feat: Make sure sessions are correctly migrated on first run, b=no-bug, c=workspaces

prefs/zen/session-store.yaml

@@ -10,3 +10,6 @@
 
 - name: zen.session-store.restore-unsynced-windows
   value: true
+
+- name: zen.session-store.reduce-sessionstore-write-size
+  value: true

src/browser/components/sessionstore/SessionSaver-sys-mjs.patch

@@ -1,5 +1,5 @@
 diff --git a/browser/components/sessionstore/SessionSaver.sys.mjs b/browser/components/sessionstore/SessionSaver.sys.mjs
-index 9141793550f7c7ff6aa63d4c85bf571b4499e2d0..6906fd9be7ae6ca4316133e0d6552b797c54a7ec 100644
+index 9141793550f7c7ff6aa63d4c85bf571b4499e2d0..a4ce5de45f13eaa22803083eccb4e48a054fee39 100644
 --- a/browser/components/sessionstore/SessionSaver.sys.mjs
 +++ b/browser/components/sessionstore/SessionSaver.sys.mjs
 @@ -20,6 +20,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
@@ -27,3 +27,24 @@ index 9141793550f7c7ff6aa63d4c85bf571b4499e2d0..6906fd9be7ae6ca4316133e0d6552b79
      return this._writeState(state);
    },
  
+@@ -372,7 +374,19 @@ var SessionSaverInternal = {
+     // Write (atomically) to a session file, using a tmp file. Once the session
+     // file is successfully updated, save the time stamp of the last save and
+     // notify the observers.
+-    return lazy.SessionFile.write(state).then(
++    let stateToWrite = Cu.cloneInto(state, {});
++    if (Services.prefs.getBoolPref("zen.session-store.reduce-sessionstore-write-size", true)) {
++      for (let i = 0; i < stateToWrite.windows.length; i++) {
++        let win = stateToWrite.windows[i];
++        if (win.isPopup || win.isTaskbarTab || win.isZenUnsynced) {
++          continue;
++        }
++        win.tabs = [];
++        win.folders = [];
++        win.groups = [];
++      }
++    }
++    return lazy.SessionFile.write(stateToWrite).then(
+       () => {
+         this.updateLastSaveTime();
+         if (!lazy.RunState.isRunning) {

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..ffb22990e7d9e1b79f276fe5c1eb38f2b869a57b 100644
+index 86600ffb5178599ab23270a964064ca657a3283f..e7014e5bce547d37ec92377a95bad5be4d52152e 100644
 --- a/browser/components/sessionstore/SessionStartup.sys.mjs
 +++ b/browser/components/sessionstore/SessionStartup.sys.mjs
 @@ -40,6 +40,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
@@ -23,7 +23,7 @@ index 86600ffb5178599ab23270a964064ca657a3283f..ffb22990e7d9e1b79f276fe5c1eb38f2
        this._initialState = parsed;
      }
  
-+    lazy.ZenSessionStore.onFileRead(this._initialState);
++    this._initialState = lazy.ZenSessionStore.onFileRead(this._initialState);
 +
      if (this._initialState == null) {
        // No valid session found.

src/browser/components/sessionstore/TabState-sys-mjs.patch

@@ -1,5 +1,5 @@
 diff --git a/browser/components/sessionstore/TabState.sys.mjs b/browser/components/sessionstore/TabState.sys.mjs
-index 82721356d191055bec0d4b0ca49e481221988801..238d6ae1a4261e098d1e986e3c3df813d9d625f3 100644
+index 82721356d191055bec0d4b0ca49e481221988801..68437e6f9fa54fc75ca9e24d738e8afcd0ea22f8 100644
 --- a/browser/components/sessionstore/TabState.sys.mjs
 +++ b/browser/components/sessionstore/TabState.sys.mjs
 @@ -85,7 +85,24 @@ class _TabState {
@@ -8,7 +8,7 @@ index 82721356d191055bec0d4b0ca49e481221988801..238d6ae1a4261e098d1e986e3c3df813
  
 +    tabData.zenWorkspace = tab.getAttribute("zen-workspace-id");
 +    tabData.zenSyncId = tab.getAttribute("id");
-+    tabData.zenEssential = tab.getAttribute("zen-essential");
++    tabData.zenEssential = tab.getAttribute("zen-essential") === "true";
 +    tabData.pinned = tabData.pinned || tabData.zenEssential;
 +    tabData.zenDefaultUserContextId = tab.getAttribute("zenDefaultUserContextId");
 +    tabData.zenPinnedIcon = tab.getAttribute("zen-pinned-icon");

src/zen/sessionstore/ZenSessionManager.sys.mjs

@@ -198,7 +198,7 @@ export class nsZenSessionManager {
    */
   onFileRead(initialState) {
     if (!lazy.gWindowSyncEnabled) {
-      return;
+      return initialState;
     }
     // For the first time after migration, we restore the tabs
     // That where going to be restored by SessionStore. The sidebar
@@ -235,19 +235,26 @@ export class nsZenSessionManager {
       "zen.session-store.restore-unsynced-windows",
       true
     );
-    this.log(`Restoring Zen session data into ${initialState.windows?.length || 0} windows`);
-    for (let i = 0; i < initialState.windows.length; i++) {
-      let winData = initialState.windows[i];
-      if (winData.isZenUnsynced) {
-        if (!allowRestoreUnsynced) {
-          // We don't wan't to restore any unsynced windows with the sidebar data.
-          this.log("Skipping restore of unsynced window");
-          delete initialState.windows[i];
+    if (!this._shouldRunMigration) {
+      this.log(`Restoring Zen session data into ${initialState.windows?.length || 0} windows`);
+      for (let i = 0; i < initialState.windows.length; i++) {
+        let winData = initialState.windows[i];
+        if (winData.isZenUnsynced) {
+          if (!allowRestoreUnsynced) {
+            // We don't wan't to restore any unsynced windows with the sidebar data.
+            this.log("Skipping restore of unsynced window");
+            delete initialState.windows[i];
+          }
+          continue;
         }
-        continue;
+        this.#restoreWindowData(winData);
       }
-      this.#restoreWindowData(winData);
+    } else {
+      this.log("Saving windata state after migration");
+      this.saveState(initialState);
     }
+    delete this._shouldRunMigration;
+    return initialState;
   }
 
   get #sidebar() {
@@ -304,9 +311,7 @@ export class nsZenSessionManager {
     }
     // Save the state to the sidebar object so that it gets written
     // to the session file.
-    this.saveState(initialState);
     delete this._migrationData;
-    delete this._shouldRunMigration;
   }
 
   /**

src/zen/sessionstore/ZenWindowSync.sys.mjs

@@ -56,6 +56,7 @@ const SYNC_FLAG_ICON = 1 << 1;
 const SYNC_FLAG_MOVE = 1 << 2;
 
 class nsZenWindowSync {
+  #initialized = false;
   constructor() {}
 
   /**
@@ -139,9 +140,10 @@ class nsZenWindowSync {
   }
 
   init() {
-    if (!lazy.gWindowSyncEnabled) {
+    if (!lazy.gWindowSyncEnabled || this.#initialized) {
       return;
     }
+    this.#initialized = true;
     for (let topic of OBSERVING) {
       Services.obs.addObserver(this, topic);
     }
@@ -151,6 +153,10 @@ class nsZenWindowSync {
   }
 
   uninit() {
+    if (!this.#initialized) {
+      return;
+    }
+    this.#initialized = false;
     for (let topic of OBSERVING) {
       Services.obs.removeObserver(this, topic);
     }

src/zen/workspaces/ZenWorkspaces.mjs

@@ -1129,6 +1129,7 @@ class nsZenWorkspaces {
         (tab.pinned && tab.hasAttribute("zen-empty-tab") && !tab.group)
       ) {
         // Remove any tabs where their workspace doesn't exist anymore
+        this.log("Removed zombie tab from non-existing workspace", tab);
         gBrowser.unpinTab(tab);
         gBrowser.removeTab(tab, {
           skipSessionStore: true,