From 058d2d10e2d503f141c8fbe2ce8f2adaaeeba2cc Mon Sep 17 00:00:00 2001
From: Doris Ling <dling@google.com>
Date: Thu, 3 Aug 2017 10:54:48 -0700
Subject: [PATCH] Fix crash when dismissing suggestions.

When the suggestions are in default mode and the number of suggestions
are more than the default count, we set the sublist of the suggestions
list as the suggestion adapter data. In this case, operation on the
suggestions list should be done in the sublist instead of the original
list to maintain the list consistency check.

Hence, when dismissing the suggestion, change to remove the suggestion
from the sugestion adapter instead of from the dashboard adapter, so
that any following interaction with the suggestions will not trigger the
concurrent modification exception.

Change-Id: I4caba74cfcc7bd0d53ad8c7dffcb127b3ebd845d
Merged-In: I970b6af8a1c72bc0c3ee89fef890ae6a669c71d2
Fix: 64279080
Test: make RunSettingsRoboTests
---
 .../settings/dashboard/DashboardAdapter.java  |  3 +--
 .../suggestions/SuggestionAdapter.java        |  4 +++
 .../dashboard/DashboardAdapterTest.java       | 26 +++++++++++++++++--
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/src/com/android/settings/dashboard/DashboardAdapter.java b/src/com/android/settings/dashboard/DashboardAdapter.java
index 8f4b27d2ef5..70fd659c8d0 100644
--- a/src/com/android/settings/dashboard/DashboardAdapter.java
+++ b/src/com/android/settings/dashboard/DashboardAdapter.java
@@ -232,8 +232,7 @@ public class DashboardAdapter extends RecyclerView.Adapter<DashboardAdapter.Dash
                     .build();
             notifyDashboardDataChanged(prevData);
         } else {
-            suggestions.remove(suggestion);
-            mSuggestionAdapter.notifyDataSetChanged();
+            mSuggestionAdapter.removeSuggestion(suggestion);
         }
     }
 
diff --git a/src/com/android/settings/dashboard/suggestions/SuggestionAdapter.java b/src/com/android/settings/dashboard/suggestions/SuggestionAdapter.java
index 7a2ab2da2d9..45396807f87 100644
--- a/src/com/android/settings/dashboard/suggestions/SuggestionAdapter.java
+++ b/src/com/android/settings/dashboard/suggestions/SuggestionAdapter.java
@@ -134,4 +134,8 @@ public class SuggestionAdapter extends RecyclerView.Adapter<DashboardItemHolder>
         return null;
     }
 
+    public void removeSuggestion(Tile suggestion) {
+        mSuggestions.remove(suggestion);
+        notifyDataSetChanged();
+    }
 }
diff --git a/tests/robotests/src/com/android/settings/dashboard/DashboardAdapterTest.java b/tests/robotests/src/com/android/settings/dashboard/DashboardAdapterTest.java
index df16b4b56d9..4d81320a9f7 100644
--- a/tests/robotests/src/com/android/settings/dashboard/DashboardAdapterTest.java
+++ b/tests/robotests/src/com/android/settings/dashboard/DashboardAdapterTest.java
@@ -34,14 +34,12 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.res.Resources;
 import android.content.res.TypedArray;
-import android.graphics.drawable.ColorDrawable;
 import android.graphics.drawable.Icon;
 import android.os.Bundle;
 import android.support.v7.widget.RecyclerView;
 import android.util.DisplayMetrics;
 import android.view.LayoutInflater;
 import android.view.View;
-import android.widget.LinearLayout;
 import android.widget.RelativeLayout;
 
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
@@ -355,6 +353,30 @@ public class DashboardAdapterTest {
         verify(adapter, never()).notifyDashboardDataChanged(any());
     }
 
+    @Test
+    public void testSuggestionDismissed_moreThanTwoSuggestions_defaultMode_shouldNotCrash() {
+        final RecyclerView data = new RecyclerView(RuntimeEnvironment.application);
+        final View itemView = mock(View.class);
+        when(itemView.findViewById(R.id.data)).thenReturn(data);
+        final DashboardAdapter.SuggestionAndConditionContainerHolder holder =
+                new DashboardAdapter.SuggestionAndConditionContainerHolder(itemView);
+        final List<Tile> suggestions =
+                makeSuggestions("pkg1", "pkg2", "pkg3", "pkg4");
+        final DashboardAdapter adapter = spy(new DashboardAdapter(mContext, null /*savedInstance */,
+                null /* conditions */, null /* suggestionParser */, null /* callback */));
+        adapter.setCategoriesAndSuggestions(new ArrayList<>(), suggestions);
+        adapter.onBindConditionAndSuggestion(
+                holder, DashboardAdapter.SUGGESTION_CONDITION_HEADER_POSITION);
+        // default mode, only displaying 2 suggestions
+
+        adapter.onSuggestionDismissed(suggestions.get(1));
+
+        // verify operations that access the lists will not cause ConcurrentModificationException
+        assertThat(holder.data.getAdapter().getItemCount()).isEqualTo(1);
+        adapter.setCategoriesAndSuggestions(new ArrayList<>(), suggestions);
+        // should not crash
+    }
+
     @Test
     public void testSuggestioDismissed_onlySuggestion_updateDashboardData() {
         DashboardAdapter adapter =