From 6b37d6341f020fc6c3b2834495ac01ec548dbb05 Mon Sep 17 00:00:00 2001
From: Daniel Nishi <dhnishi@google.com>
Date: Tue, 18 Apr 2017 14:57:54 -0700
Subject: [PATCH] Gracefully handle null volumes after forgetting.

If a user tells a device to forget a storage volume and then
goes back to the PrivateVolumeForget activity from their Recents, it
attempts to re-initialize itself with a volume that it forgot.

And this makes Settings crash.

By gracefully killing the activity when we try to open
PrivateVolumeForget for a forgotten volume, we avoid this crash.

Change-Id: Ib4e881c10f0c872ce6b268b16a573960230ef99b
Fixes: 34856304
Test: Settings unit test
---
 .../deviceinfo/PrivateVolumeForget.java       | 10 ++++
 .../deviceinfo/PrivateVolumeForgetTest.java   | 52 +++++++++++++++++++
 2 files changed, 62 insertions(+)
 create mode 100644 tests/unit/src/com/android/settings/deviceinfo/PrivateVolumeForgetTest.java

diff --git a/src/com/android/settings/deviceinfo/PrivateVolumeForget.java b/src/com/android/settings/deviceinfo/PrivateVolumeForget.java
index a8e119daa10..b6d50cef75a 100644
--- a/src/com/android/settings/deviceinfo/PrivateVolumeForget.java
+++ b/src/com/android/settings/deviceinfo/PrivateVolumeForget.java
@@ -53,8 +53,18 @@ public class PrivateVolumeForget extends SettingsPreferenceFragment {
             Bundle savedInstanceState) {
         final StorageManager storage = getActivity().getSystemService(StorageManager.class);
         final String fsUuid = getArguments().getString(VolumeRecord.EXTRA_FS_UUID);
+        // Passing null will crash the StorageManager, so let's early exit.
+        if (fsUuid == null) {
+            getActivity().finish();
+            return null;
+        }
         mRecord = storage.findRecordByUuid(fsUuid);
 
+        if (mRecord == null) {
+            getActivity().finish();
+            return null;
+        }
+
         final View view = inflater.inflate(R.layout.storage_internal_forget, container, false);
         final TextView body = (TextView) view.findViewById(R.id.body);
         final Button confirm = (Button) view.findViewById(R.id.confirm);
diff --git a/tests/unit/src/com/android/settings/deviceinfo/PrivateVolumeForgetTest.java b/tests/unit/src/com/android/settings/deviceinfo/PrivateVolumeForgetTest.java
new file mode 100644
index 00000000000..be36e43dbb2
--- /dev/null
+++ b/tests/unit/src/com/android/settings/deviceinfo/PrivateVolumeForgetTest.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package com.android.settings.deviceinfo;
+
+import android.content.Intent;
+import android.content.Context;
+
+import android.os.storage.VolumeRecord;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.filters.SmallTest;
+import android.support.test.rule.ActivityTestRule;
+import android.support.test.runner.AndroidJUnit4;
+
+import com.android.settings.Settings;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class PrivateVolumeForgetTest {
+    @Rule
+    public ActivityTestRule<Settings.PrivateVolumeForgetActivity> mActivityRule =
+            new ActivityTestRule<>(Settings.PrivateVolumeForgetActivity.class, true, true);
+
+    @Test
+    public void test_invalidSetupDoesNotCrashSettings() {
+        Context targetContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
+        Intent intent = new Intent(targetContext, Settings.PrivateVolumeForgetActivity.class);
+        intent.putExtra(VolumeRecord.EXTRA_FS_UUID, "totally-fake-uuid-doesnt-even-fit-format");
+        mActivityRule.launchActivity(intent);
+
+        // Should exit gracefully without crashing.
+    }
+}
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