diff -r 000000000000 -r 6474c204b198 toolkit/components/places/tests/bookmarks/test_818584-discard-duplicate-backups.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/places/tests/bookmarks/test_818584-discard-duplicate-backups.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,59 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Checks that automatically created bookmark backups are discarded if they are
+ * duplicate of an existing ones.
+ */
+function run_test() {
+  run_next_test();
+}
+
+add_task(function() {
+  // Create a backup for yesterday in the backups folder.
+  let backupFolder = yield PlacesBackups.getBackupFolder();
+  let dateObj = new Date();
+  dateObj.setDate(dateObj.getDate() - 1);
+  let oldBackupName = PlacesBackups.getFilenameForDate(dateObj);
+  let oldBackup = OS.Path.join(backupFolder, oldBackupName);
+  let {count: count, hash: hash} = yield BookmarkJSONUtils.exportToFile(oldBackup);
+  do_check_true(count > 0);
+  do_check_eq(hash.length, 24);
+  oldBackupName = oldBackupName.replace(/\.json/, "_" + count + "_" + hash + ".json");
+  yield OS.File.move(oldBackup, OS.Path.join(backupFolder, oldBackupName));
+
+  // Create a backup.
+  // This should just rename the existing backup, so in the end there should be
+  // only one backup with today's date.
+  yield PlacesBackups.create();
+
+  // Get the hash of the generated backup
+  let backupFiles = yield PlacesBackups.getBackupFiles();
+  do_check_eq(backupFiles.length, 1);
+  
+  let matches = OS.Path.basename(backupFiles[0]).match(PlacesBackups.filenamesRegex);
+  do_check_eq(matches[1], new Date().toLocaleFormat("%Y-%m-%d"));
+  do_check_eq(matches[2], count);
+  do_check_eq(matches[3], hash);
+
+  // Add a bookmark and create another backup.
+  let bookmarkId = PlacesUtils.bookmarks.insertBookmark(PlacesUtils.bookmarks.bookmarksMenuFolder,
+                                                        uri("http://foo.com"),
+                                                        PlacesUtils.bookmarks.DEFAULT_INDEX,
+                                                        "foo");
+  // We must enforce a backup since one for today already exists.  The forced
+  // backup will replace the existing one.
+  yield PlacesBackups.create(undefined, true);
+  do_check_eq(backupFiles.length, 1);
+  recentBackup = yield PlacesBackups.getMostRecentBackup();
+  do_check_neq(recentBackup, OS.Path.join(backupFolder, oldBackupName));
+  matches = OS.Path.basename(recentBackup).match(PlacesBackups.filenamesRegex);
+  do_check_eq(matches[1], new Date().toLocaleFormat("%Y-%m-%d"));
+  do_check_eq(matches[2], count + 1);
+  do_check_neq(matches[3], hash);
+
+  // Clean up
+  PlacesUtils.bookmarks.removeItem(bookmarkId);
+  yield PlacesBackups.create(0);
+});