From 5e3a39cb69af62326b25202a387bbeb52e6b3e38 Mon Sep 17 00:00:00 2001
From: Clark Fischer <clark.fischer@gmail.com>
Date: Mon, 9 Jan 2023 20:21:09 -0800
Subject: [PATCH] Allow IndexedDB cleanup operations to fail

Firefox ships with a preference (`dom.indexedDB.privateBrowsing.enabled`) which
causes `window.indexedDB` to fail on all requests including `deleteDatabase`.
Because of that, Firefox Private Browsing users are left with an infinite
loading spinner.

`MatrixClient#clearStores` will resolve to a rejected promise if any of its
operations fails, which seems correct -- it's unable to complete its tasks.
So, to keep from erroring out during initialization, the errors have to be
discarded during the lifecycle operations.

Signed-off-by: Clark Fischer <clark.fischer@gmail.com>
---
 src/Lifecycle.ts       | 10 ++++++++--
 test/Lifecycle-test.ts | 44 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 2 deletions(-)
 create mode 100644 test/Lifecycle-test.ts

diff --git a/src/Lifecycle.ts b/src/Lifecycle.ts
index 30aab429fb7..b1e3eb1b896 100644
--- a/src/Lifecycle.ts
+++ b/src/Lifecycle.ts
@@ -2,7 +2,7 @@
 Copyright 2015, 2016 OpenMarket Ltd
 Copyright 2017 Vector Creations Ltd
 Copyright 2018 New Vector Ltd
-Copyright 2019, 2020 The Matrix.org Foundation C.I.C.
+Copyright 2019 - 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -926,7 +926,13 @@ async function clearStorage(opts?: { deleteEverything?: boolean }): Promise<void
     });
 
     await EventIndexPeg.deleteEventIndex();
-    await cli.clearStores();
+    try {
+        await cli.clearStores();
+    } catch (_) {
+        // Clearing the stores failed, which is probably okay, they were
+        // supposed to be cleared anyway. Any relevant errors were already
+        // logged.
+    }
 }
 
 /**
diff --git a/test/Lifecycle-test.ts b/test/Lifecycle-test.ts
new file mode 100644
index 00000000000..e445bfb49bb
--- /dev/null
+++ b/test/Lifecycle-test.ts
@@ -0,0 +1,44 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import * as Lifecycle from "../src/Lifecycle";
+import { mockPlatformPeg } from "./test-utils";
+
+/**
+ * Create a fake IndexedDB that mimics Firefox's 'disabled' implementation.
+ */
+function brokenIDB(): IDBFactory {
+    return {
+        deleteDatabase: () => {
+            // Return an IDBOpenDBRequest that immediately errors
+            const resp = { onerror: undefined } as IDBOpenDBRequest;
+            setTimeout(() => resp.onerror?.(new ErrorEvent("")), 1);
+            return resp;
+        },
+    } as unknown as IDBFactory;
+}
+
+describe("Lifecycle", () => {
+    describe("onLoggedOut", () => {
+        beforeAll(() => mockPlatformPeg());
+
+        it("allows IndexedDB failures", async () => {
+            // Ensure that the indexedDB error is not propagated.
+            globalThis.indexedDB = brokenIDB();
+            await Lifecycle.onLoggedOut();
+        });
+    });
+});