NEW - bug 288448: Importing exported task file in Galileo does not re-import all tasks

https://bugs.eclipse.org/bugs/show_bug.cgi?id=288448

6 files changed, 163 insertions, 174 deletions

diff --git a/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/TaskDataExportTest.java b/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/TaskDataExportTest.java
index 6aa414a6a..fe898ab38 100644
--- a/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/TaskDataExportTest.java
+++ b/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/TaskDataExportTest.java
@@ -13,13 +13,18 @@ package org.eclipse.mylyn.tasks.tests;
 
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 
+import junit.framework.TestCase;
+
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.mylyn.commons.tests.support.CommonTestUtil;
-import org.eclipse.mylyn.context.tests.AbstractContextTest;
 import org.eclipse.mylyn.internal.tasks.ui.TasksUiPlugin;
 import org.eclipse.mylyn.internal.tasks.ui.util.TaskDataExportOperation;
 import org.eclipse.mylyn.internal.tasks.ui.util.TaskDataSnapshotOperation;
@@ -31,22 +36,57 @@ import org.eclipse.swt.widgets.Shell;
  * Test case for the Task Export Wizard
  * 
  * @author Wesley Coelho
- * @author Mik Kersten (fixes)
+ * @author Mik Kersten
+ * @author Steffen Pingel
  */
-public class TaskDataExportTest extends AbstractContextTest {
+public class TaskDataExportTest extends TestCase {
+
+	private File destinationDir;
+
+	private File mylynFolder;
+
+	private final List<File> tempFiles = new ArrayList<File>();
 
 	private TaskDataExportWizard wizard;
 
 	private TaskDataExportWizardPage wizardPage;
 
-	private File destinationDir;
+	private File createDirectory(File parent, String folderName) {
+		File file = new File(parent, folderName);
+		if (!file.exists()) {
+			assertTrue(file.mkdir());
+			tempFiles.add(file);
+		}
+		return file;
+	}
 
-	private File mylynFolder;
+	private File createFile(File directory, String fileName) throws IOException {
+		File file = new File(directory, fileName);
+		if (!file.exists()) {
+			assertTrue(file.createNewFile());
+			tempFiles.add(file);
+		}
+		return file;
+	}
+
+	private List<String> getEntries(File file) throws IOException {
+		ArrayList<String> entries = new ArrayList<String>();
+		ZipInputStream zipInputStream = new ZipInputStream(new FileInputStream(file));
+		try {
+			ZipEntry entry = zipInputStream.getNextEntry();
+			while (entry != null) {
+				entries.add(entry.getName());
+				entry = zipInputStream.getNextEntry();
+			}
+		} finally {
+			zipInputStream.close();
+		}
+		Collections.sort(entries);
+		return entries;
+	}
 
 	@Override
 	protected void setUp() throws Exception {
-		super.setUp();
-
 		// Create the export wizard
 		wizard = new TaskDataExportWizard();
 		wizard.addPages();
@@ -58,59 +98,33 @@ public class TaskDataExportTest extends AbstractContextTest {
 		mylynFolder = new File(TasksUiPlugin.getDefault().getDataDirectory());
 		destinationDir = new File(mylynFolder.getParent(), "TestDir");
 		CommonTestUtil.deleteFolder(destinationDir);
-		destinationDir.mkdir();
+		createDirectory(destinationDir.getParentFile(), destinationDir.getName());
 
 		// Create folder/file structure
-		File tasklist = new File(mylynFolder, "tasks.xml.zip");
-		if (!tasklist.exists()) {
-			assertTrue(tasklist.createNewFile());
-		}
-		File hidden = new File(mylynFolder, ".hidden");
-		if (!hidden.exists()) {
-			assertTrue(hidden.createNewFile());
-		}
-		File tasksandstuff = new File(mylynFolder, "tasksandstuff");
-		if (!tasksandstuff.exists()) {
-			assertTrue(tasksandstuff.mkdir());
-		}
-		File backup = new File(mylynFolder, "backup");
-		if (!backup.exists()) {
-			assertTrue(backup.mkdir());
-		}
-		File tasksFile = new File(tasksandstuff, "file1.xml.zip");
-		if (!tasksFile.exists()) {
-			assertTrue(tasksFile.createNewFile());
-		}
-
-		File tasksSubDir = new File(tasksandstuff, "sub");
-		if (!tasksSubDir.exists()) {
-			assertTrue(tasksSubDir.mkdir());
-		}
-
-		File tasksSubDirFile = new File(tasksSubDir, "file2.xml.zip");
-		if (!tasksSubDirFile.exists()) {
-			assertTrue(tasksSubDirFile.createNewFile());
-		}
-
+		createFile(mylynFolder, "tasks.xml.zip");
+		createFile(mylynFolder, "tasklist.xml.zip");
+		createFile(mylynFolder, "my-tasklist.xml.zip");
+		createFile(mylynFolder, ".hidden");
+
+		createDirectory(mylynFolder, "my-attachments");
+		createDirectory(mylynFolder, "attachments");
+		createDirectory(mylynFolder, "backup");
+
+		File tasksandstuff = createDirectory(mylynFolder, "tasksandstuff");
+		createFile(tasksandstuff, "file1.xml.zip");
+		File taskSubDir = createDirectory(tasksandstuff, "sub");
+		createFile(taskSubDir, "file2.xml.zip");
 	}
 
 	@Override
 	protected void tearDown() throws Exception {
 		wizard.dispose();
 		wizardPage.dispose();
-		CommonTestUtil.deleteFolder(destinationDir);
-		// Create folder/file structure
-		File tasklist = new File(mylynFolder, "tasks.xml.zip");
-		tasklist.delete();
-		File hidden = new File(mylynFolder, ".hidden");
-		hidden.delete();
-		File tasks = new File(mylynFolder, "tasksandstuff");
-		File tasksSubDir = new File(tasks, "sub");
-		File backup = new File(mylynFolder, "backup");
-		CommonTestUtil.deleteFolder(backup);
-		CommonTestUtil.deleteFolder(tasksSubDir);
-		CommonTestUtil.deleteFolder(tasks);
-		super.tearDown();
+
+		Collections.reverse(tempFiles);
+		for (File file : tempFiles) {
+			file.delete();
+		}
 	}
 
 	/**
@@ -124,81 +138,43 @@ public class TaskDataExportTest extends AbstractContextTest {
 		// check that the task list file was exported
 		File[] files = destinationDir.listFiles();
 		assertEquals(1, files.length);
-		ZipInputStream zipInputStream = new ZipInputStream(new FileInputStream(files[0]));
-		try {
-			ArrayList<String> entries = new ArrayList<String>();
-			ZipEntry entry = zipInputStream.getNextEntry();
-			while (entry != null) {
-				entries.add(entry.getName());
-				entry = zipInputStream.getNextEntry();
-			}
-			assertFalse(entries.contains(".hidden"));
-			assertTrue(entries.contains("tasks.xml.zip"));
-			assertTrue(entries.contains("tasksandstuff/file1.xml.zip"));
-			assertTrue(entries.contains("tasksandstuff/sub/file2.xml.zip"));
-			assertFalse(entries.contains("backup"));
-		} finally {
-			zipInputStream.close();
-		}
+
+		List<String> entries = getEntries(files[0]);
+		assertEquals(Arrays.asList("my-tasklist.xml.zip", "repositories.xml.zip", "tasks.xml.zip",
+				"tasksandstuff/file1.xml.zip", "tasksandstuff/sub/file2.xml.zip"), entries);
 	}
 
-	public void testSnapshotWithoutContext() throws Exception {
-		final TaskDataExportOperation backupJob = new TaskDataSnapshotOperation(destinationDir.getPath(),
-				"testBackup.zip");
+	public void testSnapshotWithContext() throws Exception {
 		File activityFile = new File(mylynFolder, "contexts/activity.xml.zip");
-		if (activityFile.exists()) {
-			assertTrue(activityFile.delete());
+		if (!activityFile.exists()) {
+			assertTrue(activityFile.createNewFile());
 		}
+
+		final TaskDataExportOperation backupJob = new TaskDataSnapshotOperation(destinationDir.getPath(),
+				"testBackup.zip");
 		backupJob.run(new NullProgressMonitor());
+
 		// check that the task list file was exported
 		File[] files = destinationDir.listFiles();
 		assertEquals(1, files.length);
-		ZipInputStream zipInputStream = new ZipInputStream(new FileInputStream(files[0]));
-		try {
-			ArrayList<String> entries = new ArrayList<String>();
-			ZipEntry entry = zipInputStream.getNextEntry();
-			while (entry != null) {
-				entries.add(entry.getName());
-				entry = zipInputStream.getNextEntry();
-			}
-			assertFalse(entries.contains(".hidden"));
-			assertTrue(entries.contains("tasks.xml.zip"));
-			assertTrue(entries.contains("repositories.xml.zip"));
-			assertFalse(entries.contains("contexts/activity.xml.zip"));
-			assertFalse(entries.contains("tasks"));
-			assertEquals(2, entries.size());
-		} finally {
-			zipInputStream.close();
-		}
+		List<String> entries = getEntries(files[0]);
+		assertEquals(Arrays.asList("contexts/activity.xml.zip", "repositories.xml.zip", "tasks.xml.zip"), entries);
 	}
 
-	public void testSnapshotWithContext() throws Exception {
-		final TaskDataExportOperation backupJob = new TaskDataSnapshotOperation(destinationDir.getPath(),
-				"testBackup.zip");
+	public void testSnapshotWithoutContext() throws Exception {
 		File activityFile = new File(mylynFolder, "contexts/activity.xml.zip");
-		if (!activityFile.exists()) {
-			assertTrue(activityFile.createNewFile());
+		if (activityFile.exists()) {
+			assertTrue(activityFile.delete());
 		}
+
+		final TaskDataExportOperation backupJob = new TaskDataSnapshotOperation(destinationDir.getPath(),
+				"testBackup.zip");
 		backupJob.run(new NullProgressMonitor());
+
 		// check that the task list file was exported
 		File[] files = destinationDir.listFiles();
 		assertEquals(1, files.length);
-		ZipInputStream zipInputStream = new ZipInputStream(new FileInputStream(files[0]));
-		try {
-			ArrayList<String> entries = new ArrayList<String>();
-			ZipEntry entry = zipInputStream.getNextEntry();
-			while (entry != null) {
-				entries.add(entry.getName());
-				entry = zipInputStream.getNextEntry();
-			}
-			assertFalse(entries.contains(".hidden"));
-			assertTrue(entries.contains("tasks.xml.zip"));
-			assertTrue(entries.contains("repositories.xml.zip"));
-			assertTrue(entries.contains("contexts/activity.xml.zip"));
-			assertFalse(entries.contains("tasks"));
-			assertEquals(3, entries.size());
-		} finally {
-			zipInputStream.close();
-		}
+		List<String> entries = getEntries(files[0]);
+		assertEquals(Arrays.asList("repositories.xml.zip", "tasks.xml.zip"), entries);
 	}
 }
diff --git a/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/TaskDataImportTest.java b/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/TaskDataImportTest.java
index 6b746b2d0..6e8233efd 100644
--- a/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/TaskDataImportTest.java
+++ b/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/TaskDataImportTest.java
@@ -11,7 +11,6 @@
 
 package org.eclipse.mylyn.tasks.tests;
 
-import java.io.File;
 import java.util.Collection;
 
 import org.eclipse.mylyn.context.tests.AbstractContextTest;
@@ -26,9 +25,10 @@ import org.eclipse.mylyn.internal.tasks.ui.wizards.TaskDataImportWizardPage;
 import org.eclipse.swt.widgets.Shell;
 
 /**
- * Test case for the Task Import Wizard
+ * Test case for the Task Import Wizard.
  * 
  * @author Rob Elves
+ * @author Steffen Pingel
  */
 public class TaskDataImportTest extends AbstractContextTest {
 
@@ -36,9 +36,13 @@ public class TaskDataImportTest extends AbstractContextTest {
 
 	private TaskDataImportWizardPage wizardPage = null;
 
-	private final String sourceZipPath = "testdata/taskdataimporttest/mylardata-2007-01-19.zip";
+	private final String BACKUP_v1 = "testdata/taskdataimporttest/mylardata-2007-01-19.zip";
 
-	private File sourceZipFile = null;
+	private final String BACKUP_v3 = "testdata/taskdataimporttest/mylyn-v3-data-2009-12-09-171942.zip";
+
+	private final String BACKUP_OLD_v3 = "testdata/taskdataimporttest/mylyn-v3-data-2009-12-09-old-tasklist.zip";
+
+	private TaskList taskList;
 
 	@Override
 	protected void setUp() throws Exception {
@@ -52,9 +56,7 @@ public class TaskDataImportTest extends AbstractContextTest {
 		assertNotNull(wizardPage);
 
 		TaskTestUtil.resetTaskListAndRepositories();
-
-		sourceZipFile = TaskTestUtil.getLocalFile(sourceZipPath);
-		assertTrue(sourceZipFile.exists());
+		taskList = TasksUiPlugin.getTaskList();
 
 		ContextCorePlugin.getContextManager().getActivityMetaContext().reset();
 	}
@@ -64,8 +66,7 @@ public class TaskDataImportTest extends AbstractContextTest {
 		wizard.dispose();
 		wizardPage.dispose();
 		ContextCorePlugin.getContextManager().resetActivityMetaContext();
-		TasksUiPlugin.getRepositoryManager().clearRepositories(TasksUiPlugin.getDefault().getRepositoriesFilePath());
-		TaskTestUtil.resetTaskList();
+		TaskTestUtil.resetTaskListAndRepositories();
 		super.tearDown();
 	}
 
@@ -73,14 +74,13 @@ public class TaskDataImportTest extends AbstractContextTest {
 	 * Tests the wizard when it has been asked to import all task data from a zip file
 	 */
 	public void testImportRepositoriesZip() {
-		TaskList taskList = TasksUiPlugin.getTaskList();
 		InteractionContext historyContext = ContextCorePlugin.getContextManager().getActivityMetaContext();
 		assertNotNull(taskList);
 		assertNotNull(historyContext);
 		assertTrue(taskList.getAllTasks().size() == 0);
 		assertTrue(historyContext.getInteractionHistory().size() == 0);
 
-		wizardPage.setSource(true, sourceZipFile.getPath());
+		wizardPage.setSource(true, TaskTestUtil.getLocalFile(BACKUP_v1).getAbsolutePath());
 		wizard.performFinish();
 
 		Collection<AbstractTask> tasks = taskList.getAllTasks();
@@ -95,7 +95,6 @@ public class TaskDataImportTest extends AbstractContextTest {
 	}
 
 	public void testImportOverwritesAllTasks() {
-		TaskList taskList = TasksUiPlugin.getTaskList();
 		InteractionContext historyContext = ContextCorePlugin.getContextManager().getActivityMetaContext();
 		assertNotNull(taskList);
 		assertNotNull(historyContext);
@@ -107,7 +106,7 @@ public class TaskDataImportTest extends AbstractContextTest {
 		Collection<AbstractTask> tasks = taskList.getAllTasks();
 		assertEquals(1, tasks.size());
 
-		wizardPage.setSource(true, sourceZipFile.getPath());
+		wizardPage.setSource(true, TaskTestUtil.getLocalFile(BACKUP_v1).getAbsolutePath());
 		wizard.performFinish();
 
 		tasks = taskList.getAllTasks();
@@ -121,4 +120,23 @@ public class TaskDataImportTest extends AbstractContextTest {
 		assertTrue(historyContext.getInteractionHistory().size() > 0);
 		assertTrue(TasksUiPlugin.getRepositoryManager().getAllRepositories().size() > 2);
 	}
+
+	public void testImportBackupWithOldTaskList() {
+		wizardPage.setSource(true, TaskTestUtil.getLocalFile(BACKUP_OLD_v3).getAbsolutePath());
+		wizard.performFinish();
+
+		Collection<AbstractTask> tasks = taskList.getAllTasks();
+		assertEquals(1, tasks.size());
+		assertEquals("Task 3", tasks.iterator().next().getSummary());
+	}
+
+	public void testImportBackup() {
+		wizardPage.setSource(true, TaskTestUtil.getLocalFile(BACKUP_v3).getAbsolutePath());
+		wizard.performFinish();
+
+		Collection<AbstractTask> tasks = taskList.getAllTasks();
+		assertEquals(1, tasks.size());
+		assertEquals("Task 3", tasks.iterator().next().getSummary());
+	}
+
 }
diff --git a/org.eclipse.mylyn.tasks.tests/testdata/taskdataimporttest/mylyn-v3-data-2009-12-09-171942.zip b/org.eclipse.mylyn.tasks.tests/testdata/taskdataimporttest/mylyn-v3-data-2009-12-09-171942.zip
new file mode 100644
index 000000000..2430c5391
--- /dev/null
+++ b/org.eclipse.mylyn.tasks.tests/testdata/taskdataimporttest/mylyn-v3-data-2009-12-09-171942.zip
diff --git a/org.eclipse.mylyn.tasks.tests/testdata/taskdataimporttest/mylyn-v3-data-2009-12-09-old-tasklist.zip b/org.eclipse.mylyn.tasks.tests/testdata/taskdataimporttest/mylyn-v3-data-2009-12-09-old-tasklist.zip
new file mode 100644
index 000000000..e20bbd07c
--- /dev/null
+++ b/org.eclipse.mylyn.tasks.tests/testdata/taskdataimporttest/mylyn-v3-data-2009-12-09-old-tasklist.zip
diff --git a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/util/TaskDataExportOperation.java b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/util/TaskDataExportOperation.java
index 8ed4403ce..639f6368d 100644
--- a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/util/TaskDataExportOperation.java
+++ b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/util/TaskDataExportOperation.java
@@ -41,9 +41,7 @@ public class TaskDataExportOperation implements IRunnableWithProgress {
 
 	private static final String EXPORT_JOB_LABEL = Messages.TaskDataExportOperation_exporting_task_data;
 
-	private static final Pattern excludeHidden = Pattern.compile("^\\."); //$NON-NLS-1$
-
-	private static final Pattern excludeBackup = Pattern.compile("backup\\z"); //$NON-NLS-1$
+	private static final Pattern excludePattern = Pattern.compile("(?:^\\.|^tasklist.xml.zip\\z|attachments\\z|backup\\z)"); //$NON-NLS-1$
 
 	private final String destinationDirectory;
 
@@ -84,8 +82,7 @@ public class TaskDataExportOperation implements IRunnableWithProgress {
 
 	protected void selectFiles(Set<File> filesToExport) {
 		Set<Pattern> exclusionPatterns = new HashSet<Pattern>();
-		exclusionPatterns.add(excludeHidden);
-		exclusionPatterns.add(excludeBackup);
+		exclusionPatterns.add(excludePattern);
 		String dataRoot = TasksUiPlugin.getDefault().getDataDirectory();
 		File dataFolder = new File(dataRoot);
 		for (File file : dataFolder.listFiles()) {
diff --git a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/wizards/TaskDataImportWizard.java b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/wizards/TaskDataImportWizard.java
index 845ddd053..4c2ae8043 100644
--- a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/wizards/TaskDataImportWizard.java
+++ b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/wizards/TaskDataImportWizard.java
@@ -13,7 +13,6 @@ package org.eclipse.mylyn.internal.tasks.ui.wizards;
 
 import java.io.File;
 import java.io.IOException;
-import com.ibm.icu.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.Enumeration;
 import java.util.Locale;
@@ -44,6 +43,8 @@ import org.eclipse.ui.IImportWizard;
 import org.eclipse.ui.IWorkbench;
 import org.eclipse.ui.PlatformUI;
 
+import com.ibm.icu.text.SimpleDateFormat;
+
 /**
  * @author Rob Elves
  */
@@ -130,24 +131,33 @@ public class TaskDataImportWizard extends Wizard implements IImportWizard {
 
 		private final String JOB_LABEL = Messages.TaskDataImportWizard_Importing_Data;
 
-		private File sourceZipFile = null;
-
-		private int numEntries = 0;
-
-		private boolean restoreM2Tasklist = false;
+		private final File sourceZipFile;
 
 		public FileCopyJob(File sourceZipFile) {
 			this.sourceZipFile = sourceZipFile;
 		}
 
 		public void run(final IProgressMonitor monitor) throws CoreException {
-
 			try {
+				boolean hasDefaultTaskList = false;
+				int numEntries = 0;
 
-				checkZipFile();
+				// determine properties of backup
+				ZipFile zipFile = new ZipFile(sourceZipFile, ZipFile.OPEN_READ);
+				try {
+					Enumeration<? extends ZipEntry> entries = zipFile.entries();
+					while (entries.hasMoreElements()) {
+						ZipEntry entry = entries.nextElement();
+						if (entry.getName().equals(ITasksCoreConstants.DEFAULT_TASK_LIST_FILE)) {
+							hasDefaultTaskList = true;
+						}
+						numEntries++;
+					}
+				} finally {
+					zipFile.close();
+				}
 
 				if (numEntries > 0) {
-
 					monitor.beginTask(JOB_LABEL, numEntries);
 					Job.getJobManager().beginRule(ITasksCoreConstants.ROOT_SCHEDULING_RULE, monitor);
 
@@ -157,28 +167,10 @@ public class TaskDataImportWizard extends Wizard implements IImportWizard {
 
 					ZipFileUtil.unzipFiles(sourceZipFile, TasksUiPlugin.getDefault().getDataDirectory(), monitor);
 
-					if (restoreM2Tasklist) {
-
-						SimpleDateFormat format = new SimpleDateFormat(ITasksCoreConstants.FILENAME_TIMESTAMP_FORMAT,
-								Locale.ENGLISH);
-						String date = format.format(new Date());
-
-						File taskListFile = new File(TasksUiPlugin.getDefault().getDataDirectory(),
-								ITasksCoreConstants.DEFAULT_TASK_LIST_FILE);
-						if (taskListFile.exists()) {
-							taskListFile.renameTo(new File(taskListFile.getParentFile(), taskListFile.getName()
-									+ PREFIX_BACKUP + date));
-						}
-
-						File taskListFileSnapshot = new File(TasksUiPlugin.getDefault().getDataDirectory(),
-								AbstractExternalizationParticipant.SNAPSHOT_PREFIX
-										+ ITasksCoreConstants.DEFAULT_TASK_LIST_FILE);
-						if (taskListFileSnapshot.exists()) {
-							taskListFileSnapshot.renameTo(new File(taskListFile.getParentFile(),
-									taskListFileSnapshot.getName() + PREFIX_BACKUP + date));
-						}
-
+					if (!hasDefaultTaskList) {
+						renameTaskList();
 					}
+
 					readTaskListData();
 				}
 			} catch (IOException e) {
@@ -190,20 +182,26 @@ public class TaskDataImportWizard extends Wizard implements IImportWizard {
 			}
 		}
 
-		private void checkZipFile() throws IOException {
-			Enumeration<? extends ZipEntry> entries;
-			ZipFile zipFile = new ZipFile(sourceZipFile, ZipFile.OPEN_READ);
-			try {
-				entries = zipFile.entries();
-				while (entries.hasMoreElements()) {
-					ZipEntry entry = entries.nextElement();
-					if (entry.getName().startsWith(ITasksCoreConstants.OLD_TASK_LIST_FILE)) {
-						restoreM2Tasklist = true;
-					}
-					numEntries++;
-				}
-			} finally {
-				zipFile.close();
+		/**
+		 * Rename existing task list file to avoid loading that instead of the restored old one.
+		 */
+		private void renameTaskList() {
+			SimpleDateFormat format = new SimpleDateFormat(ITasksCoreConstants.FILENAME_TIMESTAMP_FORMAT,
+					Locale.ENGLISH);
+			String date = format.format(new Date());
+
+			File taskListFile = new File(TasksUiPlugin.getDefault().getDataDirectory(),
+					ITasksCoreConstants.DEFAULT_TASK_LIST_FILE);
+			if (taskListFile.exists()) {
+				taskListFile.renameTo(new File(taskListFile.getParentFile(), taskListFile.getName() + PREFIX_BACKUP
+						+ date));
+			}
+
+			File taskListFileSnapshot = new File(TasksUiPlugin.getDefault().getDataDirectory(),
+					AbstractExternalizationParticipant.SNAPSHOT_PREFIX + ITasksCoreConstants.DEFAULT_TASK_LIST_FILE);
+			if (taskListFileSnapshot.exists()) {
+				taskListFileSnapshot.renameTo(new File(taskListFile.getParentFile(), taskListFileSnapshot.getName()
+						+ PREFIX_BACKUP + date));
 			}
 		}