Fix some issues when reading/saving images (#993)

* Fix unsupported mime type error when saving images

Avoid using platform mime type map to get extensions as it may not have
all mime types we support.

* Fix jxl images downloading/reading

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

@@ -17,6 +17,7 @@ import logcat.LogPriority
 import tachiyomi.core.common.i18n.stringResource
 import tachiyomi.core.common.storage.extension
 import tachiyomi.core.common.util.lang.launchIO
+import tachiyomi.core.common.util.system.ImageUtil
 import tachiyomi.core.common.util.system.logcat
 import tachiyomi.domain.category.interactor.GetCategories
 import tachiyomi.domain.chapter.model.Chapter
@@ -160,7 +161,7 @@ class DownloadManager(
     fun buildPageList(source: Source, manga: Manga, chapter: Chapter): List<Page> {
         val chapterDir = provider.findChapterDir(chapter.name, chapter.scanlator, manga.title, source)
         val files = chapterDir?.listFiles().orEmpty()
-            .filter { "image" in it.type.orEmpty() }
+            .filter { it.isFile && ImageUtil.isImage(it.name) { it.openInputStream() } }
 
         if (files.isEmpty()) {
             throw Exception(context.stringResource(MR.strings.page_list_empty_error))

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

@@ -523,14 +523,8 @@ class Downloader(
      * @param file the file where the image is already downloaded.
      */
     private fun getImageExtension(response: Response, file: UniFile): String {
-        // Read content type if available.
         val mime = response.body.contentType()?.run { if (type == "image") "image/$subtype" else null }
-            // Else guess from the uri.
-            ?: context.contentResolver.getType(file.uri)
-            // Else read magic numbers.
-            ?: ImageUtil.findImageType { file.openInputStream() }?.mime
-
-        return ImageUtil.getExtensionFromMimeType(mime)
+        return ImageUtil.getExtensionFromMimeType(mime) { file.openInputStream() }
     }
 
     private fun splitTallImageIfNeeded(page: Page, tmpDir: UniFile) {

app/src/main/java/eu/kanade/tachiyomi/data/saver/ImageSaver.kt

@@ -7,6 +7,7 @@ import android.net.Uri
 import android.os.Build
 import android.os.Environment
 import android.provider.MediaStore
+import android.webkit.MimeTypeMap
 import androidx.annotation.RequiresApi
 import androidx.core.content.contentValuesOf
 import androidx.core.net.toUri
@@ -65,21 +66,26 @@ class ImageSaver(
         filename: String,
         data: () -> InputStream,
     ): Uri {
-        val pictureDir =
+        val isMimeTypeSupported = MimeTypeMap.getSingleton().hasMimeType(type.mime)
+
+        val pictureDir = if (isMimeTypeSupported) {
             MediaStore.Images.Media.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
+        } else {
+            MediaStore.Files.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
+        }
 
         val imageLocation = (image.location as Location.Pictures).relativePath
         val relativePath = listOf(
-            Environment.DIRECTORY_PICTURES,
+            if (isMimeTypeSupported) Environment.DIRECTORY_PICTURES else Environment.DIRECTORY_DOCUMENTS,
             context.stringResource(MR.strings.app_name),
             imageLocation,
         ).joinToString(File.separator)
 
         val contentValues = contentValuesOf(
-            MediaStore.Images.Media.RELATIVE_PATH to relativePath,
-            MediaStore.Images.Media.DISPLAY_NAME to image.name,
-            MediaStore.Images.Media.MIME_TYPE to type.mime,
-            MediaStore.Images.Media.DATE_MODIFIED to Instant.now().epochSecond,
+            MediaStore.MediaColumns.RELATIVE_PATH to relativePath,
+            MediaStore.MediaColumns.DISPLAY_NAME to if (isMimeTypeSupported) image.name else filename,
+            MediaStore.MediaColumns.MIME_TYPE to type.mime,
+            MediaStore.MediaColumns.DATE_MODIFIED to Instant.now().epochSecond,
         )
 
         val picture = findUriOrDefault(relativePath, filename) {

core/common/src/main/kotlin/tachiyomi/core/common/util/system/ImageUtil.kt

@@ -13,7 +13,6 @@ import android.graphics.drawable.ColorDrawable
 import android.graphics.drawable.Drawable
 import android.graphics.drawable.GradientDrawable
 import android.os.Build
-import android.webkit.MimeTypeMap
 import androidx.annotation.ColorInt
 import androidx.core.graphics.alpha
 import androidx.core.graphics.applyCanvas
@@ -29,7 +28,6 @@ import okio.BufferedSource
 import tachiyomi.decoder.Format
 import tachiyomi.decoder.ImageDecoder
 import java.io.InputStream
-import java.net.URLConnection
 import java.util.Locale
 import kotlin.math.abs
 import kotlin.math.max
@@ -40,12 +38,8 @@ object ImageUtil {
     fun isImage(name: String?, openStream: (() -> InputStream)? = null): Boolean {
         if (name == null) return false
 
-        val contentType = try {
-            URLConnection.guessContentTypeFromName(name)
-        } catch (e: Exception) {
-            null
-        } ?: openStream?.let { findImageType(it)?.mime }
-        return contentType?.startsWith("image/") ?: false
+        val extension = name.substringAfterLast('.')
+        return ImageType.entries.any { it.extension == extension } || openStream?.let { findImageType(it) } != null
     }
 
     fun findImageType(openStream: () -> InputStream): ImageType? {
@@ -69,10 +63,9 @@ object ImageUtil {
         }
     }
 
-    fun getExtensionFromMimeType(mime: String?): String {
-        return MimeTypeMap.getSingleton().getExtensionFromMimeType(mime)
-            ?: SUPPLEMENTARY_MIMETYPE_MAPPING[mime]
-            ?: "jpg"
+    fun getExtensionFromMimeType(mime: String?, openStream: () -> InputStream): String {
+        val type = mime?.let { ImageType.entries.find { it.mime == mime } } ?: findImageType(openStream)
+        return type?.extension ?: "jpg"
     }
 
     fun isAnimatedAndSupported(source: BufferedSource): Boolean {
@@ -558,12 +551,6 @@ object ImageUtil {
     }
 
     private val optimalImageHeight = getDisplayMaxHeightInPx * 2
-
-    // Android doesn't include some mappings
-    private val SUPPLEMENTARY_MIMETYPE_MAPPING = mapOf(
-        // https://issuetracker.google.com/issues/182703810
-        "image/jxl" to "jxl",
-    )
 }
 
 val getDisplayMaxHeightInPx: Int