From c0b9ad77be1e79c8958fc21bbb31e291b68593f5 Mon Sep 17 00:00:00 2001
From: Colin Lee <mncolinlee@gmail.com>
Date: Tue, 17 Dec 2019 10:41:54 -0600
Subject: [PATCH] For #4064: Update R8/ProGuard config for new Kotlin
 coroutines library (#7218)

---
 app/proguard-rules.pro | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index 5131ad636..77510c5ba 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -33,14 +33,17 @@
 
 ####################################################################################################
 # Force removal of slow Dispatchers.Main ServiceLoader
-#
-# Please remove these rules when Android Gradle Plugin 3.6+ & coroutines 1.3.0+ are both in use
 ####################################################################################################
-# Ensure the custom, fast service loader implementation is removed.
--assumevalues class kotlinx.coroutines.internal.MainDispatcherLoader {
-  boolean FAST_SERVICE_LOADER_ENABLED return false;
+# Allow R8 to optimize away the FastServiceLoader.
+# Together with ServiceLoader optimization in R8
+# this results in direct instantiation when loading Dispatchers.Main
+-assumenosideeffects class kotlinx.coroutines.internal.MainDispatcherLoader {
+    boolean FAST_SERVICE_LOADER_ENABLED return false;
+}
+
+-assumenosideeffects class kotlinx.coroutines.internal.FastServiceLoader {
+    boolean ANDROID_DETECTED return true;
 }
--checkdiscard class kotlinx.coroutines.internal.FastServiceLoader
 
 ####################################################################################################
 # Mozilla Application Services