Fix loading local manga in some corner cases

app/src/main/kotlin/org/koitharu/kotatsu/details/ui/pager/pages/PagesViewModel.kt

@@ -105,7 +105,14 @@ class PagesViewModel @Inject constructor(
 			chaptersLoader.peekChapter(it) != null
 		} ?: state.details.allChapters.firstOrNull()?.id ?: return
 		if (!chaptersLoader.hasPages(initialChapterId)) {
-			chaptersLoader.loadSingleChapter(initialChapterId)
+			var hasPages = chaptersLoader.loadSingleChapter(initialChapterId)
+			while (!hasPages) {
+				if (chaptersLoader.loadPrevNextChapter(state.details, initialChapterId, isNext = true)) {
+					hasPages = chaptersLoader.snapshot().isNotEmpty()
+				} else {
+					break
+				}
+			}
 		}
 		updateList(state.readerState)
 	}

app/src/main/kotlin/org/koitharu/kotatsu/local/data/input/LocalMangaParser.kt

@@ -61,7 +61,9 @@ class LocalMangaParser(private val uri: Uri) {
 			val index = MangaIndex.read(fileSystem, rootPath / ENTRY_NAME_INDEX)
 			val mangaInfo = index?.getMangaInfo()
 			if (mangaInfo != null) {
-				val coverEntry: Path? = index.getCoverEntry()?.let { rootPath / it }
+				val coverEntry: Path? = index.getCoverEntry()?.let { rootPath / it }?.takeIf {
+					fileSystem.exists(it)
+				}
 				mangaInfo.copy(
 					source = LocalMangaSource,
 					url = rootFile.toUri().toString(),

app/src/main/kotlin/org/koitharu/kotatsu/reader/domain/ChaptersLoader.kt

@@ -1,6 +1,7 @@
 package org.koitharu.kotatsu.reader.domain
 
 import android.util.LongSparseArray
+import androidx.annotation.CheckResult
 import dagger.hilt.android.scopes.ViewModelScoped
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
@@ -32,12 +33,12 @@ class ChaptersLoader @Inject constructor(
 		}
 	}
 
-	suspend fun loadPrevNextChapter(manga: MangaDetails, currentId: Long, isNext: Boolean) {
+	suspend fun loadPrevNextChapter(manga: MangaDetails, currentId: Long, isNext: Boolean): Boolean {
 		val chapters = manga.allChapters
 		val predicate: (MangaChapter) -> Boolean = { it.id == currentId }
 		val index = if (isNext) chapters.indexOfFirst(predicate) else chapters.indexOfLast(predicate)
-		if (index == -1) return
+		if (index == -1) return false
-		val newChapter = chapters.getOrNull(if (isNext) index + 1 else index - 1) ?: return
+		val newChapter = chapters.getOrNull(if (isNext) index + 1 else index - 1) ?: return false
 		val newPages = loadChapter(newChapter.id)
 		mutex.withLock {
 			if (chapterPages.chaptersSize > 1) {
@@ -56,13 +57,16 @@ class ChaptersLoader @Inject constructor(
 				chapterPages.addFirst(newChapter.id, newPages)
 			}
 		}
+		return true
 	}
 
-	suspend fun loadSingleChapter(chapterId: Long) {
+	@CheckResult
+	suspend fun loadSingleChapter(chapterId: Long): Boolean {
 		val pages = loadChapter(chapterId)
-		mutex.withLock {
+		return mutex.withLock {
 			chapterPages.clear()
 			chapterPages.addLast(chapterId, pages)
+			pages.isNotEmpty()
 		}
 	}