Always revalidate desktop updates before install

docs/release.md

@@ -169,13 +169,13 @@ This does **not** apply to fresh releases cut via `npm run release:patch` — th
 
 ### Releasing during an active rollout
 
-If you ship N+1 while N is still ramping, N+1 starts a fresh rollout from its own publish timestamp. N's rollout effectively ends — the newer manifest supersedes it.
+If you ship N+1 while N is still ramping, N+1 starts a fresh rollout from its own publish timestamp. N's rollout effectively ends — the newer manifest supersedes it. Rollout-aware clients revalidate the manifest before installing a downloaded update on quit. If N+1 has replaced N but the client is not admitted to N+1 yet, it skips the downloaded N and waits rather than installing two updates in succession.
 
 If N+1 is a hotfix for a bug in N, dispatch `desktop-rollout.yml -f tag=v0.1.<N+1> -f rollout_hours=0` after N+1 publishes so the users who already got N reach the fix fast.
 
 ### Limitations
 
-- **No pause / kill switch.** Once a stable user is admitted, they will install the update on next quit (`autoInstallOnAppQuit = true`). To stop new admissions, ship a superseding release. To "recall" already-admitted users, ship a hotfix `+1` patch.
+- **No pause / kill switch.** To stop new admissions, ship a superseding release. Clients revalidate on quit and will not install the superseded download, but a client that already completed installation cannot be recalled; ship a hotfix `+1` patch.
 - **No rollback.** `allowDowngrade = false`. Bad release = ship a hotfix.
 - **Bootstrap caveat.** Clients running a build older than the rollout feature ignore `rolloutHours` and admit immediately. Rollout protection only applies to clients running the rollout-aware version or later.
 - **Up to ~30 min automatic admission latency.** Renderer polls every 30 minutes, so a stable user may take up to that long to be evaluated against the rollout window. Clicking **Check** is manual and bypasses rollout admission.

packages/desktop/src/daemon/quit-lifecycle.test.ts

@@ -1,4 +1,4 @@
-import { describe, expect, it, vi } from "vitest";
+import { describe, expect, it } from "vitest";
 
 import { DEFAULT_DESKTOP_SETTINGS } from "../settings/desktop-settings";
 import {
@@ -23,96 +23,151 @@ describe("quit-lifecycle", () => {
   });
 
   it("short-circuits without inspecting the daemon when keep-running is on", async () => {
-    const isDesktopManagedDaemonRunning = vi.fn(() => true);
-    const stopDaemon = vi.fn(async () => undefined);
-    const showShutdownFeedback = vi.fn();
+    const events: string[] = [];
 
     const stopped = await stopDesktopManagedDaemonOnQuitIfNeeded({
       settingsStore: { get: async () => SETTINGS_KEEP_RUNNING },
-      isDesktopManagedDaemonRunning,
-      stopDaemon,
-      showShutdownFeedback,
+      isDesktopManagedDaemonRunning: () => {
+        events.push("inspect");
+        return true;
+      },
+      stopDaemon: async () => {
+        events.push("stop");
+      },
+      showShutdownFeedback: () => {
+        events.push("feedback");
+      },
     });
 
     expect(stopped).toBe(false);
-    expect(isDesktopManagedDaemonRunning).not.toHaveBeenCalled();
-    expect(stopDaemon).not.toHaveBeenCalled();
-    expect(showShutdownFeedback).not.toHaveBeenCalled();
+    expect(events).toEqual([]);
   });
 
   it("does not stop a manually started daemon on quit", async () => {
-    const stopDaemon = vi.fn(async () => undefined);
-    const showShutdownFeedback = vi.fn();
+    const events: string[] = [];
 
     const stopped = await stopDesktopManagedDaemonOnQuitIfNeeded({
       settingsStore: { get: async () => SETTINGS_STOP_ON_QUIT },
       isDesktopManagedDaemonRunning: () => false,
-      stopDaemon,
-      showShutdownFeedback,
+      stopDaemon: async () => {
+        events.push("stop");
+      },
+      showShutdownFeedback: () => {
+        events.push("feedback");
+      },
     });
 
     expect(stopped).toBe(false);
-    expect(stopDaemon).not.toHaveBeenCalled();
-    expect(showShutdownFeedback).not.toHaveBeenCalled();
+    expect(events).toEqual([]);
   });
 
   it("shows feedback then stops a desktop-managed daemon", async () => {
-    const stopDaemon = vi.fn(async () => undefined);
-    const showShutdownFeedback = vi.fn();
+    const events: string[] = [];
 
     const stopped = await stopDesktopManagedDaemonOnQuitIfNeeded({
       settingsStore: { get: async () => SETTINGS_STOP_ON_QUIT },
       isDesktopManagedDaemonRunning: () => true,
-      stopDaemon,
-      showShutdownFeedback,
+      stopDaemon: async () => {
+        events.push("stop");
+      },
+      showShutdownFeedback: () => {
+        events.push("feedback");
+      },
     });
 
     expect(stopped).toBe(true);
-    expect(showShutdownFeedback).toHaveBeenCalledTimes(1);
-    expect(stopDaemon).toHaveBeenCalledTimes(1);
-    expect(showShutdownFeedback.mock.invocationCallOrder[0]).toBeLessThan(
-      stopDaemon.mock.invocationCallOrder[0],
-    );
+    expect(events).toEqual(["feedback", "stop"]);
   });
 
-  it("preventDefaults the first quit, runs the async stop decision, then exits hard", async () => {
+  it("revalidates updates after daemon shutdown before exiting", async () => {
     let resolveStopDecision: (() => void) | null = null;
-    const app = { exit: vi.fn() };
-    const closeTransportSessions = vi.fn();
-    const onStopError = vi.fn();
-    const preventDefault = vi.fn();
-    const secondPreventDefault = vi.fn();
+    let resolveUpdateDecision: (() => void) | null = null;
+    const events: string[] = [];
 
     const handleBeforeQuit = createBeforeQuitHandler({
-      app,
-      closeTransportSessions,
-      stopDesktopManagedDaemonIfNeeded: vi.fn(
-        () =>
-          new Promise<boolean>((resolve) => {
-            resolveStopDecision = () => resolve(false);
-          }),
-      ),
-      onStopError,
+      app: {
+        exit: (code) => {
+          events.push(`exit:${code}`);
+        },
+      },
+      closeTransportSessions: () => {
+        events.push("close-transports");
+      },
+      stopDesktopManagedDaemonIfNeeded: () =>
+        new Promise<boolean>((resolve) => {
+          resolveStopDecision = () => {
+            events.push("daemon-stopped");
+            resolve(false);
+          };
+        }),
+      installAppUpdateOnQuit: () =>
+        new Promise<boolean>((resolve) => {
+          resolveUpdateDecision = () => {
+            events.push("update-checked");
+            resolve(false);
+          };
+        }),
+      onStopError: () => {
+        events.push("stop-error");
+      },
+      onUpdateError: () => {
+        events.push("update-error");
+      },
     });
 
-    handleBeforeQuit({ preventDefault });
+    handleBeforeQuit({
+      preventDefault: () => {
+        events.push("prevent-default");
+      },
+    });
 
-    expect(preventDefault).toHaveBeenCalledTimes(1);
-    expect(closeTransportSessions).toHaveBeenCalledTimes(1);
-    expect(app.exit).not.toHaveBeenCalled();
+    expect(events).toEqual(["close-transports", "prevent-default"]);
     expect(resolveStopDecision).not.toBeNull();
 
     resolveStopDecision?.();
     await Promise.resolve();
     await Promise.resolve();
 
-    expect(app.exit).toHaveBeenCalledWith(0);
-    expect(onStopError).not.toHaveBeenCalled();
+    expect(events).toEqual(["close-transports", "prevent-default", "daemon-stopped"]);
+    expect(resolveUpdateDecision).not.toBeNull();
 
-    handleBeforeQuit({ preventDefault: secondPreventDefault });
+    resolveUpdateDecision?.();
+    await Promise.resolve();
+    await Promise.resolve();
 
-    expect(secondPreventDefault).not.toHaveBeenCalled();
-    expect(closeTransportSessions).toHaveBeenCalledTimes(2);
-    expect(app.exit).toHaveBeenCalledTimes(1);
+    expect(events).toEqual([
+      "close-transports",
+      "prevent-default",
+      "daemon-stopped",
+      "update-checked",
+      "exit:0",
+    ]);
+
+    handleBeforeQuit({
+      preventDefault: () => {
+        events.push("second-prevent-default");
+      },
+    });
+
+    expect(events.at(-1)).toBe("close-transports");
+    expect(events).not.toContain("second-prevent-default");
+  });
+
+  it("lets the updater own process exit when a validated update is installing", async () => {
+    const exits: number[] = [];
+    const handleBeforeQuit = createBeforeQuitHandler({
+      app: { exit: (code) => exits.push(code) },
+      closeTransportSessions: () => {},
+      stopDesktopManagedDaemonIfNeeded: async () => false,
+      installAppUpdateOnQuit: async () => true,
+      onStopError: () => {},
+      onUpdateError: () => {},
+    });
+
+    handleBeforeQuit({ preventDefault: () => {} });
+    await Promise.resolve();
+    await Promise.resolve();
+
+    expect(exits).toEqual([]);
   });
 });

packages/desktop/src/daemon/quit-lifecycle.ts

@@ -46,18 +46,20 @@ export function createBeforeQuitHandler({
   app,
   closeTransportSessions,
   stopDesktopManagedDaemonIfNeeded,
+  installAppUpdateOnQuit,
   onStopError,
+  onUpdateError,
 }: {
   app: BeforeQuitApp;
   closeTransportSessions: () => void;
   stopDesktopManagedDaemonIfNeeded: () => Promise<boolean>;
+  installAppUpdateOnQuit: () => Promise<boolean>;
   onStopError: (error: unknown) => void;
+  onUpdateError: (error: unknown) => void;
 }): (event: BeforeQuitEvent) => void {
-  // We always preventDefault on first quit so we can run the async stop
-  // decision, then call app.exit(0) — which bypasses Electron's
-  // close → window-all-closed → will-quit chain. The window-all-closed
-  // listener is a darwin no-op (macOS convention) and would otherwise
-  // veto a re-fired app.quit().
+  // The first quit waits for daemon shutdown and update revalidation. A validated
+  // update re-fires app.quit(); otherwise app.exit(0) bypasses Electron's macOS
+  // window-all-closed handler, which would veto that second quit.
   let quitting = false;
 
   return (event) => {
@@ -66,12 +68,23 @@ export function createBeforeQuitHandler({
     quitting = true;
     event.preventDefault();
 
-    void stopDesktopManagedDaemonIfNeeded()
-      .catch((error) => {
+    void (async () => {
+      try {
+        await stopDesktopManagedDaemonIfNeeded();
+      } catch (error) {
         onStopError(error);
-      })
-      .finally(() => {
-        app.exit(0);
-      });
+      }
+
+      try {
+        const installingUpdate = await installAppUpdateOnQuit();
+        if (installingUpdate) {
+          return;
+        }
+      } catch (error) {
+        onUpdateError(error);
+      }
+
+      app.exit(0);
+    })();
   };
 }

packages/desktop/src/features/app-update-service.test.ts

@@ -17,7 +17,10 @@ class FakeAppUpdateRuntime implements AppUpdateRuntime {
   > = [];
   private gate: ((info: RuntimeUpdateInfo) => boolean | Promise<boolean>) | null = null;
   private configuration: AppUpdateRuntimeConfiguration | null = null;
+  private downloadableUpdate: RuntimeUpdateInfo | null = null;
+  private downloadedUpdate: RuntimeUpdateInfo | null = null;
   checkCount = 0;
+  installedVersions: string[] = [];
 
   configure(input: AppUpdateRuntimeConfiguration): void {
     this.configuration = input;
@@ -59,6 +62,7 @@ class FakeAppUpdateRuntime implements AppUpdateRuntime {
   }
 
   finishUpdateDownload(info: RuntimeUpdateInfo): void {
+    this.downloadedUpdate = info;
     this.configuration?.onUpdateDownloaded(info);
   }
 
@@ -80,12 +84,22 @@ class FakeAppUpdateRuntime implements AppUpdateRuntime {
     }
     if (!result || !this.gate) return result;
     const admitted = await this.gate(result.updateInfo);
-    return { ...result, isUpdateAvailable: result.isUpdateAvailable && admitted };
+    const isUpdateAvailable = result.isUpdateAvailable && admitted;
+    this.downloadableUpdate = isUpdateAvailable ? result.updateInfo : null;
+    return { ...result, isUpdateAvailable };
   }
 
-  async downloadUpdate(): Promise<void> {}
+  async downloadUpdate(): Promise<void> {
+    if (this.downloadableUpdate) {
+      this.finishUpdateDownload(this.downloadableUpdate);
+    }
+  }
 
-  quitAndInstall(): void {}
+  quitAndInstall(): void {
+    if (this.downloadedUpdate) {
+      this.installedVersions.push(this.downloadedUpdate.version);
+    }
+  }
 }
 
 function createService(input?: { now?: () => number; bucket?: () => Promise<number> }) {
@@ -179,6 +193,111 @@ describe("app update service", () => {
     });
   });
 
+  it("replaces a downloaded update when a newer release is admitted", async () => {
+    const { runtime, service } = createService({ bucket: async () => 0 });
+    runtime.nextCheck({ isUpdateAvailable: true, updateInfo: rolledOutUpdate });
+
+    await service.checkForAppUpdate({
+      currentVersion: "1.2.3",
+      releaseChannel: "stable",
+      intent: "automatic",
+    });
+    runtime.finishUpdateDownload(rolledOutUpdate);
+
+    const newerUpdate = { ...rolledOutUpdate, version: "1.2.5" };
+    runtime.nextCheck({ isUpdateAvailable: true, updateInfo: newerUpdate });
+    const result = await service.checkForAppUpdate({
+      currentVersion: "1.2.3",
+      releaseChannel: "stable",
+      intent: "automatic",
+    });
+
+    expect(result).toEqual({
+      hasUpdate: true,
+      readyToInstall: false,
+      currentVersion: "1.2.3",
+      latestVersion: "1.2.5",
+      body: null,
+      date: "2026-04-28T00:00:00.000Z",
+      errorMessage: null,
+    });
+  });
+
+  it("installs the newest admitted release when quitting with an older download", async () => {
+    const { runtime, service } = createService({ bucket: async () => 0 });
+    runtime.nextCheck({ isUpdateAvailable: true, updateInfo: rolledOutUpdate });
+
+    await service.checkForAppUpdate({
+      currentVersion: "1.2.3",
+      releaseChannel: "stable",
+      intent: "automatic",
+    });
+    runtime.finishUpdateDownload(rolledOutUpdate);
+
+    const newerUpdate = { ...rolledOutUpdate, version: "1.2.5" };
+    runtime.nextCheck({ isUpdateAvailable: true, updateInfo: newerUpdate });
+    const installed = await service.installUpdateOnQuit({
+      currentVersion: "1.2.3",
+      releaseChannel: "stable",
+    });
+
+    expect(installed).toBe(true);
+    expect(runtime.installedVersions).toEqual(["1.2.5"]);
+  });
+
+  it("does not install an older download while its replacement is still rolling out", async () => {
+    const now = Date.parse("2026-04-28T12:00:00.000Z");
+    const { runtime, service } = createService({ now: () => now, bucket: async () => 0.4 });
+    const olderUpdate = {
+      ...rolledOutUpdate,
+      releaseDate: "2026-04-27T00:00:00.000Z",
+    };
+    runtime.nextCheck({ isUpdateAvailable: true, updateInfo: olderUpdate });
+
+    await service.checkForAppUpdate({
+      currentVersion: "1.2.3",
+      releaseChannel: "stable",
+      intent: "automatic",
+    });
+    runtime.finishUpdateDownload(olderUpdate);
+
+    const newerUpdate = {
+      ...rolledOutUpdate,
+      version: "1.2.5",
+      releaseDate: "2026-04-28T12:00:00.000Z",
+    };
+    runtime.nextCheck({ isUpdateAvailable: true, updateInfo: newerUpdate });
+    const installed = await service.installUpdateOnQuit({
+      currentVersion: "1.2.3",
+      releaseChannel: "stable",
+    });
+
+    expect(installed).toBe(false);
+    expect(runtime.installedVersions).toEqual([]);
+  });
+
+  it("rechecks for the newest release before a manual install", async () => {
+    const { runtime, service } = createService({ bucket: async () => 0.99 });
+    runtime.nextCheck({ isUpdateAvailable: true, updateInfo: rolledOutUpdate });
+
+    await service.checkForAppUpdate({
+      currentVersion: "1.2.3",
+      releaseChannel: "stable",
+      intent: "manual",
+    });
+    runtime.finishUpdateDownload(rolledOutUpdate);
+
+    const newerUpdate = { ...rolledOutUpdate, version: "1.2.5" };
+    runtime.nextCheck({ isUpdateAvailable: true, updateInfo: newerUpdate });
+    const result = await service.downloadAndInstallUpdate({
+      currentVersion: "1.2.3",
+      releaseChannel: "stable",
+    });
+
+    expect(result.installed).toBe(true);
+    expect(runtime.installedVersions).toEqual(["1.2.5"]);
+  });
+
   it("trusts the runtime availability decision before comparing versions", async () => {
     const { runtime, service } = createService({ bucket: async () => 0 });
     runtime.nextCheck({ isUpdateAvailable: false, updateInfo: rolledOutUpdate });
@@ -322,40 +441,8 @@ describe("app update service", () => {
     });
   });
 
-  it("keeps preparation errors emitted before the update check rejects", async () => {
-    const { runtime, service } = createService();
-    const deferredCheck = runtime.deferNextCheck();
-    const pending = service.checkForAppUpdate({
-      currentVersion: "1.2.3",
-      releaseChannel: "stable",
-      intent: "automatic",
-    });
-
-    runtime.prepareUpdate(rolledOutUpdate);
-    runtime.failRuntime(new Error("sha512 checksum mismatch"));
-    deferredCheck.reject(new Error("sha512 checksum mismatch"));
-    const checkResult = await pending;
-    expect(checkResult.errorMessage).toBe("sha512 checksum mismatch");
-
-    const automaticResult = await service.checkForAppUpdate({
-      currentVersion: "1.2.3",
-      releaseChannel: "stable",
-      intent: "automatic",
-    });
-
-    expect(automaticResult).toEqual({
-      hasUpdate: true,
-      readyToInstall: false,
-      currentVersion: "1.2.3",
-      latestVersion: "1.2.4",
-      body: null,
-      date: "2026-04-28T00:00:00.000Z",
-      errorMessage: "sha512 checksum mismatch",
-    });
-  });
-
-  it("returns runtime update errors after an update fails to prepare", async () => {
-    const { runtime, service } = createService();
+  it("discovers newer releases after an update fails to prepare", async () => {
+    const { runtime, service } = createService({ bucket: async () => 0 });
     runtime.nextCheck({ isUpdateAvailable: true, updateInfo: rolledOutUpdate });
 
     await service.checkForAppUpdate({
@@ -365,6 +452,8 @@ describe("app update service", () => {
     });
     runtime.failRuntime(new Error("sha512 checksum mismatch"));
 
+    const newerUpdate = { ...rolledOutUpdate, version: "1.2.5" };
+    runtime.nextCheck({ isUpdateAvailable: true, updateInfo: newerUpdate });
     const result = await service.checkForAppUpdate({
       currentVersion: "1.2.3",
       releaseChannel: "stable",
@@ -375,10 +464,10 @@ describe("app update service", () => {
       hasUpdate: true,
       readyToInstall: false,
       currentVersion: "1.2.3",
-      latestVersion: "1.2.4",
+      latestVersion: "1.2.5",
       body: null,
       date: "2026-04-28T00:00:00.000Z",
-      errorMessage: "sha512 checksum mismatch",
+      errorMessage: null,
     });
   });
 
@@ -445,91 +534,4 @@ describe("app update service", () => {
       errorMessage: null,
     });
   });
-
-  it("returns runtime update errors to multiple automatic checks before a manual retry clears them", async () => {
-    const { runtime, service } = createService();
-    runtime.nextCheck({ isUpdateAvailable: true, updateInfo: rolledOutUpdate });
-
-    await service.checkForAppUpdate({
-      currentVersion: "1.2.3",
-      releaseChannel: "stable",
-      intent: "manual",
-    });
-    runtime.failRuntime(new Error("sha512 checksum mismatch"));
-
-    const firstAutomaticResult = await service.checkForAppUpdate({
-      currentVersion: "1.2.3",
-      releaseChannel: "stable",
-      intent: "automatic",
-    });
-    const secondAutomaticResult = await service.checkForAppUpdate({
-      currentVersion: "1.2.3",
-      releaseChannel: "stable",
-      intent: "automatic",
-    });
-
-    expect(firstAutomaticResult).toEqual({
-      hasUpdate: true,
-      readyToInstall: false,
-      currentVersion: "1.2.3",
-      latestVersion: "1.2.4",
-      body: null,
-      date: "2026-04-28T00:00:00.000Z",
-      errorMessage: "sha512 checksum mismatch",
-    });
-    expect(secondAutomaticResult).toEqual(firstAutomaticResult);
-
-    runtime.nextCheck(null);
-    const retryResult = await service.checkForAppUpdate({
-      currentVersion: "1.2.3",
-      releaseChannel: "stable",
-      intent: "manual",
-    });
-
-    expect(runtime.checkCount).toBe(2);
-    expect(retryResult).toEqual({
-      hasUpdate: false,
-      readyToInstall: false,
-      currentVersion: "1.2.3",
-      latestVersion: "1.2.3",
-      body: null,
-      date: null,
-      errorMessage: null,
-    });
-  });
-
-  it("keeps runtime update errors visible after a manual retry fails", async () => {
-    const { runtime, service } = createService();
-    runtime.nextCheck({ isUpdateAvailable: true, updateInfo: rolledOutUpdate });
-
-    await service.checkForAppUpdate({
-      currentVersion: "1.2.3",
-      releaseChannel: "stable",
-      intent: "manual",
-    });
-    runtime.failRuntime(new Error("sha512 checksum mismatch"));
-
-    runtime.failNextCheck(new Error("network down"));
-    const retryResult = await service.checkForAppUpdate({
-      currentVersion: "1.2.3",
-      releaseChannel: "stable",
-      intent: "manual",
-    });
-    const automaticResult = await service.checkForAppUpdate({
-      currentVersion: "1.2.3",
-      releaseChannel: "stable",
-      intent: "automatic",
-    });
-
-    expect(retryResult.errorMessage).toBe("network down");
-    expect(automaticResult).toEqual({
-      hasUpdate: true,
-      readyToInstall: false,
-      currentVersion: "1.2.3",
-      latestVersion: "1.2.4",
-      body: null,
-      date: "2026-04-28T00:00:00.000Z",
-      errorMessage: "sha512 checksum mismatch",
-    });
-  });
 });

packages/desktop/src/features/app-update-service.ts

@@ -62,6 +62,10 @@ export interface AppUpdateService {
     },
     onBeforeQuit?: () => Promise<void>,
   ): Promise<AppUpdateInstallResult>;
+  installUpdateOnQuit(input: {
+    currentVersion: string;
+    releaseChannel: AppReleaseChannel;
+  }): Promise<boolean>;
 }
 
 export interface AppUpdateServiceDeps {
@@ -112,10 +116,7 @@ function getErrorMessage(error: unknown): string {
 export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateService {
   let cachedUpdateInfo: RuntimeUpdateInfo | null = null;
   let downloadedUpdateVersion: string | null = null;
-  let downloading = false;
   let configuredReleaseChannel: AppReleaseChannel | null = null;
-  let runtimeErrorMessage: string | null = null;
-  let inFlightUpdateCheckCount = 0;
 
   function isReadyToInstallVersion(version: string): boolean {
     return downloadedUpdateVersion === version;
@@ -124,23 +125,6 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
   function clearUpdateState(): void {
     cachedUpdateInfo = null;
     downloadedUpdateVersion = null;
-    downloading = false;
-    runtimeErrorMessage = null;
-  }
-
-  function buildRuntimeErrorResult(currentVersion: string): AppUpdateCheckResult | null {
-    if (!runtimeErrorMessage) {
-      return null;
-    }
-
-    const info = cachedUpdateInfo;
-    return buildCheckResult({
-      currentVersion,
-      hasUpdate: info?.version !== undefined && info.version !== currentVersion,
-      readyToInstall: false,
-      info,
-      errorMessage: runtimeErrorMessage,
-    });
   }
 
   function configureRuntime(releaseChannel: AppReleaseChannel, intent: AppUpdateCheckIntent): void {
@@ -166,23 +150,15 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
         const alreadyReady = downloadedUpdateVersion === info.version;
         cachedUpdateInfo = info;
         downloadedUpdateVersion = alreadyReady ? info.version : null;
-        downloading = !alreadyReady;
-        runtimeErrorMessage = null;
       },
       onUpdateDownloaded(info) {
         cachedUpdateInfo = info;
         downloadedUpdateVersion = info.version;
-        downloading = false;
-        runtimeErrorMessage = null;
       },
       onUpdateNotAvailable() {
         clearUpdateState();
       },
       onError(error) {
-        downloading = false;
-        if (inFlightUpdateCheckCount === 0 || cachedUpdateInfo) {
-          runtimeErrorMessage = getErrorMessage(error);
-        }
         deps.reportRuntimeError?.(error);
       },
     });
@@ -207,28 +183,7 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
 
     configureRuntime(releaseChannel, intent);
 
-    const runtimeErrorResult = buildRuntimeErrorResult(currentVersion);
-    if (runtimeErrorResult && intent === "automatic") {
-      return runtimeErrorResult;
-    }
-
-    const cachedVersion = cachedUpdateInfo?.version ?? null;
-    if (
-      !runtimeErrorResult &&
-      intent === "automatic" &&
-      cachedVersion &&
-      cachedVersion !== currentVersion
-    ) {
-      return buildCheckResult({
-        currentVersion,
-        hasUpdate: true,
-        readyToInstall: isReadyToInstallVersion(cachedVersion),
-        info: cachedUpdateInfo,
-      });
-    }
-
     try {
-      inFlightUpdateCheckCount += 1;
       const result = await deps.runtime.checkForUpdates();
       if (!result || !result.updateInfo || !result.isUpdateAvailable) {
         clearUpdateState();
@@ -245,8 +200,6 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
 
       if (hasUpdate) {
         cachedUpdateInfo = info;
-        downloading = !isReadyToInstallVersion(latestVersion);
-        runtimeErrorMessage = null;
         return buildCheckResult({
           currentVersion,
           hasUpdate: true,
@@ -269,8 +222,6 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
         readyToInstall: false,
         errorMessage: getErrorMessage(error),
       });
-    } finally {
-      inFlightUpdateCheckCount -= 1;
     }
   }
 
@@ -292,6 +243,26 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
       };
     }
 
+    const check = await checkForAppUpdate({
+      currentVersion,
+      releaseChannel,
+      intent: "manual",
+    });
+    if (!check.hasUpdate) {
+      return {
+        installed: false,
+        version: currentVersion,
+        message: check.errorMessage ?? "No update available.",
+      };
+    }
+
+    return installCachedUpdate(currentVersion, onBeforeQuit);
+  }
+
+  async function installCachedUpdate(
+    currentVersion: string,
+    onBeforeQuit?: () => Promise<void>,
+  ): Promise<AppUpdateInstallResult> {
     if (!cachedUpdateInfo) {
       return {
         installed: false,
@@ -300,8 +271,6 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
       };
     }
 
-    configureRuntime(releaseChannel, "manual");
-
     const readyVersion = cachedUpdateInfo.version;
     if (isReadyToInstallVersion(readyVersion)) {
       await performQuitAndInstall(deps.runtime, onBeforeQuit);
@@ -312,20 +281,16 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
       };
     }
 
-    if (downloading) {
-      return {
-        installed: false,
-        version: currentVersion,
-        message: "Update is still being prepared. Try again in a moment.",
-      };
-    }
-
-    downloading = true;
-
     try {
       await deps.runtime.downloadUpdate();
+      if (cachedUpdateInfo?.version !== readyVersion) {
+        return {
+          installed: false,
+          version: currentVersion,
+          message: "A newer update was found and will be installed later.",
+        };
+      }
       downloadedUpdateVersion = readyVersion;
-      downloading = false;
       await performQuitAndInstall(deps.runtime, onBeforeQuit);
 
       return {
@@ -334,7 +299,6 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
         message: "Update downloaded. The app will restart shortly.",
       };
     } catch (error) {
-      downloading = false;
       const message = error instanceof Error ? error.message : String(error);
       deps.reportInstallError?.(message);
       return {
@@ -345,8 +309,33 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
     }
   }
 
+  async function installUpdateOnQuit({
+    currentVersion,
+    releaseChannel,
+  }: {
+    currentVersion: string;
+    releaseChannel: AppReleaseChannel;
+  }): Promise<boolean> {
+    if (!deps.isPackaged() || !downloadedUpdateVersion) {
+      return false;
+    }
+
+    const check = await checkForAppUpdate({
+      currentVersion,
+      releaseChannel,
+      intent: "automatic",
+    });
+    if (!check.hasUpdate) {
+      return false;
+    }
+
+    const result = await installCachedUpdate(currentVersion);
+    return result.installed;
+  }
+
   return {
     checkForAppUpdate,
     downloadAndInstallUpdate,
+    installUpdateOnQuit,
   };
 }

packages/desktop/src/features/auto-updater.test.ts

@@ -19,18 +19,8 @@ import {
   resolveStagingUserId,
   rolloutManifestSchema,
   shouldAdmitToRollout,
-  shouldAutoInstallOnQuit,
 } from "./auto-updater";
 
-describe("shouldAutoInstallOnQuit", () => {
-  it("auto-installs on quit everywhere except Linux AppImage", () => {
-    expect(shouldAutoInstallOnQuit({ platform: "linux", isAppImage: true })).toBe(false);
-    expect(shouldAutoInstallOnQuit({ platform: "linux", isAppImage: false })).toBe(true);
-    expect(shouldAutoInstallOnQuit({ platform: "darwin", isAppImage: false })).toBe(true);
-    expect(shouldAutoInstallOnQuit({ platform: "win32", isAppImage: false })).toBe(true);
-  });
-});
-
 describe("shouldAdmitToRollout", () => {
   it("admits beta, missing rollout hours, zero-hour rollout, and missing release date", () => {
     expect(

packages/desktop/src/features/auto-updater.ts

@@ -76,31 +76,16 @@ export function getStagingUserId(): Promise<string> {
   return cachedStagingUserIdPromise;
 }
 
-// AppImages have no install step. electron-updater "installs" by unlinking the
-// running file and mv-ing the downloaded one into place; on app quit it does this
-// via a *blocking* execFileSync(newAppImage, { APPIMAGE_EXIT_AFTER_INSTALL: "true" }).
-// That env var is only honored by AppImageLauncher, so without it the freshly
-// launched process boots the full app and never exits — the quit hangs forever,
-// with the old binary already deleted. We therefore install AppImages only on
-// explicit quitAndInstall (the "Update now" button), which takes the non-blocking
-// spawn path. Every other target keeps auto-install-on-quit, which works there.
-export function shouldAutoInstallOnQuit(input: {
-  platform: NodeJS.Platform;
-  isAppImage: boolean;
-}): boolean {
-  return !(input.platform === "linux" && input.isAppImage);
-}
-
 class ElectronAppUpdateRuntime implements AppUpdateRuntime {
   private configured = false;
 
   configure(input: AppUpdateRuntimeConfiguration): void {
     autoUpdater.autoDownload = true;
     autoUpdater.autoRunAppAfterInstall = true;
-    autoUpdater.autoInstallOnAppQuit = shouldAutoInstallOnQuit({
-      platform: process.platform,
-      isAppImage: Boolean(process.env.APPIMAGE),
-    });
+    // Paseo revalidates the current manifest before explicitly installing on quit.
+    // Electron's built-in handler would install an older download without checking
+    // whether a newer release has superseded it.
+    autoUpdater.autoInstallOnAppQuit = false;
     autoUpdater.allowPrerelease = input.releaseChannel === "beta";
     autoUpdater.channel = input.releaseChannel === "beta" ? "beta" : "latest";
     autoUpdater.allowDowngrade = false;
@@ -194,3 +179,13 @@ export async function downloadAndInstallUpdate(
     onBeforeQuit,
   );
 }
+
+export async function installAppUpdateOnQuit({
+  currentVersion,
+  releaseChannel,
+}: {
+  currentVersion: string;
+  releaseChannel: AppReleaseChannel;
+}): Promise<boolean> {
+  return appUpdateService.installUpdateOnQuit({ currentVersion, releaseChannel });
+}

packages/desktop/src/main.ts

@@ -85,6 +85,7 @@ import {
 import { runDesktopStartup } from "./desktop-startup.js";
 import { autoUpdateInstalledSkills } from "./integrations/skills/index.js";
 import { registerBrowserAutomationIpc } from "./features/browser-automation/ipc.js";
+import { installAppUpdateOnQuit } from "./features/auto-updater.js";
 
 const DEV_SERVER_URL = process.env.EXPO_DEV_URL ?? "http://localhost:8081";
 const APP_SCHEME = "paseo";
@@ -998,9 +999,19 @@ app.on(
         stopDaemon: () => stopDesktopDaemonViaCli("quit"),
         showShutdownFeedback: showDaemonShutdownDialog,
       }),
+    installAppUpdateOnQuit: async () => {
+      const settings = await getDesktopSettingsStore().get();
+      return installAppUpdateOnQuit({
+        currentVersion: app.getVersion(),
+        releaseChannel: settings.releaseChannel,
+      });
+    },
     onStopError: (error) => {
       log.error("[desktop daemon] failed to stop managed daemon on quit", error);
     },
+    onUpdateError: (error) => {
+      log.error("[auto-updater] failed to validate downloaded update on quit", error);
+    },
   }),
 );