Fix null pointer in StarredContactsPrefController

Change-Id: I9b2209825b30a6cc8dfe355632201b8082572dbb
Fixes: 80084826
Test: ZenModeStarredContactsPreferenceControllerTest.java

src/com/android/settings/notification/ZenModeStarredContactsPreferenceController.java

@@ -117,6 +117,7 @@ public class ZenModeStarredContactsPreferenceController extends
             }
         }
 
+        // values in displayContacts must not be null
         mPreference.setSummary(ListFormatter.getInstance().format(displayContacts));
     }
 
@@ -130,22 +131,32 @@ public class ZenModeStarredContactsPreferenceController extends
         return true;
     }
 
-    private List<String> getStarredContacts() {
+    @VisibleForTesting
+    List<String> getStarredContacts(Cursor cursor) {
         List<String> starredContacts = new ArrayList<>();
 
-        Cursor cursor = mContext.getContentResolver().query(ContactsContract.Contacts.CONTENT_URI,
-                new String[]{ContactsContract.Contacts.DISPLAY_NAME_PRIMARY},
-                ContactsContract.Data.STARRED + "=1", null,
-                ContactsContract.Data.TIMES_CONTACTED);
-
         if (cursor.moveToFirst()) {
             do {
-                starredContacts.add(cursor.getString(0));
+                String contact = cursor.getString(0);
+                if (contact != null) {
+                    starredContacts.add(contact);
+                }
             } while (cursor.moveToNext());
         }
         return starredContacts;
     }
 
+    private List<String> getStarredContacts() {
+        return getStarredContacts(queryData());
+    }
+
+    private Cursor queryData() {
+        return mContext.getContentResolver().query(ContactsContract.Contacts.CONTENT_URI,
+                new String[]{ContactsContract.Contacts.DISPLAY_NAME_PRIMARY},
+                ContactsContract.Data.STARRED + "=1", null,
+                ContactsContract.Data.TIMES_CONTACTED);
+    }
+
     private boolean isIntentValid() {
         return mStarredContactsIntent.resolveActivity(mPackageManager) != null
                 || mFallbackIntent.resolveActivity(mPackageManager) != null;

tests/robotests/src/com/android/settings/notification/ZenModeStarredContactsPreferenceControllerTest.java

@@ -23,12 +23,25 @@ import static com.google.common.truth.Truth.assertThat;
 
 import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static org.mockito.Mockito.doAnswer;
+import org.mockito.stubbing.Answer;
+import org.mockito.invocation.InvocationOnMock;
 
 import android.app.NotificationManager;
 import android.content.ComponentName;
+import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
+import android.database.CharArrayBuffer;
+import android.database.ContentObserver;
+import android.database.Cursor;
+import android.database.DataSetObserver;
+import android.net.Uri;
+import android.os.Bundle;
+
 import androidx.preference.Preference;
 import androidx.preference.PreferenceScreen;
 
@@ -42,6 +55,8 @@ import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 import org.robolectric.shadows.ShadowApplication;
 import org.robolectric.util.ReflectionHelpers;
+import java.util.ArrayList;
+import java.util.List;
 
 @RunWith(SettingsRobolectricTestRunner.class)
 public class ZenModeStarredContactsPreferenceControllerTest {
@@ -148,4 +163,31 @@ public class ZenModeStarredContactsPreferenceControllerTest {
 
         assertThat(mMessagesController.isAvailable()).isTrue();
     }
+
+    @Test
+    public void updateSummary_nullCursorValues() {
+        Cursor testCursorWithNullValues = mock(Cursor.class);
+        when(testCursorWithNullValues.moveToFirst()).thenReturn(true);
+
+        doAnswer(new Answer<Boolean>() {
+            int count = 0;
+            @Override
+            public Boolean answer(InvocationOnMock invocation) throws Throwable {
+                if (count < 3) {
+                    count++;
+                    return true;
+                }
+                return false;
+            }
+
+        }).when(testCursorWithNullValues).moveToNext();
+
+        when(testCursorWithNullValues.getString(0)).thenReturn(null);
+
+        // expected - no null  values
+        List<String> contacts = mMessagesController.getStarredContacts(testCursorWithNullValues);
+        for (int i = 0 ; i < contacts.size(); i++) {
+            assertThat(contacts.get(i)).isNotNull();
+        }
+    }
 }