From 33a01ec1b4a6957a4451a62b6b29b94829c42942 Mon Sep 17 00:00:00 2001
From: Arthur Hung <arthurhung@google.com>
Date: Wed, 23 Mar 2022 14:28:14 +0000
Subject: [PATCH] Prevent crash when unregsiter the broadcast

Make sure the receiver could be generated and registered when `onStart`
and cleared when `onStop`.

Bug: 225214384
Test: Show error dialog, atest WindowInputTests
Change-Id: Ib39629180aac1a7aa418e9c7e540922c7f865718
---
 .../am/AppWaitingForDebuggerDialog.java       |  3 --
 .../android/server/am/BaseErrorDialog.java    | 37 +++++++++++++------
 .../android/server/wm/FactoryErrorDialog.java |  3 --
 3 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/services/core/java/com/android/server/am/AppWaitingForDebuggerDialog.java b/services/core/java/com/android/server/am/AppWaitingForDebuggerDialog.java
index 262e79521e8c6..9b5f18caf71a4 100644
--- a/services/core/java/com/android/server/am/AppWaitingForDebuggerDialog.java
+++ b/services/core/java/com/android/server/am/AppWaitingForDebuggerDialog.java
@@ -57,9 +57,6 @@ final class AppWaitingForDebuggerDialog extends BaseErrorDialog {
         attrs.setTitle("Waiting For Debugger: " + app.info.processName);
         getWindow().setAttributes(attrs);
     }
-    
-    public void onStop() {
-    }
 
     @Override
     protected void closeDialog() {
diff --git a/services/core/java/com/android/server/am/BaseErrorDialog.java b/services/core/java/com/android/server/am/BaseErrorDialog.java
index 259dd8ec567df..b1cfd7fa0f580 100644
--- a/services/core/java/com/android/server/am/BaseErrorDialog.java
+++ b/services/core/java/com/android/server/am/BaseErrorDialog.java
@@ -16,6 +16,8 @@
 
 package com.android.server.am;
 
+import static android.content.Context.RECEIVER_EXPORTED;
+
 import android.app.AlertDialog;
 import android.content.BroadcastReceiver;
 import android.content.Context;
@@ -34,6 +36,7 @@ public class BaseErrorDialog extends AlertDialog {
     private static final int DISABLE_BUTTONS = 1;
 
     private boolean mConsuming = true;
+    private BroadcastReceiver mReceiver;
 
     public BaseErrorDialog(Context context) {
         super(context, com.android.internal.R.style.Theme_DeviceDefault_Dialog_AppError);
@@ -52,14 +55,33 @@ public class BaseErrorDialog extends AlertDialog {
         super.onStart();
         mHandler.sendEmptyMessage(DISABLE_BUTTONS);
         mHandler.sendMessageDelayed(mHandler.obtainMessage(ENABLE_BUTTONS), 1000);
-        getContext().registerReceiver(mReceiver,
-                new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS), Context.RECEIVER_EXPORTED);
+        if (mReceiver == null) {
+            mReceiver = new BroadcastReceiver() {
+                @Override
+                public void onReceive(Context context, Intent intent) {
+                    if (Intent.ACTION_CLOSE_SYSTEM_DIALOGS.equals(intent.getAction())) {
+                        closeDialog();
+                    }
+                }
+            };
+            getContext().registerReceiver(mReceiver,
+                    new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS), RECEIVER_EXPORTED);
+        }
     }
 
     @Override
     protected void onStop() {
         super.onStop();
-        getContext().unregisterReceiver(mReceiver);
+        if (mReceiver != null) {
+            try {
+                getContext().unregisterReceiver(mReceiver);
+            } catch (IllegalArgumentException e) {
+                // Receiver not registered exception.
+                android.util.Slog.e("BaseErrorDialog",
+                        "unregisterReceiver threw exception: " + e.getMessage());
+            }
+            mReceiver = null;
+        }
     }
 
     public boolean dispatchKeyEvent(KeyEvent event) {
@@ -107,13 +129,4 @@ public class BaseErrorDialog extends AlertDialog {
             dismiss();
         }
     }
-
-    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
-        @Override
-        public void onReceive(Context context, Intent intent) {
-            if (Intent.ACTION_CLOSE_SYSTEM_DIALOGS.equals(intent.getAction())) {
-                closeDialog();
-            }
-        }
-    };
 }
diff --git a/services/core/java/com/android/server/wm/FactoryErrorDialog.java b/services/core/java/com/android/server/wm/FactoryErrorDialog.java
index afdf1ee4de7fd..4ebaad98cd755 100644
--- a/services/core/java/com/android/server/wm/FactoryErrorDialog.java
+++ b/services/core/java/com/android/server/wm/FactoryErrorDialog.java
@@ -37,9 +37,6 @@ final class FactoryErrorDialog extends BaseErrorDialog {
         attrs.setTitle("Factory Error");
         getWindow().setAttributes(attrs);
     }
-    
-    public void onStop() {
-    }
 
     @Override
     protected void closeDialog() {