Swallow errors when trying to determine available disk space when downloading (closes #3603)

app/src/main/java/eu/kanade/tachiyomi/data/download/Downloader.kt

@@ -267,15 +267,16 @@ class Downloader(
      * @param download the chapter to be downloaded.
      */
     private fun downloadChapter(download: Download): Observable<Download> = Observable.defer {
-        val chapterDirname = provider.getChapterDirName(download.chapter)
         val mangaDir = provider.getMangaDir(download.manga, download.source)
 
-        if (DiskUtil.getAvailableStorageSpace(mangaDir) < MIN_DISK_SPACE) {
+        val availSpace = DiskUtil.getAvailableStorageSpace(mangaDir)
+        if (availSpace != -1L && availSpace < MIN_DISK_SPACE) {
             download.status = Download.ERROR
             notifier.onError(context.getString(R.string.download_insufficient_space), download.chapter.name)
             return@defer Observable.just(download)
         }
 
+        val chapterDirname = provider.getChapterDirName(download.chapter)
         val tmpDir = mangaDir.createDirectory(chapterDirname + TMP_DIR_SUFFIX)
 
         val pageListObservable = if (download.pages == null) {

app/src/main/java/eu/kanade/tachiyomi/util/storage/DiskUtil.kt

@@ -34,14 +34,12 @@ object DiskUtil {
      * Gets the available space for the disk that a file path points to, in bytes.
      */
     fun getAvailableStorageSpace(f: UniFile): Long {
-        val stat = try {
-            StatFs(f.filePath)
+        return try {
+            val stat = StatFs(f.uri.path)
+            stat.availableBlocksLong * stat.blockSizeLong
         } catch (_: Exception) {
-            // Assume that exception is thrown when path is on external storage
-            StatFs(Environment.getExternalStorageDirectory().path)
+            -1L
         }
-
-        return stat.availableBlocksLong * stat.blockSizeLong
     }
 
     /**