSelectedLanguages.includes(language);
+                const isEnabled = tmpSelectedLanguages
+                    .filter((selectedLanguage) => languages.includes(selectedLanguage))
+                    .includes(language);
                 if (!isEnabled) {
                     return 0;
                 }
 
-                return sourcesByLanguage[language]?.length ?? 0;
+                return sourcesByLanguage[language].length;
             }),
-        [sourcesByLanguage, languagesSortedBySelectState],
+        [sourcesByLanguage, languagesSortedBySelectState, languages],
     );
 
     const computeItemKey = VirtuosoUtil.useCreateGroupedComputeItemKey(
         groupCounts,
         useCallback((index) => languagesSortedBySelectState[index], [languagesSortedBySelectState]),
-        useCallback(
-            (index) => flattenedSourcesByLanguages[index].id,
-            [sourcesByLanguage, languagesSortedBySelectState],
-        ),
+        useCallback((index) => flattenedSourcesByLanguages[index].id, [flattenedSourcesByLanguages]),
     );
 
     const handleCancel = () => {