Bug 1683713 - Ensure the restoring tab is not reused in addMultipleTabs; r=dao

Differential Revision: https://phabricator.services.mozilla.com/D100249

browser/base/content/tabbrowser.js

@@ -2878,7 +2878,11 @@
 
         // Re-use existing selected tab if possible to avoid the overhead of
         // selecting a new tab.
-        if (select && this.selectedTab.userContextId == userContextId) {
+        if (
+          select &&
+          this.selectedTab.userContextId == userContextId &&
+          !SessionStore.isTabRestoring(this.selectedTab)
+        ) {
           tabWasReused = true;
           tab = this.selectedTab;
           if (!tabData.pinned) {

browser/components/sessionstore/SessionStore.jsm

@@ -298,6 +298,11 @@ var SessionStore = {
     SessionStoreInternal.setTabState(aTab, aState);
   },
 
+  // Return whether a tab is restoring.
+  isTabRestoring(aTab) {
+    return TAB_STATE_FOR_BROWSER.has(aTab.linkedBrowser);
+  },
+
   getInternalObjectState(obj) {
     return SessionStoreInternal.getInternalObjectState(obj);
   },