diff -r 000000000000 -r 6474c204b198 toolkit/components/satchel/test/unit/test_db_update_v999a.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/satchel/test/unit/test_db_update_v999a.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,75 @@
+/* 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/. */
+
+/*
+ * This test uses a formhistory.sqlite with schema version set to 999 (a
+ * future version). This exercies the code that allows using a future schema
+ * version as long as the expected columns are present.
+ *
+ * Part A tests this when the columns do match, so the DB is used.
+ * Part B tests this when the columns do *not* match, so the DB is reset.
+ */
+
+let iter = tests();
+
+function run_test()
+{
+  do_test_pending();
+  iter.next();
+}
+
+function next_test()
+{
+  iter.next();
+}
+
+function tests()
+{
+  try {
+  var testnum = 0;
+
+  // ===== test init =====
+  var testfile = do_get_file("formhistory_v999a.sqlite");
+  var profileDir = dirSvc.get("ProfD", Ci.nsIFile);
+
+  // Cleanup from any previous tests or failures.
+  var destFile = profileDir.clone();
+  destFile.append("formhistory.sqlite");
+  if (destFile.exists())
+    destFile.remove(false);
+
+  testfile.copyTo(profileDir, "formhistory.sqlite");
+  do_check_eq(999, getDBVersion(testfile));
+
+  let checkZero = function(num) { do_check_eq(num, 0); next_test(); }
+  let checkOne = function(num) { do_check_eq(num, 1); next_test(); }
+
+  // ===== 1 =====
+  testnum++;
+  // Check for expected contents.
+  yield countEntries(null, null, function(num) { do_check_true(num > 0); next_test(); });
+  yield countEntries("name-A", "value-A", checkOne);
+  yield countEntries("name-B", "value-B", checkOne);
+  yield countEntries("name-C", "value-C1", checkOne);
+  yield countEntries("name-C", "value-C2", checkOne);
+  yield countEntries("name-E", "value-E", checkOne);
+
+  // check for downgraded schema.
+  do_check_eq(CURRENT_SCHEMA, FormHistory.schemaVersion);
+
+  // ===== 2 =====
+  testnum++;
+  // Exercise adding and removing a name/value pair
+  yield countEntries("name-D", "value-D", checkZero);
+  yield updateEntry("add", "name-D", "value-D", next_test);
+  yield countEntries("name-D", "value-D", checkOne);
+  yield updateEntry("remove", "name-D", "value-D", next_test);
+  yield countEntries("name-D", "value-D", checkZero);
+
+  } catch (e) {
+    throw "FAILED in test #" + testnum + " -- " + e;
+  }
+
+  do_test_finished();
+}