tor-browser

commit 1a0061c0f6b06894dbf7899a15fe0b858793b8f1
parent c198264d6626ccba80187461ee755149186c55fb
Author: Greg Stoll <gstoll@mozilla.com>
Date:   Wed,  8 Oct 2025 23:48:25 +0000

Bug 1968297 - ensure windows that are occluded after session restore draw a taskbar preview (again x2) r=win-reviewers,sessionstore-reviewers,handyman,sfoster

The previous patches have made this better, but there's still a problem
if a window gets resized during session restore. (it's easiest to see this
if its natural size is small and then it gets maximized)

There are a number of ways to fix this, but I think delaying the "session
was restored" message until the window is resized makes sense, and that means
we can just extend the check for "should I pretend I'm not occluded" to
include if session restoring is in progress.

Differential Revision: https://phabricator.services.mozilla.com/D267426

Diffstat:
M
browser/components/sessionstore/SessionStore.sys.mjs
 | 
29
++++++++++++++++++++---------
M
browser/components/sessionstore/test/browser_637020.js
 | 
5
++++-
M
widget/windows/nsWindowGfx.cpp
 | 
5
+++--

3 files changed, 27 insertions(+), 12 deletions(-)
diff --git a/browser/components/sessionstore/SessionStore.sys.mjs b/browser/components/sessionstore/SessionStore.sys.mjs
@@ -5916,14 +5916,6 @@ var SessionStoreInternal = {
     arrowScrollbox.smoothScroll = smoothScroll;
 
     Glean.sessionRestore.restoreWindow.stopAndAccumulate(timerId);
-
-    this._setWindowStateReady(aWindow);
-
-    this._sendWindowRestoredNotification(aWindow);
-
-    Services.obs.notifyObservers(aWindow, NOTIFY_SINGLE_WINDOW_RESTORED);
-
-    this._sendRestoreCompletedNotifications();
   },
 
   /**
@@ -5986,9 +5978,11 @@ var SessionStoreInternal = {
   _restoreWindowsFeaturesAndTabs(windows) {
     // First, we restore window features, so that when users start interacting
     // with a window, we don't steal the window focus.
+    let resizePromises = [];
     for (let window of windows) {
       let state = this._statesToRestore[WINDOW_RESTORE_IDS.get(window)];
-      this.restoreWindowFeatures(window, state.windows[0]);
+      // Wait for these promises after we've restored data into them below.
+      resizePromises.push(this.restoreWindowFeatures(window, state.windows[0]));
     }
 
     // Then we restore data into windows.
@@ -6001,6 +5995,20 @@ var SessionStoreInternal = {
       );
       WINDOW_RESTORE_ZINDICES.delete(window);
     }
+    for (let resizePromise of resizePromises) {
+      resizePromise.then(resizedWindow => {
+        this._setWindowStateReady(resizedWindow);
+
+        this._sendWindowRestoredNotification(resizedWindow);
+
+        Services.obs.notifyObservers(
+          resizedWindow,
+          NOTIFY_SINGLE_WINDOW_RESTORED
+        );
+
+        this._sendRestoreCompletedNotifications();
+      });
+    }
   },
 
   /**
@@ -6505,6 +6513,7 @@ var SessionStoreInternal = {
       }
     }
 
+    let promiseParts = Promise.withResolvers();
     aWindow.setTimeout(() => {
       this.restoreDimensions(
         aWindow,
@@ -6516,7 +6525,9 @@ var SessionStoreInternal = {
         aWinData.sizemodeBeforeMinimized || ""
       );
       this.restoreSidebar(aWindow, aWinData.sidebar, aWinData.isPopup);
+      promiseParts.resolve(aWindow);
     }, 0);
+    return promiseParts.promise;
   },
 
   /**
diff --git a/browser/components/sessionstore/test/browser_637020.js b/browser/components/sessionstore/test/browser_637020.js
@@ -46,6 +46,9 @@ add_task(async function test() {
   let backupState = SessionStore.getBrowserState();
   SessionStore.setBrowserState(JSON.stringify(TEST_STATE));
   let win = await promiseWindow;
+  let delayedStartupFinished = new Promise(resolve =>
+    whenDelayedStartupFinished(win, resolve)
+  );
   let restoring = promiseWindowRestoring(win);
   let restored = promiseWindowRestored(win);
   await restoring;
@@ -58,7 +61,7 @@ add_task(async function test() {
 
   // The history has now been restored and the tabs are loading. The data must
   // now come from the window, if it's correctly been marked as dirty before.
-  await new Promise(resolve => whenDelayedStartupFinished(win, resolve));
+  await delayedStartupFinished;
   info("the delayed startup has finished");
   checkWindows();
 
diff --git a/widget/windows/nsWindowGfx.cpp b/widget/windows/nsWindowGfx.cpp
@@ -317,9 +317,10 @@ void nsWindow::NotifyOcclusionState(mozilla::widget::OcclusionState aState) {
   if (mFrameState->GetSizeMode() == nsSizeMode_Minimized) {
     isFullyOccluded = false;
   }
-  if (isFullyOccluded && !mHasBeenShown) {
+  if (isFullyOccluded && (!mHasBeenShown || nsWindow::sIsRestoringSession)) {
     // Don't mark a newly-created window as occluded until
-    // it renders a taskbar icon. (bug 1968297)
+    // it is finished being restored (including sizing) and has been shown once.
+    // (bug 1968297)
     isFullyOccluded = false;
   }