ExtensionLoader: Set read-only to private extension files (#10007)

app/src/main/java/eu/kanade/tachiyomi/extension/util/ExtensionLoader.kt

@@ -14,6 +14,7 @@ import eu.kanade.tachiyomi.source.CatalogueSource
 import eu.kanade.tachiyomi.source.Source
 import eu.kanade.tachiyomi.source.SourceFactory
 import eu.kanade.tachiyomi.util.lang.Hash
+import eu.kanade.tachiyomi.util.storage.copyAndSetReadOnlyTo
 import kotlinx.coroutines.async
 import kotlinx.coroutines.awaitAll
 import kotlinx.coroutines.runBlocking
@@ -97,7 +98,8 @@ internal object ExtensionLoader {
 
         val target = File(getPrivateExtensionDir(context), "${extension.packageName}.$PRIVATE_EXTENSION_EXTENSION")
         return try {
-            file.copyTo(target, overwrite = true)
+            file.delete()
+            file.copyAndSetReadOnlyTo(target, overwrite = true)
             if (currentExtension != null) {
                 ExtensionInstallReceiver.notifyReplaced(context, extension.packageName)
             } else {

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

@@ -23,3 +23,41 @@ fun File.getUriCompat(context: Context): Uri {
         this.toUri()
     }
 }
+
+/**
+ * Copies this file to the given [target] file while marking the file as read-only.
+ *
+ * @see File.copyTo
+ */
+fun File.copyAndSetReadOnlyTo(target: File, overwrite: Boolean = false, bufferSize: Int = DEFAULT_BUFFER_SIZE): File {
+    if (!this.exists()) {
+        throw NoSuchFileException(file = this, reason = "The source file doesn't exist.")
+    }
+
+    if (target.exists()) {
+        if (!overwrite) {
+            throw FileAlreadyExistsException(file = this, other = target, reason = "The destination file already exists.")
+        } else if (!target.delete()) {
+            throw FileAlreadyExistsException(file = this, other = target, reason = "Tried to overwrite the destination, but failed to delete it.")
+        }
+    }
+
+    if (this.isDirectory) {
+        if (!target.mkdirs()) {
+            throw FileSystemException(file = this, other = target, reason = "Failed to create target directory.")
+        }
+    } else {
+        target.parentFile?.mkdirs()
+
+        this.inputStream().use { input ->
+            target.outputStream().use { output ->
+                // Set read-only
+                target.setReadOnly()
+
+                input.copyTo(output, bufferSize)
+            }
+        }
+    }
+
+    return target
+}