fix sorting of synced folder: NPE if both enabled, but one has null folder name

Signed-off-by: tobiasKaminsky <tobias@kaminsky.me>

src/main/java/com/owncloud/android/ui/activity/SyncedFoldersActivity.java

@@ -297,14 +297,21 @@ public class SyncedFoldersActivity extends FileActivity implements SyncedFolderA
             } else if (f2 == null) {
                 return 1;
             } else if (f1.isEnabled() && f2.isEnabled()) {
+                if (f1.getFolderName() == null) {
+                    return -1;
+                }
+                if (f2.getFolderName() == null) {
+                    return 1;
+                }
+
                 return f1.getFolderName().toLowerCase(Locale.getDefault()).compareTo(
                     f2.getFolderName().toLowerCase(Locale.getDefault()));
+            } else if (f1.getFolderName() == null && f2.getFolderName() == null) {
+                return 0;
             } else if (f1.isEnabled()) {
                 return -1;
             } else if (f2.isEnabled()) {
                 return 1;
-            } else if (f1.getFolderName() == null && f2.getFolderName() == null) {
-                return 0;
             } else if (f1.getFolderName() == null) {
                 return -1;
             } else if (f2.getFolderName() == null) {

src/test/java/com/owncloud/android/ui/activity/SyncedFoldersActivityTest.java

@@ -0,0 +1,185 @@
+/*
+ *
+ * Nextcloud Android client application
+ *
+ * @author Tobias Kaminsky
+ * Copyright (C) 2019 Tobias Kaminsky
+ * Copyright (C) 2019 Nextcloud GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.owncloud.android.ui.activity;
+
+import com.owncloud.android.datamodel.MediaFolderType;
+import com.owncloud.android.datamodel.SyncedFolderDisplayItem;
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import third_parties.daveKoeller.AlphanumComparator;
+
+import static org.junit.Assert.assertTrue;
+
+public class SyncedFoldersActivityTest {
+
+    @Test
+    public void regular() {
+        SyncedFolderDisplayItem[] sortedArray = {
+            create("Folder1", true),
+            create("Folder2", true),
+        };
+
+        assertTrue(sortAndTest(Arrays.asList(sortedArray)));
+    }
+
+    @Test
+    public void withNull() {
+        SyncedFolderDisplayItem[] sortedArray = {
+            null,
+            null,
+            create("Folder1", true),
+            create("Folder2", true),
+        };
+
+        assertTrue(sortAndTest(Arrays.asList(sortedArray)));
+    }
+
+    @Test
+    public void withNullAndEnableStatus() {
+        SyncedFolderDisplayItem[] sortedArray = {
+            null,
+            null,
+            create("Folder1", true),
+            create("Folder2", true),
+            create("Folder3", true),
+            create("Folder4", true),
+            create("Folder5", false),
+            create("Folder6", false),
+            create("Folder7", false),
+            create("Folder8", false),
+        };
+
+        assertTrue(sortAndTest(Arrays.asList(sortedArray)));
+    }
+
+    @Test
+    public void withNullFolderName() {
+        SyncedFolderDisplayItem[] sortedArray = {
+            null,
+            null,
+            create("Folder1", true),
+            create(null, false),
+            create("Folder2", false),
+            create("Folder3", false),
+            create("Folder4", false),
+            create("Folder5", false),
+        };
+
+        assertTrue(sortAndTest(Arrays.asList(sortedArray)));
+    }
+
+    @Test
+    public void withNullFolderNameAllEnabled() {
+        SyncedFolderDisplayItem[] sortedArray = {
+            null,
+            null,
+            create(null, true),
+            create("Folder1", true),
+            create("Folder2", true),
+            create("Folder3", true),
+            create("Folder4", true),
+        };
+
+        assertTrue(sortAndTest(Arrays.asList(sortedArray)));
+    }
+
+    private List<SyncedFolderDisplayItem> shuffle(List<SyncedFolderDisplayItem> list) {
+        List<SyncedFolderDisplayItem> shuffled = new ArrayList<>(list);
+
+        Collections.shuffle(shuffled);
+
+        return shuffled;
+    }
+
+    private boolean sortAndTest(List<SyncedFolderDisplayItem> sortedList) {
+        List<SyncedFolderDisplayItem> unsortedList = shuffle(sortedList);
+
+        return test(sortedList, SyncedFoldersActivity.sortSyncedFolderItems(unsortedList));
+    }
+
+    private List<SyncedFolderDisplayItem> sort(List<SyncedFolderDisplayItem> sortedList) {
+        List<SyncedFolderDisplayItem> unsortedList = shuffle(sortedList);
+
+        Collections.sort(unsortedList, new AlphanumComparator<>());
+
+        return unsortedList;
+    }
+
+    private boolean test(List<SyncedFolderDisplayItem> target, List<SyncedFolderDisplayItem> actual) {
+
+        for (int i = 0; i < target.size(); i++) {
+            boolean compare;
+
+            compare = target.get(i) == (actual.get(i));
+
+            if (!compare) {
+
+                System.out.println("target:");
+
+                for (SyncedFolderDisplayItem item : target) {
+                    if (item == null) {
+                        System.out.println("null");
+                    } else {
+                        System.out.println(item.getFolderName() + " " + item.isEnabled());
+                    }
+                }
+
+                System.out.println();
+                System.out.println("actual:");
+                for (SyncedFolderDisplayItem item : actual) {
+                    if (item == null) {
+                        System.out.println("null");
+                    } else {
+                        System.out.println(item.getFolderName() + " " + item.isEnabled());
+                    }
+                }
+
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    private SyncedFolderDisplayItem create(String folderName, Boolean enabled) {
+        return new SyncedFolderDisplayItem(1,
+                                           "localPath",
+                                           "remotePath",
+                                           true,
+                                           true,
+                                           true,
+                                           "test@nextcloud.com",
+                                           1,
+                                           enabled,
+                                           new ArrayList<String>(),
+                                           folderName,
+                                           2,
+                                           MediaFolderType.IMAGE);
+    }
+}