Fixed: Mul file not recognized as such and listing pretty much all languages.

core/src/main/java/org/kiwix/kiwixmobile/core/data/Repository.kt

@@ -68,9 +68,21 @@ class Repository @Inject internal constructor(
       .observeOn(mainThread)
 
   override fun booksOnDiskAsListItems(): Flowable<List<BooksOnDiskListItem>> = bookDao.books()
-    .map { it.sortedBy { bookOnDisk -> bookOnDisk.book.language + bookOnDisk.book.title } }
-    .map {
-      HeaderizableList<BooksOnDiskListItem, BookOnDisk, LanguageItem>(it).foldOverAddingHeaders(
+    .map { books ->
+      books.flatMap { bookOnDisk ->
+        // Split languages if there are multiple, otherwise return the single book. Bug fix #3892
+        if (bookOnDisk.book.language.contains(',')) {
+          bookOnDisk.book.language.split(',').map { lang ->
+            bookOnDisk.copy(book = bookOnDisk.book.copy(language = lang.trim()))
+          }
+        } else {
+          listOf(bookOnDisk)
+        }
+      }.distinctBy { it.book.language to it.book.title }
+        .sortedBy { it.book.language + it.book.title }
+    }
+    .map { items ->
+      HeaderizableList<BooksOnDiskListItem, BookOnDisk, LanguageItem>(items).foldOverAddingHeaders(
         { bookOnDisk -> LanguageItem(bookOnDisk.locale) },
         { current, next -> current.locale.displayName != next.locale.displayName }
       )

core/src/main/java/org/kiwix/kiwixmobile/core/entity/LibraryNetworkEntity.kt

@@ -94,5 +94,41 @@ class LibraryNetworkEntity {
 
     // Only use the book's id to generate a hash code
     override fun hashCode(): Int = id.hashCode()
+
+    @Suppress("LongParameterList")
+    fun copy(
+      language: String = this.language,
+      title: String = this.title,
+      description: String? = this.description,
+      creator: String = this.creator,
+      publisher: String = this.publisher,
+      favicon: String = this.favicon,
+      faviconMimeType: String? = this.faviconMimeType,
+      date: String = this.date,
+      url: String? = this.url,
+      articleCount: String? = this.articleCount,
+      mediaCount: String? = this.mediaCount,
+      size: String = this.size,
+      bookName: String? = this.bookName,
+      tags: String? = this.tags
+    ): Book {
+      return Book().apply {
+        this.id = [email protected]
+        this.title = title
+        this.description = description
+        this.language = language
+        this.creator = creator
+        this.publisher = publisher
+        this.favicon = favicon
+        this.faviconMimeType = faviconMimeType
+        this.date = date
+        this.url = url
+        this.articleCount = articleCount
+        this.mediaCount = mediaCount
+        this.size = size
+        this.bookName = bookName
+        this.tags = tags
+      }
+    }
   }
 }