Fix brotli (#818)

server/src/main/kotlin/eu/kanade/tachiyomi/network/NetworkHelper.kt

@@ -16,6 +16,7 @@ package eu.kanade.tachiyomi.network
 // import uy.kohesive.injekt.injectLazy
 import android.content.Context
 import eu.kanade.tachiyomi.network.interceptor.CloudflareInterceptor
+import eu.kanade.tachiyomi.network.interceptor.IgnoreGzipInterceptor
 import eu.kanade.tachiyomi.network.interceptor.UncaughtExceptionInterceptor
 import eu.kanade.tachiyomi.network.interceptor.UserAgentInterceptor
 import mu.KotlinLogging
@@ -61,9 +62,10 @@ class NetworkHelper(context: Context) {
                             maxSize = 5L * 1024 * 1024, // 5 MiB
                         ),
                     )
-                    .addInterceptor(BrotliInterceptor)
                     .addInterceptor(UncaughtExceptionInterceptor())
                     .addInterceptor(UserAgentInterceptor())
+                    .addNetworkInterceptor(IgnoreGzipInterceptor())
+                    .addNetworkInterceptor(BrotliInterceptor)
 
             // if (preferences.verboseLogging().get()) {
             val httpLoggingInterceptor =

server/src/main/kotlin/eu/kanade/tachiyomi/network/interceptor/IgnoreGzipInterceptor.kt

@@ -0,0 +1,21 @@
+package eu.kanade.tachiyomi.network.interceptor
+
+import okhttp3.Interceptor
+import okhttp3.Response
+
+/**
+ * To use [okhttp3.brotli.BrotliInterceptor] as a network interceptor,
+ * add [IgnoreGzipInterceptor] right before it.
+ *
+ * This nullifies the transparent gzip of [okhttp3.internal.http.BridgeInterceptor]
+ * so gzip and Brotli are explicitly handled by the [okhttp3.brotli.BrotliInterceptor].
+ */
+class IgnoreGzipInterceptor : Interceptor {
+    override fun intercept(chain: Interceptor.Chain): Response {
+        var request = chain.request()
+        if (request.header("Accept-Encoding") == "gzip") {
+            request = request.newBuilder().removeHeader("Accept-Encoding").build()
+        }
+        return chain.proceed(request)
+    }
+}