From 76966ee1c3564e7f6b95bcc92300a7221abcf7b7 Mon Sep 17 00:00:00 2001
From: "mr. m" <mr.m@tuta.com>
Date: Mon, 9 Feb 2026 23:14:51 +0100
Subject: [PATCH] feat: Make sure to always restore tabs from a crash,
 b=no-bug, c=no-component

---
 .../sessionstore/SessionStartup-sys-mjs.patch | 13 ++++++++--
 .../sessionstore/ZenSessionManager.sys.mjs    | 24 +++++++++++++++++--
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/src/browser/components/sessionstore/SessionStartup-sys-mjs.patch b/src/browser/components/sessionstore/SessionStartup-sys-mjs.patch
index 2dceba548..b36096b06 100644
--- a/src/browser/components/sessionstore/SessionStartup-sys-mjs.patch
+++ b/src/browser/components/sessionstore/SessionStartup-sys-mjs.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/sessionstore/SessionStartup.sys.mjs b/browser/components/sessionstore/SessionStartup.sys.mjs
-index 86600ffb5178599ab23270a964064ca657a3283f..e7014e5bce547d37ec92377a95bad5be4d52152e 100644
+index 86600ffb5178599ab23270a964064ca657a3283f..97975af7822a157eafe02ec8bbebdf1a6b564ccb 100644
 --- a/browser/components/sessionstore/SessionStartup.sys.mjs
 +++ b/browser/components/sessionstore/SessionStartup.sys.mjs
 @@ -40,6 +40,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
@@ -28,7 +28,16 @@ index 86600ffb5178599ab23270a964064ca657a3283f..e7014e5bce547d37ec92377a95bad5be
      if (this._initialState == null) {
        // No valid session found.
        this._sessionType = this.NO_SESSION;
-@@ -336,12 +339,7 @@ export var SessionStartup = {
+@@ -276,6 +279,8 @@ export var SessionStartup = {
+         `Previous shutdown ok? ${this._previousSessionCrashed}, reason: ${previousSessionCrashedReason}`
+       );
+ 
++      lazy.ZenSessionStore.onCrashCheckpoints(this._initialState);
++
+       Services.obs.addObserver(this, "sessionstore-windows-restored", true);
+ 
+       if (this.sessionType == this.NO_SESSION) {
+@@ -336,12 +341,7 @@ export var SessionStartup = {
    isAutomaticRestoreEnabled() {
      if (this._resumeSessionEnabled === null) {
        this._resumeSessionEnabled =
diff --git a/src/zen/sessionstore/ZenSessionManager.sys.mjs b/src/zen/sessionstore/ZenSessionManager.sys.mjs
index 8e5eaa3df..ef163af69 100644
--- a/src/zen/sessionstore/ZenSessionManager.sys.mjs
+++ b/src/zen/sessionstore/ZenSessionManager.sys.mjs
@@ -10,6 +10,7 @@ const lazy = {};
 ChromeUtils.defineESModuleGetters(lazy, {
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.sys.mjs",
   SessionStore: "resource:///modules/sessionstore/SessionStore.sys.mjs",
+  SessionStartup: "resource:///modules/sessionstore/SessionStartup.sys.mjs",
   gWindowSyncEnabled: "resource:///modules/zen/ZenWindowSync.sys.mjs",
   gSyncOnlyPinnedTabs: "resource:///modules/zen/ZenWindowSync.sys.mjs",
   DeferredTask: "resource://gre/modules/DeferredTask.sys.mjs",
@@ -231,6 +232,13 @@ export class nsZenSessionManager {
     );
   }
 
+  get #shouldRestoreFromCrash() {
+    return (
+      lazy.SessionStartup.previousSessionCrashed &&
+      Services.prefs.getBoolPref("browser.sessionstore.resume_from_crash")
+    );
+  }
+
   /**
    * Called when the session file is read. Restores the sidebar data
    * into all windows.
@@ -270,9 +278,22 @@ export class nsZenSessionManager {
         },
       ];
     }
+    return initialState;
+  }
+
+  /**
+   * Called after @onFileRead, when session startup has crash checkpoint information available.
+   * Restores the sidebar data into all windows, and runs any crash checkpoint related logic,
+   * such as restoring only pinned tabs if the previous session was not crashed and the user
+   * preference is set to do so.
+   *
+   * @param {object} initialState
+   *        The initial session state read from the session file, possibly modified by onFileRead.
+   */
+  onCrashCheckpoints(initialState) {
     // When we don't have browser.startup.page set to resume session,
     // we only want to restore the pinned tabs into the new windows.
-    if (this.#shouldRestoreOnlyPinned && this.#sidebar?.tabs) {
+    if (this.#shouldRestoreOnlyPinned && !this.#shouldRestoreFromCrash && this.#sidebar?.tabs) {
       this.log("Restoring only pinned tabs into windows");
       const sidebar = this.#sidebar;
       sidebar.tabs = (sidebar.tabs || []).filter((tab) => tab.pinned);
@@ -304,7 +325,6 @@ export class nsZenSessionManager {
       this.saveState(Cu.cloneInto(initialState, {}));
     }
     delete this._shouldRunMigration;
-    return initialState;
   }
 
   get #sidebar() {