IssueTracker

Component used:

Version used: AppCompat 1.5.0-beta01 and later

Devices/Android versions reproduced on: OnePlus 7T running Android 11 (LineageOS 18.1), Pixel 5 Running Android 13.

Since all AppCompat releases later than 1.5.0-beta01, the downstream MDC MaterialButton component has experienced a double ripple effect. This is not the fault of MDC, but rather seemingly a breakage within AppCompat. I have attached an image of the issue.

Since then, I have become unable to upgrade many of the dependencies within my app (including MDC), as they will bring in new AppCompat versions and cause the ripple bug.

Looking through the source code, I am under the impression that the breakage was introduced in e8769968f3530f3dc40a547c373bcfb00ad72c13 here:

@@ -27,6 +27,7 @@
 import android.graphics.PorterDuffColorFilter;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.Drawable.ConstantState;
+import android.graphics.drawable.LayerDrawable;
 import android.os.Build;
 import android.util.AttributeSet;
 import android.util.Log;
@@ -437,6 +438,8 @@
     }
 
     static void tintDrawable(Drawable drawable, TintInfo tint, int[] state) {
+        int[] drawableState = drawable.getState();
+
         if (DrawableUtils.canSafelyMutateDrawable(drawable)
                 && drawable.mutate() != drawable) {
             Log.d(TAG, "Mutated drawable is not the same instance as the input.");
@@ -452,6 +455,13 @@
             drawable.clearColorFilter();
         }
 
+        // Workaround for b/232275112 where LayerDrawable loses its state on mutate().
+        if (drawable instanceof LayerDrawable && drawable.isStateful()) {
+            // Clear state first, otherwise setState() is a no-op.
+            drawable.setState(new int[0]);
+            drawable.setState(drawableState);
+        }
+
         if (Build.VERSION.SDK_INT <= 23) {
             // Pre-v23 there is no guarantee that a state change will invoke an invalidation,
             // so we force it ourselves

However I am unable to properly bisect the diff between 1.5.0-alpha01 and 1.5.0-beta01 since I'm unable to properly substitute a custom AppCompat into MDC. However, none of the remaining diff seemed related to Drawables (Which would feasibly cause the ripple bug), so this specific change feels like the culprit.

I understand there was a previous instance of this reported, but that issue seems to have been abandoned without anyone being assigned to resolve it.